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01.4IB.65120 PowlVac 38™ ARM
Automatic Racking Mechanism
Vacuum Circuit Breaker
38kV, 1200A & 2000A
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PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
Contact Information
Powell Electrical Systems, Inc.
powellind.com
[email protected]
Service Division
PO Box 12818
Houston, Texas 77217-2818
Tel: 713.944.6900
Fax: 713.948.4569
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01.4IB.65120
Signal Words
Qualified Person
As stated in ANSI Z535.4-2007, the signal word is
a word that calls attention to the safety sign and
designates a degree or level of hazard seriousness.
The signal words for product safety signs are
“Danger”, “Warning”, “Caution” and “Notice”.
These words are defined as:
For the purposes of this manual, a qualified
person, as stated in NFPA 70E®, is one who has
skills and knowledge related to the construction
and operation of the electrical equipment and
installations and has received safety training to
recognize and avoid the hazards involved. In
addition to the above qualifications, one must also
be:
!
DANGER
DANGER indicates an imminently hazardous
situation which, if not avoided, will result in
death or serious injury.
!
WARNING
WARNING indicates a potentially hazardous
situation which, if not avoided, could result in
death or serious injury.
!
1. trained and authorized to energize,
deenergize, clear, ground, and tag circuits
and equipment in accordance with
established safety practices.
2. trained in the proper care and use of
personal protective equipment (PPE)
such as rubber gloves, hard hat, safety
glasses or face shields, flash clothing, etc.,
in accordance with established safety
practices.
3. trained in rendering first aid if necessary.
CAUTION
CAUTION, used with the safety alert symbol,
indicates a hazardous situation which, if not
avoided, could result in minor or moderate
injury.
CAUTION
CAUTION, used without the safety alert
symbol, is used to address practices not
related to personal injury.
NOTICE
NOTICE is used to address practices not related
to personal injury.
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Vacuum Circuit Breaker
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01.4IB.65120
Contents
Ch 1 General Information..................................................................................................1
A. Scope.................................................................................................................................................................2
B.Purpose..............................................................................................................................................................2
C. Instruction Bulletins Available Electronically. ....................................................................................................2
D. Associated Instruction Bulletins..........................................................................................................................2
Ch 2 Safety.........................................................................................................................3
A.
B.
C.
D.
E.
F.
Safe Work Condition..........................................................................................................................................3
Safety Guidelines................................................................................................................................................3
General. ............................................................................................................................................................4
Specific...............................................................................................................................................................4
X-Rays...............................................................................................................................................................5
Safety Labels......................................................................................................................................................5
Ch 3 Equipment Description..............................................................................................6
A. General. ............................................................................................................................................................6
B.The Stored Energy Mechanism.............................................................................................................................6
1) Mechanical Description........................................................................................................................................................... 6
2) Electrical Description..............................................................................................................................................................16
C. Automatic Racking Mechanism. ........................................................................................................................ 19
1) General Description................................................................................................................................................................19
2) Racking Mechanism...............................................................................................................................................................20
D.Circuit Breaker Compartment Interfaces............................................................................................................ 21
1)
2)
3)
4)
5)
6)
Primary Disconnecting Devices...........................................................................................................................................21
Secondary Disconnecting Devices......................................................................................................................................21
MOC (Mechanism Operated Cell Switch) Actuator.........................................................................................................21
TOC (Truck Operated Cell Switch) Actuator......................................................................................................................21
Ground Connection................................................................................................................................................................21
Anti-Rollout Latch...................................................................................................................................................................22
E.Vacuum Interrupters........................................................................................................................................ 22
F.Vacuum Interrupter Connections...................................................................................................................... 22
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PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
Contents
Ch 4 Installation..............................................................................................................23
A.Receiving......................................................................................................................................................... 23
B.Handling......................................................................................................................................................... 23
C. Storage. ......................................................................................................................................................... 24
D.Placing the Circuit Breaker Into Service. ........................................................................................................... 25
1)
2)
3)
4)
5)
6)
High Voltage Insulation Integrity........................................................................................................................................25
Vacuum Integrity.....................................................................................................................................................................26
Control Voltage Insulation Integrity...................................................................................................................................27
Mechanical Operation Check...............................................................................................................................................28
Electrical Operation Check....................................................................................................................................................28
Emergency Racking Mechanism Check.............................................................................................................................29
E. Inserting the Circuit Breaker Into the Circuit Breaker Compartment. ................................................................... 30
1) Prior to Inserting the Circuit Breaker into the Circuit Breaker Compartment...........................................................30
2) Inserting the Circuit Breaker to the Test/Disconnected Position..................................................................................31
3) Inserting the Circuit Breaker to the Connected Position................................................................................................32
F.Removing the Circuit Breaker From the Circuit Breaker Compartment.................................................................. 34
1) Removing the Circuit Breaker from the Connected to the Test/Disconnected Position.........................................34
2) Removing the Circuit Breaker from the Test/Disconnected Position
out of the Circuit Breaker Compartment...........................................................................................................................34
Ch 5 Maintenance............................................................................................................35
A. General Description......................................................................................................................................... 35
1)Introduction..............................................................................................................................................................................35
2) Inspection and Cleaning.......................................................................................................................................................36
B. Mechanism Area.............................................................................................................................................. 37
1) Mechanical Operation...........................................................................................................................................................37
2)Lubrication................................................................................................................................................................................37
3) Closing Spring Removal.........................................................................................................................................................41
4) Slow Closing of Mechanism..................................................................................................................................................42
5) Mechanism Adjustments.......................................................................................................................................................42
6) Electrical Operation................................................................................................................................................................47
C.Vacuum Interrupter and Contact Area.............................................................................................................. 47
1) Vacuum Interrupter and Contact Erosion.........................................................................................................................47
2) Vacuum Integrity.....................................................................................................................................................................47
3) Mechanical Adjustment of Vacuum Interrupters..................................................................................................................47
D.Optional Maintenance Procedures.................................................................................................................... 48
1) High Potential Tests................................................................................................................................................................48
2)Timing .......................................................................................................................................................................................48
3) Primary Resistance Check.....................................................................................................................................................49
ii
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01.4IB.65120
Contents
Ch 6 Recommended Renewal Parts and Replacement Procedures................................50
A.Ordering Instructions...................................................................................................................................... 50
B.Recommended Renewal Parts............................................................................................................................ 50
C.Replacement Procedures. ................................................................................................................................. 50
1) Vacuum Interrupter Assembly..............................................................................................................................................51
2) Closing Coil Assembly............................................................................................................................................................54
3) Primary Shunt Trip Coil Assembly.......................................................................................................................................54
4) Secondary Shunt Trip Coil Assembly..................................................................................................................................54
5) Undervoltage Device Assembly (UV)..................................................................................................................................54
6) Charging Motor Assembly....................................................................................................................................................54
7) Anti-Pump Relay Assembly...................................................................................................................................................54
8) Latch Check Switch.................................................................................................................................................................54
9) Motor Cutoff Switch Assembly.............................................................................................................................................54
10) Auxiliary Switch.......................................................................................................................................................................54
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PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
Figures
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
Figure 11
Figure 12
Figure 13
Figure 14
Figure 15
Figure 16
Figure 17
Figure 18
Figure 19
Figure 20
Figure 21
Figure 22
Figure 23
Figure 24
iv
Front View of PowlVac 38™ ARM Circuit Breaker with Cover..........................7
Rear View of PowlVac 38™ ARM Circuit Breaker.............................................8
Operating Pushrod Assembly of PowlVac 38™ ARM Circuit Breaker..............9
Ground Connection of PowlVac 38™ ARM Circuit Breaker.............................9
Front View of PowlVac 38™ ARM Circuit Breaker without Cover..................11
Close-Up Front View of PowlVac 38™ ARM Circuit Breaker Mechanism.......12
Cam and Fundamental Linkage Positions....................................................13
Mechanical and Trip Linkages.......................................................................14
Operation Sequence......................................................................................17
Typical Control Scheme.................................................................................18
Circuit Breaker in Shipping Carton................................................................23
Lifting the Circuit Breaker by Crane..............................................................24
Secondary Disconnecting Devices................................................................32
Lubrication.....................................................................................................39
Lubrication (cont)..........................................................................................40
Main Closing Spring Assembly Compressed for Removal............................41
Main Closing Spring Assembly Installed.......................................................41
Primary & Secondary Trip Prop Adjustment.................................................43
Feeler Gauge..................................................................................................44
Latch Check Switch Adjustment....................................................................46
Vacuum Interrupter Assembly Drawing (38kV, 1200A)................................55
Vacuum Interrupter Assembly Drawing (38kV, 2000A)................................57
Primary Current Path.....................................................................................59
Control Devices..............................................................................................61
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01.4IB.65120
Tables
Table A Field Dielectric Test Values...................................................................................26
Table B Lubrication...........................................................................................................38
Table C Timing...................................................................................................................48
Table D Primary Resistance..............................................................................................49
Table E Vacuum Interrupter Assembly Parts List - 1200A................................................56
Table F Vacuum Interrupter Assembly Parts List - 2000A................................................58
Table G Primary Current Path...........................................................................................59
Table H Control Devices....................................................................................................60
Table I Miscellaneous Parts..............................................................................................62
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PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
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01.4IB.65120
Ch 1 General Information
!
WARNING
The equipment described in this document may contain high voltages and currents which can
cause serious injury or death.
The equipment is designed for use, installation, and maintenance by qualified users of such
equipment having experience and training in the field of high voltage electricity. This document
and all other documentation shall be fully read, understood, and all warnings and cautions
shall be abided by. If there are any discrepancies or questions, the user shall contact Powell
immediately at 1.800.480.7273.
!
WARNING
Before any adjustment, servicing, part replacement, or any other act is performed requiring
physical contact with the electrical working components or wiring of this equipment, the power
supply must be disconnected. Failure to follow this warning may result in injury or death.
NOTICE
The information in this instruction bulletin is not intended to explain all details or variations of the
Powell equipment, nor to provide for every possible contingency or hazard to be met in connection
with installation, testing, operation, and maintenance of the equipment. For additional
information and instructions for particular problems, which are not presented sufficiently for the
user’s purposes, contact Powell at 1.800.480.7273.
NOTICE
Powell reserves the right to discontinue and to change specifications at any time without incurring
any obligation to incorporate new features in products previously sold.
General Information
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PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
A. Scope
The information in this instruction bulletin
describes the following PowlVac 38™ ARM
(Automatic Racking Mechanism) vacuum
circuit breakers:
•
38PV40ARM - 1200A & 2000A
B.Purpose
The information in this instruction bulletin is
intended to provide information required to
properly operate and maintain the
PowlVac 38 ARM vacuum circuit breakers
described in Ch 1 General Information,
A. Scope.
!
Be sure to follow the appropriate safety
precaution while handling any of the
equipment. Failure to do so may result in
serious injury or death.
To the extent required, the products described
herein meet the applicable ANSI, IEEE, and
NEMA Standards; however, no such assurance
is given with respect to local codes and
ordinances which may vary greatly.
C. Instruction Bulletins Available Electronically
NOTICE
This instruction bulletin provides:
1. Safety guidelines
2. General descriptions of the operation
and maintenance of the PowlVac 38 ARM
vacuum circuit breaker
3. Instructions for installation and placing the
circuit breaker into service
4. Instructions for part replacement
5. Information for ordering renewal parts
6. Procedure for critical adjustments
7. Illustrations, photographs, and description
of the circuit breaker
The illustrations contained in this document
may not represent the exact construction
details of each particular type of circuit breaker.
The illustrations in this document are provided
as general information to aid in showing
component locations only.
All illustrations and photos are shown using
deenergized equipment.
Changes to the instruction bulletin may be
implemented at any time and without notice.
Go to powellind.com to ensure use of the
current instruction bulletin for the Powell
equipment.
For more information visit powellind.com. To
contact the Powell Service Division call
1.800.480.7273 or 713.944.6900, or email
[email protected]
For specific questions or comments pertaining
to this instruction bulletin email
[email protected] with the IB
number in the subject line.
D. Associated Instruction Bulletins
•
•
2
WARNING
01.4IB.65202A PowlVac 38-AR™ Arc
Resistant Metal-Clad Switchgear 1200A &
2000A with CDS Circuit Breakers
01.4IB.51808A Vacuum Type Remote
Racking Device
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General Information
01.4IB.65120
Ch 2 Safety
A. Safe Work Condition
The information in Section A is quoted from
NFPA 70E 2012 - Article 120, 120.1 Establishing an
Electrically Safe Work Condition.
120.1 Process of Achieving an Electrically Safe
Work Condition
1. Determine all possible sources of electrical
supply to the specific equipment. Check
applicable up-to-date drawings, diagrams,
and identification tags.
2. After properly interrupting the load current,
OPEN the disconnecting device(s) for each
source.
3. Wherever possible, visually verify that all
blades of the disconnecting devices are
fully OPEN or that drawout type circuit
breakers are withdrawn to the fully
disconnected position.
4. Apply lockout/tagout devices in accordance
with a documented and established policy.
5. Use an adequately rated voltage detector
to test each phase conductor or circuit part
to verify they are deenergized. Test each
phase conductor or circuit part both
phase-to-phase, and phase-to-ground.
Before and after each test, determine
that the voltage detector is operating
satisfactorily.
Informational Note: See ANSI/ISA-61010-1
(82.02.01)/UL 61010-1, Safety Requirements
for Electrical Equipment for Measurement,
Control, and Laboratory Use - Part 1: General
Requirements, for rating and design
requirements for voltage measurement
and test instruments intended for use on
electrical systems 1000 V and below.
Safety
6. Where the possibility of induced voltages
or stored electrical energy exists, ground
the phase conductors or circuit parts
before touching them. Where it could be
reasonably anticipated that the conductors
or circuit parts being deenergized
could contact other exposed energized
conductors or circuit parts, apply ground
connecting devices rated for the available
fault duty.
B. Safety Guidelines
Study this instruction bulletin and all other
associated documentation before uncrating
the circuit breakers.
Each user has the responsibility to instruct
and supervise all personnel associated with
usage, installation, operation, and maintenance
of this equipment on all safety procedures.
Furthermore, each user has the responsibility of
establishing a safety program for each type of
equipment encountered.
The circuit breakers described in this
instruction bulletin are operated by a
high-energy, high-speed mechanism that
is interlocked to provide specific operating
sequences. It is mandatory that the following
rules be observed to ensure the safety of
personnel associated with usage, installation,
operation, and maintenance of these circuit
breakers.
The safety rules in this instruction bulletin are
not intended to be a complete safety program.
The rules are intended to cover only some of the
important aspects of personnel safety related to
PowlVac 38™ ARM vacuum circuit breakers.
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PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
C. General
1. Only supervised and qualified personnel
trained in the usage, installation, operation,
and maintenance of the circuit breaker shall
be allowed to work on this equipment. It
is mandatory that this instruction bulletin,
any supplements, and service advisories be
studied, understood, and followed.
2. Maintenance programs must be consistent
with both customer experience and
manufacturer’s recommendations,
including service advisories and instruction
bulletin(s). A well planned and executed
routine maintenance program is essential
for the circuit breaker’s reliability and safety.
3. Service conditions and circuit breaker
applications shall also be considered in the
development of safety programs. Variables
include ambient temperature; humidity;
actual continuous current; thermal cycling;
number of operations; interrupting duty;
and any adverse local conditions including
excessive dust, ash, corrosive atmosphere,
vermin and insect infestations.
D. Specific
1. DO NOT WORK ON AN ENERGIZED
CIRCUIT BREAKER. If work must be
performed on a circuit breaker, remove it
from service and remove it from the
metal-clad switchgear.
2. DO NOT WORK ON A CIRCUIT BREAKER
WITH THE CONTROL CIRCUIT ENERGIZED.
4
3. EXTREME CARE MUST BE EXERCISED
TO KEEP ALL PERSONNEL, TOOLS, AND
OTHER OBJECTS CLEAR OF MECHANISMS
WHICH ARE TO BE OPERATED,
DISCHARGED, OR RELEASED. These
circuit breakers utilize stored energy
mechanisms. These mechanisms must be
serviced only by skilled and knowledgeable
personnel capable of releasing each spring
load in a controlled manner. Detailed
information regarding these mechanisms is
found in this instruction bulletin.
4. DO NOT ATTEMPT TO CLOSE THE CIRCUIT
BREAKER MANUALLY ON AN ENERGIZED
CIRCUIT.
5. DO NOT USE AN OPEN CIRCUIT BREAKER
AS THE SOLE MEANS OF ISOLATING A
HIGH VOLTAGE CIRCUIT. For complete
isolation, the circuit breaker shall be in
the disconnected position or shall be
withdrawn completely.
6. ALL COMPONENTS SHALL BE
DISCONNECTED BY MEANS OF A VISIBLE
BREAK AND SECURELY GROUNDED FOR
SAFETY OF PERSONNEL PERFORMING
MAINTENANCE OPERATIONS ON THE
CIRCUIT BREAKERS.
7. Interlocks are provided to ensure the
proper operating sequences of the circuit
breakers and for the safety of the user. If for
any reason an interlock does not function
as described, do not make any adjustments,
modification, or deform the parts. DO
NOT FORCE THE PARTS INTO POSITION.
CONTACT POWELL FOR INSTRUCTIONS.
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Safety
01.4IB.65120
E. X-Rays
F. Safety Labels
When high voltage is applied across the
contacts of a vacuum interrupter, there is the
possibility of generation of X-rays. The intensity
of the X-radiation is dependent on the peak
voltage and the contact gap. At the normal
operating voltage for this type of equipment,
the radiation levels are negligible. At the
voltages specified for testing, test personnel
shall be in front of the circuit breaker such that
the two layers of steel used in the frame and
front cover construction are between the test
personnel and the vacuum interrupters, and
that the test personnel be no closer than one
meter (3’) from the front of the circuit breaker.
THE CIRCUIT BREAKER SHALL BE EITHER
FULLY OPEN, OR FULLY CLOSED WHEN
MAKING HIGH POTENTIAL TESTS. DO NOT
TEST WITH CONTACTS PARTIALLY OPEN.
Safety
The equipment described in this document
has DANGER, WARNING, CAUTION, and
instruction labels attached to various locations.
All equipment DANGER, WARNING, CAUTION,
and instruction labels shall be observed when
the circuit breaker is handled, operated, or
maintained.
NOTICE
Warning and Caution labels are located in
various places in and on the switchgear and
on the circuit breaker removable element.
Always observe these warnings and caution
labels. Do NOT remove or deface any of these
warning/caution labels.
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PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
Ch 3 Equipment Description
B. The Stored Energy Mechanism
1) Mechanical Description
A. General
The PowlVac 38™ ARM vacuum circuit breakers
(Figure 1) use sealed vacuum interrupters
(Figure 2, f ) to control the primary circuit.
Primary connections to the associated
metal-clad switchgear are made by tubular
busbars terminating in the finger clusters
of the primary disconnecting devices
(Figure 2, a & g). The primary disconnecting
devices, busbars, and vacuum interrupter
assemblies are supported by high voltage
insulators (Figure 2, i) specifically designed for
the application.
The primary current path side of the circuit
breaker is considered the rear of the circuit
breaker, while the side with the cover
containing the various indicators and
manual operators is considered the front of
the circuit breaker. By removing the front
cover, the operating mechanism of the
circuit breaker is exposed. The stored energy
mechanism assembly provides motion to
each of the vacuum interrupters moving
contact assemblies through contact operating
pushrods. In the same metal enclosed
compartment as the stored energy mechanism
is the circuit breaker racking mechanism and
interlocks which control the movement of the
circuit breaker between the test/disconnected
and connected positions. The racking
mechanism provides the motion to
engage/disengage the primary disconnecting
devices and to open/close the shutters in
metal-clad switchgear.
6
The stored energy mechanism is located in
the front of the circuit breaker behind the
front cover. The front cover is held in place
with cover bolts (9) (Figure 1, g). The bolts
may be removed to allow access to the
stored energy mechanism and its interlocks,
auxiliary switches, and other control
devices.
!
CAUTION
Prior to removing the front cover, the user
must make sure the circuit breaker is in the
OPEN position and the main closing spring is
fully discharged. Failure to do so may result in
injury.
On the escutcheon plate of the stored
energy mechanism, there are two (2)
indicators that show the various states
of operation of the mechanism and two
(2) manual operators that will open/close
the stored energy mechanism. The circuit
breaker nameplate (Figure 1, f ) is also
located on the mechanism escutcheon. If
for any reason the escutcheon is removed
from the circuit breaker, it shall be verified
that the serial number contained on the
nameplate matches the engraved serial
number plate (Figure 2, m) permanently
affixed to the rear of the circuit breaker
frame prior to installing the escutcheon.
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Equipment Description
01.4IB.65120
Figure 1
Front View of PowlVac 38™ ARM
Circuit Breaker with Cover
a
b
c
d
e
f
g
h
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m
n
p
q
r
o
a.Handle
b. Emergency Racking Drive Shaft Shutter
c. Breaker Position Indicator
d. Interlock Window Assembly
e. Front Cover
f.Nameplate
g. Cover Bolt (9)
h. TOC Actuator
i. Manual Trip Operator
Equipment Description
j. MOC Actuator
k. Manual Charging Crank
l. Circuit Breaker Open/Closed Indicator
m. Secondary Disconnect Receptacle
n. Manual Close Operator
o. Operations Counter
p. Secondary Disconnect Receptacle Guide
q. Spring Charge Indicator
r. Anti-Rollout Latch
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PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
Figure 2
Rear View of PowlVac 38™ ARM
Circuit Breaker
a
b
c
d
e
f
g
h
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k
l
m
n
o
a. Upper Primary Disconnecting Device (3)
b. Lifting Points (2)
c. Crank Arm Roller
d. Racking Crank Arm
e. Racking Shaft
f. Vacuum Interrupter (3)
g. Lower Primary Disconnecting Device (3)
h. TOC Switch Actuator
i. High Voltage Insulator (3)
j. Jackshaft Pin
k. Operating Pushrod (3)
l. Main Shaft Pin
m. Engraved Serial Number Plate
n. Interference Plate
o.Wheel
8
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Equipment Description
01.4IB.65120
Figure 3
Operating Pushrod Assembly of
PowlVac 38™ ARM Circuit Breaker
Figure 4
Ground Connection of
PowlVac 38™ ARM Circuit Breaker
Equipment Description
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PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
The mechanism employed in the circuit
breaker is a stored energy system which
uses a charging motor to compress the
main closing spring. The energy stored in
the main closing spring is released during
the closing operation. The released energy
allows the mechanism to close the vacuum
interrupter contacts, compress the contact
loading springs, charge the opening
springs, and overcome frictional forces.
When the circuit breaker is opened, the
energy stored in the opening and contact
loading springs is released, and the vacuum
interrupter contacts are opened.
The charging motor (Figure 5, j), located
on the bottom right of the base pan, is
assembled to the circuit breaker by a
bracket that is bolted to the base pan. The
charging motor drive shaft inserts into the
eccentric drive shaft. The eccentric drive
shaft is supported by needle roller bearings
in the mechanism frame side sheets and
transmits the motor torque to the left side
of the mechanism.
When the charging motor is energized, the
eccentric drive shaft rotates and causes
the pawl support arms to pivot about the
camshaft (Figure 6, p). The drive pawl
(Figure 6, m), which is supported by the
arms, engages with the ratchet wheel and
drives the ratchet wheel one tooth at a
time. To prevent backwards motion of the
ratchet wheel, a spring-loaded holding
pawl is used to latch the ratchet wheel after
each advance from the drive pawl.
10
To ensure correct synchronization of the
drive and holding pawl, the position of the
holding pawl support arms are adjusted by
the holding pawl adjusting eccentric
(Figure 6, f ), located at the left front of
the mechanism. When the mechanism is
operated manually, the top pawl becomes
the drive pawl and the bottom pawl
becomes the holding pawl.
The ratchet wheel (Figure 6, i) has
projections from its side faces which
engage the drive plates as it rotates. These
drive plates are attached to the camshaft,
thus causing the camshaft to rotate. Crank
arms (Figure 6, h) are attached to the ends
of the camshaft. Crank pins (Figure 6, g)
are assembled to the crank arms, which
point outward. The crank arms engage
the bottom ends of the connecting rods
(Figure 5, e). The pins that project from
the spring yoke, which straddles the main
closing spring, engage the top ends of the
connecting rods. As the camshaft rotates
the connecting rods pull the spring yoke
downward, compressing the main closing
spring.
The ratchet wheel drives the camshaft so
that the connecting rods go down to their
lowest position, and then start to move
upward. At a certain point, the spring force
overcomes friction and resistance and starts
to rotate the camshaft. At the same time,
the pawls are uncoupled from the ratchet
wheel by the pawl lift drive plate
(Figure 6, j), and the motor cutoff switch
is operated. The motor cutoff switch
(Figure 6, t), located to the right of the
mechanism, is operated by the spring
charge indicator and motor cutoff cam
(Figure 6, q). The spring charge indicator
(Figure 1, q) displays that the mechanism is
charged.
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Equipment Description
01.4IB.65120
Figure 5
Front View of PowlVac 38™ ARM
Circuit Breaker without Cover
a
b
c
d
e
f
g
h
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j
a.
b.
c.
d.
e.
f.
g.
h.
i.
j.
Equipment Description
Opening Spring
Anti-Pump Relay
Emergency Racking Drive Shaft Shutter
Main Closing Spring
Connecting Rod
Racking Motor
Opening Anti-Bellows Spring
Shock Absorber
Auxiliary Switch
Charging Motor
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PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
Figure 6
Close-Up Front View of PowlVac 38™ ARM
Circuit Breaker Mechanism
a
b
c
d
e
g
f
h
j
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k
p
q
r
s
m
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w
x
a. Primary Shunt Trip Coil
b. Secondary Trip Prop Adjusting
Screw
c. Latch Check Switch Operator
d. Holding Pawl Support Arm
e.Jackshaft
f. Holding Pawl Adjusting Eccentric
g. Crank Pin
h. Crank Arm
i. Ratchet Wheel
j. Pawl Lift Drive Plate
k. Close Latch Arm
l. Close Latch Shaft
12
m. Drive Pawl
n. Pawl Support Arm
o. Closing Coil
p.Camshaft
q. Motor Cutoff Cam
r. Close Bar Adjusting Screw
s. Charging Motor Drive Shaft
t. Motor Cutoff Switch
u. Secondary Trip Prop
v. Main Cam Roller
w. Reset Spring
x. Main Closing Cam
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Equipment Description
01.4IB.65120
Figure 7
Cam and Fundamental Linkage Positions
a) Breaker Open - Spring Charged - Links Reset
c) Breaker Open - Spring Discharged
Equipment Description
b) Breaker Closed - Spring Discharged
d) Breaker Closed - Spring Charged
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13
PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
Figure 8
Mechanical and Trip Linkages
a
m
k
b
l
c
e
f
j
d
g
i
h
a. Secondary Trip Prop Adjusting Screw
b. Secondary Trip Prop Shaft
c. Secondary Trip Prop
d. Secondary Linkage Roller
e. Main Cam Roller
f. Reset Spring
g.Camshaft
h. Main Closing Cam
i. Center Phase Operating Lever
j.Jackshaft
k. Primary Trip Prop Roller
l. Primary Trip Prop Adjusting Screw
m. Primary Trip Prop
14
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Equipment Description
01.4IB.65120
The camshaft (Figure 6, p) is restrained
by the close latch arm engaging against
the close latch shaft. The main closing
cam, located between the mechanism
side sheets, is in a position where the
fundamental linkage can move to the reset
position.
The close latch shaft, when released either
by the closing coil or the manual close
operator, allows the main closing spring to
pull the crank arms upward. As the crank
arm moves upward it rotates the main
closing cam and drives the fundamental
linkage into the closed position. This action
causes the main linkage to rotate the
jackshaft to drive the operating pushrod
(Figure 3) toward the current carrying side
of the circuit breaker.
Each operating pushrod assembly
(Figure 2, k) encloses a contact loading
spring. At the end of this spring is a
pivot block. The pivot block is restrained
by a lock nut on a stud which passes
through the contact loading spring and
is attached to the operating pushrod
assembly. The contact loading spring has
initial compression such that as soon as
the vacuum interrupter contacts touch,
the springs are preloaded to a value
sufficient to resist vacuum interrupter
contact separation under the highest
electromagnetic forces exerted by the rated
short circuit current. Further movement
of the operating pushrod assembly
compresses the contact loading spring and
produces a gap between the face of the
pivot block and the lock nut. This
nut-gap is used to evaluate the erosion of
the vacuum interrupter contactors.
Equipment Description
In the closing cam and fundamental
linkage positions shown in
(Figure 7, b & d), the contact loading
springs and the main opening springs are
both acting to compress the three (3) main
mechanism links. The jackshaft extends
from the left to the right side of the circuit
breaker frame and is supported at the main
circuit breaker frame side sheets and by
the mechanism. The outer operating levers
on the jackshaft have connections to the
circuit breaker opening springs
(Figure 5, a & g).
The fundamental linkage is restrained from
movement by the secondary trip prop
(Figure 8, c) acting on the primary trip
prop roller (Figure 8, k). A component of
force tends to make the primary trip prop
rotate upward, but it is restrained by the
secondary trip prop face acting on the
primary trip prop roller. The clearance
between the primary trip prop roller and
the secondary trip prop is controlled by the
primary trip prop adjusting screw
(Figure 8, l). When the trip shaft is rotated
by the action of the manual trip operator or
the primary shunt trip coil, the secondary
trip prop face moves downward and
permits the primary trip prop to rotate
upward, thus permitting the main linkage
to move upward and the jackshaft to rotate,
opening the circuit breaker. The jackshaft
levers engage the shock absorber
(Figure 5, h), which controls the rebound
of the vacuum interrupter contacts on an
opening operation.
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15
PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
With the standard electrical control
scheme, as soon as the main closing spring
is discharged on a closing operation, the
charging motor is switched on to recharge
the springs. This leaves the main closing
cam in a position where a tripped linkage
can reset under the action of the reset
spring (Figure 6, w) and the primary and
secondary trip props can move into the
reset position. The reset spring stretches
between an extension of the main cam
roller pin and a spring support pin located
on the left mechanism side sheet. The latch
check switch, operated by a lever on the
trip shaft, will close as the secondary trip
prop reaches the fully reset position.
2) Electrical Description
a. Charging Motor
The function of the charging motor
(Figure 5, j) is to compress the main
closing spring of the stored energy
mechanism, thus providing the
necessary energy to close the circuit
breaker. The charging motor, located
at the bottom right of the base pan is
assembled to the circuit breaker by a
bracket that is bolted to the base pan.
b. Motor Cutoff Switch
The motor cutoff switch (Figure 6, t)
provides an electrical break
in the control circuit that supplies
the charging motor when the main
closing spring is fully charged and the
stored energy mechanism is ready
for a closing operation. The motor
cutoff switch is located at the bottom
right side of the mechanism, and is
supported by a bracket which is bolted
to the circuit breaker base pan.
16
c. Anti-Pump Relay
The anti-pump relay (Figure 5, b)
provides a logic function for the control
circuit which prevents a continuous
electrical close signal from causing the
circuit breaker to continuously reclose
after a trip signal. The anti-pump relay
is located on the circuit breaker frame,
to the left of the connecting rod, and is
supported by two screws.
d. Operating Solenoids
Electrical operation of the circuit
breaker is accomplished using
operating solenoids.
The closing coil (Figure 6, o) is an
operating solenoid located at the
bottom center of the mechanism and
is assembled to the circuit breaker
base pan by bolts accessible from
underneath circuit breaker.
The primary shunt trip coil
(Figure 6, a) is located at the top left
side of the mechanism and is
assembled to the lower frame channel
by two bolts.
Either a secondary shunt trip coil
assembly or an undervoltage device
may be furnished as an option. When
furnished, either of these devices are
located to the top right side of the
mechanism and is supported from
the lower frame channel. Only one of
these two operating solenoids may be
furnished on any one circuit breaker, as
both devices are located in the same
space.
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Equipment Description
01.4IB.65120
Figure 9
Operation Sequence
Secondary
Disconnect
Makes
Motor “M”
Energized
Green Light
Energized
Close Spring
Charged
LS
Makes
LS
Breaks
LS
Breaks
LS
Makes
White Light
Energized
Motor “M”
Deenergized
“Y” Circuit
Disabled
LCS
Makes
Close Control
“CS/C” Makes
Close Coil “CC”
Energized
Close Spring
Discharged
LS
Breaks
LS
Makes
LS
Breaks
LS
Makes
52/b
Breaks
White Light
Deenergized
Motor “M”
Energized
Prevents
Close Coil
Energization
Before
Spring is
Fully Charged
“Y” Coil
Energized
Close Coil “CC”
Deenergized
Close Spring
Charged
“Y” Contact
Makes
“Y” Coil
“Seals In”
LS
Makes
LS
Breaks
White Light
Energized
Motor “M”
Deenergized
LS
Breaks
LS
Makes
VCB Closed
52/b
Breaks
52/a
Makes
Green Light
Deenergized
Trip Circuit
Set Up
Red Light
Energized
Release Close
Control Switch
“CS/C” Breaks
“Y” Coil
Deenergized
“Y” Contact
Breaks
Prevents
Pumping
if VCB Trips
Before Control
Switch is
Released
Equipment Description
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17
PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
Typical Control Scheme
Close
11
12
18
13
J
E
5
6
7
LS
15
LS
1
52
b
A
1
12
Y 125VDC CC 125VDC
B
2
K
M 125VDC/120VAC
1
TC 125VDC
2
LS
10
17
Device Cross Reference Tables
112A
104E
109E
115E
105F
111E
109F
115E
111F
115B
115F
6
115F
7
111F
NO C NC
105F
108C
8
CP
115A
104D
109F
109F
12 11 10 9
LCS
105F
104A
104C
111F
104C
115F
24 23 22 21 20 19 18 17 16 15 14 13
105B
1
CP
105E
2
EF
110C
9 M1
5 4
12 K
113C
11 J
3
SD
CP
17
7
5
21
8
8
23
52 16
b 18
52
a
16
20
22
24
14
10
17
LS
19
6
14
2
15
C1
8
M1
M1
13
11
52
52
52
b 14 a 12 b
4
15
9
2
52
a
F
F
10
3
52
a 4
Pins Not Used
NC
E
NO
To Rated
Control Power
9
6
18
C
LCS
12
To Rated
Control Power
2
52
a
Pins Not Used
1
4
1
Y1
9
To Rated
Control Power
7
19
4
2
Y
3
1
7
LS
J
J
5
T
11
3
13
11
1
20
9
Trip
16
Figure 10
Device IDs
LS = Spring Charge Limit Switch (Shown w/ Spring Discharged)
LCS = Latch Check Switch (Shown w/ Spring Discharged)
Y = Anti-Pump Relay
TC = Breaker Trip Coil
CC = Breaker Close Coil
M = Charging Motor
52/a = Breaker Auxiliary Contact (Normally Open)
52/b = Breaker Auxiliary Contact (Normally Closed)
SD = Breaker Secondary Disconnect
TB = Terminal Block
Y
471
CP
693
105C
52
18
(Front View)
CP
12
56
9 10
13 14
16 18
109E
78
106E
11 12
106F
15 17
113F
CP
106E
34
106F
112C
106F
113E
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Equipment Description
01.4IB.65120
e. Control Circuit
The typical AC & DC electrical control
schemes are shown in Figure 10.
The control scheme of any particular
circuit breaker may differ depending
on the user’s requirements, operating
solenoids, and the control devices
furnished with that circuit breaker.
The sequence of operation for all
control schemes is shown in
Figure 9. Circuit breaker mounted
auxiliary contacts not used in the
control circuit are brought out for
control and indication functions. The
metal-clad switchgear equipment
may provide a circuit breaker MOC
(Mechanism Operated Cell Switch) for
additional contacts.
C. Automatic Racking Mechanism
1) General Description
The racking mechanism is the mechanical
assembly that facilitates moving the circuit
breaker between the breaker
test/disconnected and connected positions
in the circuit breaker compartment. The
main racking mechanism components
for the PowlVac 38™ ARM vacuum circuit
breaker are shown and described in the
following sections:
a. Breaker Position Indicator
The breaker position indicator
(Figure 1, c) is visible through an
opening in the circuit breaker front
cover. The indicator displays whether
the circuit breaker is in the connected
or the test/disconnected positions.
When the breaker position indicator
displays “BREAKER CONNECTED”,
and this is fully visible in the aperture,
the circuit breaker is in the connected
Equipment Description
position. When the breaker position
indicator displays “BREAKER TEST/
DISCONNECTED”, and this is fully visible
in the aperture, the circuit breaker is in
the test/disconnected position. In
positions other than the connected and
test/disconnected positions, the breaker
position indicator does not display an
indication. Refer to Ch 4 Installation,
E. Inserting the Circuit Breaker into the
Circuit Breaker Compartment for more
information.
b.Interlocking
PowlVac 38 circuit breakers are provided
with several interlocks that operate in
conjunction with the circuit breaker
compartment to ensure the proper
operation of the circuit breaker. Do
not attempt to modify or bypass these
interlocks, as they are necessary for the
safe operation of the circuit breaker.
The purpose of the interlocks is to
ensure:
•
•
•
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The circuit breaker cannot be moved
from the test/disconnected to the
connected position unless the main
circuit breaker contacts are opened
and the secondary control circuitry
from the compartment to the circuit
breaker is completed. Also, the
circuit breaker cannot be removed
from the connected to the
test/disconnected position unless
the main contacts are opened.
The control circuits cannot be
broken when the circuit breaker is in
the connected position.
The circuit breaker cannot be
removed from the circuit breaker
compartment with the circuit
breaker closed or with the main
closing spring charged.
19
PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
The PowlVac 38™ ARM circuit breaker
interlocking is primarily achieved by
means of an interlock bar attached to
the secondary disconnect plug and
tripping linkage and roller. Upon initial
insertion of the circuit breaker into
the compartment, a position interlock
prevents moving the circuit breaker
from the disconnected position to the
test position without the secondary
disconnect inserted. This interlock is
located under the frame of the circuit
breaker on the right side beneath the
secondary disconnect receptacle and
contacts a stop in the compartment.
When the secondary disconnect plug
is connected to the circuit breaker,
the position interlock bar and roller is
lifted to allow the circuit breaker to be
moved into the test position. During
the action of moving the breaker from
the disconnected position to the test
position the interlock roller is further
lifted by a cam that is mounted in the
circuit breaker compartment. This
movement actuates a latch which
engages the secondary disconnect
interlock bar. The latch prevents
removing the secondary disconnect
plug from the circuit breaker in any
position except the disconnected
position.
The tripping linkage and roller
under the breaker frame follow a
cam mounted in the circuit breaker
compartment. The cam, in all
intermediate positions between the
test/disconnected and connected
position, lifts the tripping roller. Lifting
the tripping roller actuates the manual
trip operator which holds the breaker
in a trip free condition. The manual trip
operator also actuates the latch check
switch, thus blocking any electrical
closing signal.
20
c. Blocking Interlock
Access to the emergency racking drive
is controlled by a blocking interlock.
The interlocks ensure that the circuit
breaker is open when it is manually
racked into the compartment. Once the
circuit breaker reaches the operating
position the circuit breaker can be
closed.
2) Racking Mechanism
The racking mechanism consists of a
racking shaft (Figure 2, e) with racking
crank arms (Figure 2, d) at each end, which
are supported by the frame side sheets.
The racking motor (Figure 5, f ) is located
at the left end of the racking shaft, inside
the circuit breaker frame. In addition, the
racking crank arms have rollers attached to
each end of the racking shaft which engage
the vertical slots of the racking cams in the
circuit breaker compartment. Rotation
of the racking crank arms will drive the
circuit breaker into or out of the connected
position. This action also operates the
compartment shutters.
Electrical sensors control the stopping
position of the circuit breaker. The
sensors are located in the circuit breaker
compartment.
Bolts on the left and right side sheets
provide a backup mechanical stop to the
crank arms. This positive stop prevents
further rotation of the racking shaft, thus
stopping circuit breaker travel. At this time,
the breaker position indicator on the front
of the circuit breaker will display
“BREAKER CONNECTED”.
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Equipment Description
01.4IB.65120
D.Circuit Breaker Compartment Interfaces
1) Primary Disconnecting Devices
There are six primary disconnecting devices
(Figure 2, a & g) on the circuit breaker. They
are arranged, two per phase, with the upper
device connected to the stationary end
of the vacuum interrupter, and the lower
device connected to the moving end of the
vacuum interrupter assembly.
Each primary disconnecting device
has multiple contact fingers which
will mate with the stationary primary
disconnecting devices in the circuit breaker
compartment.
!
CAUTION
Do NOT handle or move the circuit breaker by
the primary disconnecting devices, as damage
may occur.
2) Secondary Disconnecting Devices
Control power is transferred from the
metal-clad switchgear to the circuit breaker
by means of the secondary disconnecting
devices. The secondary disconnect
receptacle (Figure 1, m) is located on the
bottom right side of the circuit breaker.
The secondary disconnect plug is attached
to the switchgear and is located on the
right side wall of the circuit breaker
compartment. This arrangement allows the
secondary connection to be visible in all
positions of the circuit breaker.
Equipment Description
3) MOC (Mechanism Operated Cell Switch)
Actuator
The mechanism operated cell switch
(MOC), located in the switchgear, is an
auxiliary switch operated by a lever which
extends from the circuit breaker operating
mechanism. Movement of the MOC
actuator (Figure 1, j) is directly related
to the movement of the circuit breaker
mechanism and contacts.
4) TOC (Truck Operated Cell Switch) Actuator
The truck operated cell switch (TOC),
located in the switchgear, is operated by
the circuit breaker truck position.
To accomplish this, a TOC actuator
(Figure 1, h) is located on the middle, right
side of the circuit breaker frame and it is
designed to strike the TOC as the circuit
breaker travels to the connected position.
5) Ground Connection
The ground connection (Figure 4) is an
assembly of spring loaded fingers that
grounds the circuit breaker frame as it
is inserted into the compartment. The
ground connection is located on the
bottom side of the frame between the
B and C phases. An extension of the
metal-clad switchgear ground bus is
secured to the circuit breaker compartment
floor and engages the ground connection
as the circuit breaker is placed into the
disconnected position. The ground
connection system remains engaged in all
subsequent positions of the circuit breaker
until the circuit breaker is removed from the
compartment.
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21
PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
6) Anti-Rollout Latch
The circuit breaker is equipped with an
anti-rollout latch (Figure 1, r) which
prevents inadvertent removal of the
circuit breaker from the compartment by
engaging a tab in the compartment.
E. Vacuum Interrupters
For a listing of the vacuum interrupters used
in Type ARM circuit breakers, see Table E,
Primary Current Path. A label which shows
the part number is attached to each vacuum
interrupter. Replacement vacuum interrupters
must have the same part number as the
original vacuum interrupter.
F. Vacuum Interrupter Connections
The top stem of the vacuum interrupter utilizes
a pad that is bolted to the upper primary
assembly (Figure 21, #32). The lower vacuum
interrupter stem has a copper block threaded
onto it and is the movable end of the assembly
(Figure 21, #3). Fastened to the copper block is
a flexible copper shunt (Figure 21, #19) that is
attached to a stationary lower bus connector
(Figure 21, #11). An electrostatic shield
which covers the shunt and another primary
disconnecting device is attached to the lower
bus connector.
22
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Equipment Description
01.4IB.65120
Ch 4 Installation
Figure 11
Circuit Breaker in Shipping Carton
A. Receiving
When the circuit breaker is received, check
for signs of damage. If damage is found or
suspected, file claims as soon as possible with
the transportation company and notify the
nearest Powell representative.
Estimated size and weight for shipping a
PowlVac 38™ ARM circuit breaker on a pallet:
•
•
Size: 42” width x 42” depth x 47” height
Weight: 750 lbs.
Figure 11 shows the circuit breaker enclosed
in the carton used for shipment. The carton is
attached to the shipping pallet by two metal
bands. Remove these bands and lift the carton
from the pallet so that the circuit breaker is
visible. The circuit breaker is attached to the
pallet by three metal shipping brackets. When
these are removed the circuit breaker may
be removed from the shipping pallet. Refer
to Ch 4 Installation, B. Handling, for more
information.
When a metal-clad switchgear assembly is
installed in a Power Control Room, a circuit
breaker housed in the lower circuit breaker
compartment may be shipped installed in the
equipment. In these cases, the circuit breaker
will be in the test/disconnect position and it
will be bolted to the compartment floor by use
of a shipping bracket. The horizontal leg of
the bracket is bolted to the compartment floor
and the vertical leg is bolted to the front of
the circuit breaker using the lower cover bolts.
Remove these four bolts, discard the shipping
angle, and replace the four bolts.
Installation
B. Handling
After the circuit breaker has been removed
from its shipping pallet it may be rolled on
its own wheels on a level surface. This is the
preferred way of handling the circuit breaker.
When rolling the circuit breaker, it should be
pushed and steered by the steel frame or the
front cover.
!
CAUTION
Do NOT handle or move the circuit breaker
by the primary disconnecting devices, as
damage may occur.
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23
PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
If necessary, the circuit breaker can be moved
by a lift truck or an overhead crane. When
using the lift truck, load the circuit breaker
front first onto the lift and ensure that it is
secured to the lift truck. The circuit breaker
can also be lifted by an overhead crane using
the two lifting points (Figure 12) which have
been provided for hooks at the top of the
circuit breaker frame side sheets. The circuit
breaker will tilt backward when it is lifted by
a crane. Therefore, when setting down the
circuit breaker, it will be necessary to guide the
circuit breaker to ensure that all four wheels are
placed on a level surface. Use the front handles
or top front frame to guide the circuit breaker
to an upright position on a level surface.
Figure 12
Lifting the Circuit Breaker by Crane
Note: PowlVac 38 CDS circuit breaker
shown.
C. Storage
Shipping and storage of electrical equipment
requires measures to prevent the deterioration
of the apparatus over a long unused period.
The mechanical and dielectric integrity must be
protected. Electrical equipment is designed for
use in a variety of environments.
24
When the equipment is in transit and storage,
these design considerations are not fully
functional. In general, the following measures
must be considered.
1. Equipment designed for indoor installation
must be stored indoors in a climate
controlled environment to prevent
condensation of moisture. Exposure to rain
and the elements, even for a short period,
can permanently damage the equipment.
Space heaters within the equipment should
be energized, if so equipped. Humidity
controlling desiccant materials should
be utilized when space heaters are not
provided or cannot be energized. The
temperature should be kept above 33°F/1°C
and below 140°F/60°C. The relative
humidity should be kept below 60% or a
dew point of 15°C/59°F. The equipment
should be stored in such a manner as
to leave all doors and panels accessible
for inspection. The equipment must be
inspected on a routine basis to assure
operational integrity.
2. Equipment designed for outdoor exposure
may be stored either in indoor or outdoor
storage locations. The equipment must
be protected from airborne external
contaminates if stored outdoors. Outdoor
storage will also require additional care
to maintain temporary covers over
the openings and shipping splits. The
equipment must be provided with control
power to facilitate the energization of
space heaters, as well as other temperature
and humidity controlling equipment. The
temperature should be kept above freezing
(>33°F/1°C) and below (<140°F/60°C). The
relative humidity should be kept below
60% or a dew point of 15°C/59°F. The
equipment should be stored in such a
manner as to leave all doors and panels
accessible for inspection. The equipment
must be inspected on a routine basis to
assure its integrity.
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Installation
01.4IB.65120
3. The auxiliary control devices, ship loose
material and protective relays must also
be protected. This includes items such as
battery chargers, UPS systems, lighting,
installation hardware and air conditioning.
If prolonged storage is anticipated,
humidity controlling desiccant materials
should be utilized. Desiccant packets
should be installed in all compartments and
packing containers.
D.Placing the Circuit Breaker Into Service
Before shipment from our factory, all circuit
breaker functions are thoroughly checked. The
user must verify functions after receipt. Powell
recommends that the tests be performed in the
sequence listed below:
1) High Voltage Insulation Integrity
!
CAUTION
High voltages across the open gaps of the
vacuum interrupter can produce x-radiation.
When conducting high voltage test,
personnel should stand at least one meter (3’)
away from the circuit breaker with the covers
in place. Test voltages should not exceed
60kVAC (85kVDC) for the 38kV rated circuit
breaker.
If the DC high potential testing (HIPOT) is
required, the DC high potential test machine
must not produce instantaneous peak
voltages exceeding 85kV for the 38kV rated
circuit breaker.
The primary circuit insulation on the circuit
breaker may be checked phase-to-phase
and phase-to-ground using a 2500V
insulation resistance tester. Since definite
limits cannot be given for satisfactory
insulation values when testing with an
insulation resistance tester, a record should
be kept of the insulation resistance tester
Installation
readings as well as the temperature and
humidity readings. This record should
be used to detect any weakening of the
insulation system from one check period to
the next.
To check insulation integrity, the AC high
potential test described below is strongly
recommended. Using DC testing is not
the preferred method, however, values are
provided due to the availability of DC test
sets.
CAUTION
If DC high potential testing is performed,
the DC high potential test machine must
not produce instantaneous peak voltages
exceeding 85kV.
The circuit breaker insulation should be
tested with the circuit breaker vacuum
interrupter contacts in the CLOSED
position.
The racking mechanism should be operated
to place the racking arms in the “connected”
position (rotated to the front of the breaker,
away from the primary disconnecting
devices) prior to performing the dielectric
testing. It is necessary that a secondary
disconnect override device be used to
permit rotating the racking shaft. See
Ch 4 Installation, D. Placing the Circuit
Breaker Into Service, 4) Mechanical Operation
Check.
Test each pole of the circuit breaker
separately, with the other 2 poles and
the frame grounded. Perform the field
dielectric test described in ANSI Standard
C37.20.2, at the voltage level appropriate
for the equipment (Table A Field Dielectric
Test Values).
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25
PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
Table A Field Dielectric Test Values
Rated Maximum Voltage
(kV rms)
Power Frequency Withstand
(kV rms)
38
60
This test will have checked all of the
primary phase-to-ground and
phase-to-phase insulation.
!
CAUTION
After the high potential is removed, an
electrical charge may be retained by the
vacuum interrupters. Failure to discharge
this residual electrostatic charge could
result in an electrical shock. All six primary
disconnecting devices of the circuit breaker
should be grounded and remain grounded for
at least one minute to reduce this electrical
charge before coming into contact with the
primary circuit.
CAUTION
Remove all grounding conductors applied
for this test before placing the circuit breaker
back into service.
The tests described in this section are the
only tests required to ascertain insulation
integrity. Because of the design of the
PowlVac® insulation system, no valid data
can be obtained utilizing other types of
high voltage insulation tests.
2) Vacuum Integrity
!
CAUTION
Applying abnormally high voltages across a
pair of contacts in the vacuum, may produce
x-radiation. The radiation may increase with
increased voltage and/or decreased contact
spacing.
The x-radiation, produced during this test with
the voltage specified in Table A and normal
contact spacing, is extremely low and well
below the maximum permitted by standards.
Do NOT apply voltage that is higher than the
recommended value. Do NOT use contact
separation that is less than the normal open
position separation of the circuit breaker
contacts.
Powell recommends AC testing for reliable
verification of vacuum integrity. All
PowlVac 38™ ARM circuit breakers shall be
tested with a minimum of 40kVAC applied
directly across fully open contacts for 10
seconds. No dielectric breakdown during
the test period constitutes a successful test.
Note: The AC test does not replace the AC
high potential testing (Hipot) used to
determine “High voltage insulation
integrity.” For more details, see
Ch 4 Installation, D. Placing the
Circuit Breaker Into Service, 1) High
Voltage Insulation Integrity.
Powell offers a compact and lightweight
PowlVac Vacuum Integrity Tester
designed specifically for PowlVac circuit
breakers. If this device is used, refer to
the instruction bulletin provided with the
vacuum integrity tester.
26
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Installation
01.4IB.65120
Powell recognizes the widespread use
of DC hipot equipment in the field and
the desire to use this equipment to verify
vacuum integrity. However, the capacitive
component of the vacuum interrupter
during DC testing may yield false negative
test results, which are often misinterpreted
as vacuum interrupter failure. When DC
testing is performed, a test set providing
a full wave rectified 40kVDC hipot voltage
can be applied for 5 seconds as a
“go - no go” test.
Recording the leakage readings is not
necessary, as a dielectric breakdown will
trip all portable DC hipot test sets. If a
DC test breakdown occurs, the test must
be repeated after reversing the DC high
voltage test supply connection across the
vacuum interrupter. The working condition
of a vacuum interrupter should be
questioned only if it has failed both tests.
!
CAUTION
When testing with DC, use a DC high
potential test (HIPOT) set with FULL WAVE
rectification. Do NOT use half-wave
rectifiers. The capacitance of the vacuum
interrupter in combination with the leakage
currents in the rectifiers and its DC voltage
measuring equipment may result in applying
peak voltages as much as three times the
measured voltage. These abnormally high
voltages may give a false indication of a
defective vacuum interrupter, and may
produce abnormal x-radiation.
No attempt should be made to try to
compare the condition of one vacuum
interrupter with another, nor to correlate
the condition of any vacuum interrupter
with low values of DC leakage current.
There is no significant correlation.
!
CAUTION
After the high potential is removed, an
electrical charge may be retained by the
vacuum interrupters. Failure to discharge
this residual electrostatic charge could
result in an electrical shock. All six primary
disconnecting devices of the circuit breaker
should be grounded and remain grounded for
at least one minute to reduce this electrical
charge before coming into contact with the
primary circuit.
3) Control Voltage Insulation Integrity
If the user wishes to check the insulation
integrity of the control circuit, it may be
done with a 500V or 1000V insulation
resistance tester or with an AC high
potential tester. The AC high potential test
should be made at 1125V, 50Hz or 60Hz for
one minute. The charging motor must be
disconnected prior to testing the control
circuit. The charging motor itself may be
similarly tested at a voltage not to exceed
675V, 50Hz or 60 Hz. Be sure to remove any
test jumpers and reconnect the charging
motor after the tests are complete.
CAUTION
CAUTION
If DC high potential testing is performed,
the DC high potential test machine must
not produce instantaneous peak voltages
exceeding 85kV.
Installation
Remove all grounding conductors applied for
field dielectric test before placing the circuit
breaker back into service.
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27
PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
4) Mechanical Operation Check
5) Electrical Operation Check
The contacts of the vacuum interrupter
during normal operation cannot be closed
unless the secondary disconnect plug is
inserted into the secondary disconnect
receptacle. To check the circuit breaker
outside of the circuit breaker compartment,
it is necessary to simulate the connection
of secondary disconnecting device by
inserting the secondary disconnect
override device in the secondary
disconnect receptacle. This device must be
removed after testing and before the circuit
breaker is inserted into the compartment.
The mechanical operation of the circuit
breaker is checked by inserting the manual
charging handle into the manual charging
crank and pushing down until a metallic
click is heard. (This indicates that the
holding pawl has dropped into place on
the ratchet wheel). Lift the handle until it is
horizontal and then depress. The procedure
is repeated until the spring charge indicator
indicates “CLOSING SPRING CHARGED”. This
requires about 60 operations of the handle.
Remove the handle.
!
CAUTION
Care must be exercised to keep personnel,
tools, and other objects clear of mechanism
which are to be operated or released.
Push the manual close operator
(Figure 1, n) inward and the circuit breaker
will close. The circuit breaker open/closed
indicator (Figure 1, l), located above the
manual close operator will now display,
“Breaker Closed”. Push the manual trip
operator (Figure 1, i) inward, which is
located at the top of the escutcheon and
the circuit breaker open/closed indicator
will now display “Breaker Open”.
28
To check the basic electrical operation
of the circuit breaker, a circuit breaker
test cabinet should be used. Connect
the secondary disconnect from the
test cabinet to the circuit breaker to be
tested. The test cabinet provides control
voltage via a secondary disconnect plug
to the circuit breaker and the appropriate
control switches to verify the close and
open functions of the circuit breaker.
Specialized versions of the test cabinet
may also contain circuits for dual shunt
trip coils, undervoltage devices, or other
options. With the secondary disconnect
plug installed in the circuit breaker under
test, operate the power switch on the
test cabinet. The charging motor will
automatically charge the stored energy
mechanism’s main closing springs.
Operation of the control switch on the front
door of the test cabinet to the “CLOSE”
position will cause the circuit breaker to
close.
!
CAUTION
The MOC actuator is exposed when the circuit
breaker is outside the metal-clad switchgear
and can cause serious injury if the test
personnel or any object is in its travel path
during operation. Caution should be taken to
isolate the MOC side of the circuit breaker for
these tests.
The circuitry is arranged to cause the
charging motor to operate again and
charge the main closing spring. Operating
the control switch on the front door of the
test cabinet to the “OPEN” position will
cause the circuit breaker to open.
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Installation
01.4IB.65120
An alternate method for the electrical
operation check is to use a test jumper
cable to electrically operate the circuit
breaker using the control circuitry of
the circuit breaker compartment. If this
method is used, ensure that the operation
of the control circuitry of the compartment
being used for testing does not cause
undesirable effects or unintended
operation of other interconnected
equipment such as supervisory controls,
SCADA, or automatic transfer schemes.
First, remove the control fuses in the
compartment. Connect the jumper
cable to the secondary disconnect plug
in the compartment and to the circuit
breaker. Insert the fuses. The charging
motor will automatically charge the
stored energy mechanism’s main closing
springs. Operation of the breaker control
switch to “CLOSE”, on the front door of the
compartment, will cause the circuit breaker
to close. The circuitry is arranged to cause
the charging motor to operate again and
charge the main closing spring. Operating
the breaker control switch to “TRIP”, on the
front door of the compartment, will cause
the circuit breaker to open.
6) Emergency Racking Mechanism Check
The emergency racking mechanism may
be checked outside the circuit breaker
compartment.
The emergency racking drive shaft can be
accessed by moving the emergency racking
drive shaft shutter (Figure 5, c) downward.
Insert the racking handle onto the racking
drive shaft. The racking crank arms at the
sides of the circuit breaker should be in the
fully withdrawn position and point towards
the primary disconnecting devices.
The breaker position indicator on the front
of the circuit breaker should display,
“BREAKER TEST/DISCONNECTED”. Rotate
the racking handle in a counterclockwise
direction. The racking crank arms will move
downward and rotate until the
breaker position indicator displays
“BREAKER CONNECTED”. Stop bolts
on the side sheet of the circuit breaker
prevent further rotation of the racking
drive shaft. Once the breaker position
displays “BREAKER CONNECTED”, the
racking mechanism will have reached the
end of its travel and a significant increase
in the amount of resistance encountered
will indicate that further force should not
be exerted. Once factory torque limits are
reached a torque limiting clutch on the
racking handle will engage and disallow
any further racking. In this position, the
racking handle may be removed from the
racking drive shaft and the racking drive
shaft shutter will spring back to the closed
position.
Once again, depress the racking drive shaft
shutter, insert the racking handle onto the
racking drive shaft and rotate in a clockwise
direction until the racking crank arms are
once more in the fully withdrawn position
and the breaker position indicator displays
“BREAKER TEST/DISCONNECTED”.
Note: The emergency racking drive shaft
shutter cannot be moved downward
unless the secondary disconnect is
engaged and the main contacts are
OPEN.
Installation
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29
PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
E. Inserting the Circuit Breaker Into the Circuit
Breaker Compartment
Refer to the metal-clad switchgear instruction
bulletin and drawings produced specifically
for the installed equipment for additional
information and cautions before attempting
to insert the circuit breaker into the metal-clad
switchgear equipment.
NOTICE
Be sure that the racking crank arms at the
sides of the circuit breaker point in the
direction of the primary disconnecting devices
and the circuit breaker position indicator
displays breaker test/disconnected before
attempting to insert the circuit breaker into
the compartment.
Each circuit breaker and circuit breaker
compartment is provided with interference
plates which are designed to ensure that
no circuit breaker without the required
voltage, continuous current, or interrupting
current rating is placed in the circuit breaker
compartment. If an attempt to insert an
improperly rated circuit breaker into the circuit
breaker compartment is made, these plates
will interfere with each other and deter further
insertion. The interference will occur before
the circuit breaker reaches the disconnected
position. Do not attempt to force the circuit
breaker past the compartment interference
plate or remove the interference plates from
either the compartment or the circuit breaker.
Remove the incorrectly rated circuit breaker
and insert a properly rated circuit breaker into
the circuit breaker compartment.
30
1) Prior to Inserting the Circuit Breaker into the
Circuit Breaker Compartment
a. Check the Primary Disconnecting
Devices and Circuit Breaker
Compartment
Examine the primary disconnecting
devices for any signs of damage and
contamination. Check to see that none
are bent out of alignment.
If contamination is found refer to
Ch 5 Maintenance, B. Mechanism
Area, 2) Lubrication for cleaning and
lubrication procedures. If the primary
disconnecting devices are damaged
make no attempt to repair. Contact
Powell for further information.
Examine the circuit breaker
compartment to see that it is clean and
clear of debris that might interfere with
circuit breaker travel.
b. Racking the Circuit Breaker into the
Circuit Breaker Compartment
The described racking procedures
apply only for the PowlVac® ARM circuit
breaker. For all other constructions,
refer to the appropriate instructions or
instruction bulletin(s) for the applicable
racking procedures.
The circuit breaker is designed to be
electrically racked into the circuit
breaker compartment from a remote
location with the compartment door
closed. The ARM circuit breaker may
also be manually racked using the
emergency override option with the
compartment door open.
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Installation
01.4IB.65120
2) Inserting the Circuit Breaker to the
Test/Disconnected Position
CAUTION
Before inserting any circuit breaker into a
compartment, the user must verify that the
circuit breaker rating meets or exceeds the
metal-clad switchgear rating.
CAUTION
Before inserting a circuit breaker into the
circuit breaker compartment, be sure that
the indicator flag on the front cover
of the circuit breaker displays
“BREAKER TEST/DISCONNECTED”.
CAUTION
Before attempting to rack a circuit breaker
in or out of a circuit breaker compartment
equipped with a key interlock, make sure
that the interlock is unlocked and in the open
position.
CAUTION
Prior to inserting the circuit breaker into the
circuit breaker compartment, make sure that
the control circuits are deenergized.
a. Verify that the circuit breaker
open/closed indicator displays
“BREAKER OPEN”. If “CLOSED”, press
the manual trip operator to open the
circuit breaker.
b. To insert the circuit breaker into the
circuit breaker compartment, open
the compartment door and align the
wheels with the floor pan channels of
the compartment. Verify that the floor
pan channels are free of debris prior to
inserting the circuit breaker.
c. Roll the circuit breaker into the
compartment until the position
interlock bar and roller contacts a
positive stop.
Note: This is the Disconnected Position.
NOTICE
The illustrations shown for all racking
procedures are provided to show device
locations and are intended only as a guideline.
These illustrations may not be representative
of site specific safety practices for performing
the procedure. Before attempting any racking
procedure, review Chapter 2.
Installation
!
d. Insert the circuit breaker compartment’s
secondary disconnect plug
(Figure 13, c) into the circuit breaker
secondary disconnect receptacle
(Figure 13, b). Once the plug is
fully inserted, move the secondary
disconnect latch (Figure 13, a) from left
to right until it has engaged the housing
of the secondary disconnect plug
(Figure, 13, c).
e. Roll the circuit breaker into the
compartment until the racking crank
arms contact with the vertical slots in
the compartment.
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31
PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
The anti-rollout latch on the right side of
the circuit breaker will engage the tab in
the compartment, preventing accidental
removal of the circuit breaker from the
compartment.
Note: This is the Test Position.
Figure 13
Secondary Disconnecting Devices
3) Inserting the Circuit Breaker to the Connected
Position
NOTICE
The preferred method of racking the ARM
circuit breaker is electrically from a remote
location utilizing the ARM controller installed
in the switchgear. Refer to the ARM Controller
instruction bulletin provided with the
controller for detailed information on the
automatic racking procedures.
a
b
c
d
NOTICE
In the event of an emergency, such as loss of
ARM control power, the ARM circuit breaker
is equipped with an emergency racking
mechanism which enables racking the ARM
circuit breaker into or out of the connected
position.
e
The following emergency racking
procedure is intended to be used only in
the event of loss of control power, or failure
of the ARM controller or ARM circuit breaker
to operate electrically.
a.
b.
c.
d.
e.
Secondary Disconnect Latch
Secondary Disconnect Receptacle
Secondary Disconnect Plug
Secondary Disconnect Receptacle Guide
Interlock Bar
For instructions on inserting the circuit
breaker into the compartment refer to
Ch 4 Installation, E. Inserting the Circuit
Breaker into the Circuit Breaker Compartment,
2) Inserting the Circuit Breaker to the
Test/Disconnected Position.
!
CAUTION
Prior to inserting the circuit breaker into the
circuit breaker compartment, make sure that
the control circuits are deenergized.
32
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Installation
01.4IB.65120
a. Verify that the circuit breaker
open/closed indicator displays
“BREAKER OPEN” and if not, press the
manual trip operator to open the circuit
breaker.
b. To move the circuit breaker from the
Test/Disconnected position to the
Connected position in the circuit
breaker compartment, open the
emergency racking drive shaft shutter
(Figure 5, c) and place the racking
handle socket onto the emergency
racking drive shaft. The racking handle
socket may be used to push down the
shutter to gain access to the racking
drive shaft.
c. Turning the racking handle
counterclockwise will begin to rack the
circuit breaker into the compartment.
When the circuit breaker is racked into
the compartment, the force needed
to rotate the racking handle will be
high at the beginning of motion due
to the force required to start the rack
drive of the motor, as the movement
of the gears start the force will reduce.
Once the shutters are open, the circuit
breaker begins to move toward the
stationary primary disconnecting
devices. When the moveable primary
disconnecting devices of the circuit
breaker engage with the stationary
primary disconnecting devices of the
compartment, the force required to
rotate the racking handle will increase
appreciably. This force will decrease
as the primary disconnecting devices
spread and engage fully. Continuing
rotation of the racking handle will cause
the circuit breaker to travel further into
the compartment ensuring wipe or
overlap of the primary disconnecting
devices. Continue racking until the
breaker position indicator displays
Installation
“BREAKER CONNECTED”. When the
circuit breaker reaches the end of the
racking travel, the operator will notice
an increased amount of force. If the
operator continues to apply force, a
torque limiter on the racking handle
will produce a sharp clicking sound
indicating the torque limit is reached at
35-ft-lbs. Should the operator continue
to apply force, the torque limiter will
continue to operate with no further
buildup of torque on the circuit breaker
racking mechanism.
d. Once the circuit breaker has reached the
connected position, remove the racking
handle, verify that the emergency
racking drive shaft shutter has returned
to its normal position, close the
compartment door, and operate the
circuit breaker as required.
Note: This is the Connected Position.
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33
PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
F.Removing the Circuit Breaker From the Circuit
Breaker Compartment
!
CAUTION
Prior to removing the circuit breaker from the
circuit breaker compartment, make sure the
circuit breaker is in the open position and all
springs are discharged.
!
CAUTION
Prior to removing the circuit breaker from the
circuit breaker compartment, make sure that
the control circuits are deenergized.
1) Removing the Circuit Breaker from the
Connected to the Test/Disconnected Position
a. Verify that the circuit breaker
open/closed indicator displays
“BREAKER OPEN” . If “CLOSED”, close
door and open breaker from a remote
location or alternately by using the
circuit breaker control switch on
compartment door. Open door and
verify that the circuit breaker
open/closed indicator displays
“BREAKER OPEN”.
b. With the compartment door open, press
open the emergency racking drive shaft
shutter. Place the racking handle socket
onto the racking drive shaft shutter. The
racking handle socket may be used to
push down the shutter to gain access to
the racking drive.
c. Turn the racking handle clockwise until
the breaker position indicator displays
“BREAKER TEST/DISCONNECTED”.
d. Remove the racking handle and verify
that the emergency racking drive shaft
shutter has returned to its normal
position.
34
Note: This is the Test Position.
2) Removing the Circuit Breaker from the
Test/Disconnected Position out of the Circuit
Breaker Compartment
!
CAUTION
Prior to removing the circuit breaker from the
circuit breaker compartment, make sure that
the control circuits are deenergized.
!
CAUTION
Prior to removing the circuit breaker from the
circuit breaker compartment, make sure the
circuit breaker is in the open position and all
springs are discharged.
a. Open the circuit breaker compartment
door.
b. Remove the circuit breaker
compartment’s secondary disconnect
plug (Figure 13, c) by moving the
secondary disconnect latch
(Figure 13, a) from right to left. Store
the plug so that it will not be damaged
while withdrawing the circuit breaker.
!
CAUTION
Removal of the secondary disconnect plug
will trip a closed breaker and discharge the
main closing spring.
c. Press the anti-rollout latch
(Figure 1, r) to release the circuit breaker
and pull the circuit breaker out of the
circuit breaker compartment using the
handles.
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Installation
01.4IB.65120
Ch 5 Maintenance
A. General Description
!
CAUTION
Prior to beginning any maintenance
procedures, make certain that the control
circuits are deenergized and the circuit
breaker is resting securely outside the circuit
breaker compartment. Do not work on a
closed circuit breaker or a circuit breaker with
the main closing spring charged.
NOTICE
Before attempting any maintenance work,
it is important to study and fully understand
the safety practices outlined in Chapter 2 of
this instruction bulletin. If there is any reason
to believe there are any discrepancies in the
descriptions contained in this instruction
bulletin, or if they are deemed to be confusing
and/or not fully understood, contact Powell
immediately.
1)Introduction
Actual inspection and maintenance will
depend upon individual application
conditions such as number of operations,
magnitude of currents switched, desired
overall system reliability, and operating
environment. Any time the circuit breaker
is known to have interrupted a fault current
at or near its rating, it is recommended
that the circuit breaker be inspected and
the necessary maintenance be performed
as soon as practical. Some atmospheric
conditions such as extremes of dust,
moisture, or corrosive gases might indicate
inspection and maintenance at more
frequent intervals. Very clean and dry
conditions combined with low switching
duty will justify longer times between
inspection and maintenance operations.
With experience, each user can set an
inspection and maintenance schedule that
is best suited for use.
If maintenance is performed at longer
time intervals than one year, the vacuum
integrity test should be performed each
time the circuit breaker is removed from
the metal-clad switchgear for reasons other
than scheduled circuit breaker maintenance
if it has been more than one year since the
last vacuum integrity test.
A regular maintenance schedule must be
established to obtain the best service and
reliability from the circuit breaker.
PowlVac 38™ ARM circuit breakers
are designed to comply with industry
standards requiring maintenance every 500
operations depending upon the rating of
the circuit breaker, or once a year.
Maintenance
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35
PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
A permanent record of all maintenance
work should be kept, the degree of detail
depending upon the operating conditions.
The record will be a valuable reference for
subsequent maintenance work and for
station operation. It is also recommended
that the record include reports of tests
performed, the condition of circuit
breakers, and any repairs or adjustments
that were performed. This record should
begin with tests performed at the time of
installation and energization, and all data
should be graphed as a function of time to
ensure a proper maintenance cycle is being
scheduled.
Clean the circuit breaker by removing any
loose dust and dirt. Do not use compressed
air to clean dirt from the circuit breaker.
This may result in loose dirt or grit being
blown into bearings or other critical parts,
thus causing excessive wear. Use a vacuum
cleaner, or wipe with a dry lint-free cloth or
an industrial-type wiper to clean the circuit
breaker. Do not use solvents, de-greasers,
or any aerosol products to clean in the
area of any mechanisms. Refer to
Ch 5 Maintenance, B. Mechanism Area,
2) Lubrication for instructions on cleaning
the lubricated areas for the stored energy
mechanism and other specified parts.
Because of extensive quality control tests
made at the factory, the operations counter
on a new circuit breaker will normally
register over a hundred operations. The
reading of the operations counter should
be recorded when the circuit breaker
is placed into service and when any
maintenance work is performed.
Primary insulation, including the vacuum
interrupter supports and the operating
pushrods, should be cleaned. Wipe clean
with a dry, lint-free cloth or an industrial
type wiper. If dirt adheres and cannot be
removed by wiping, remove it with a mild
solvent such as denatured alcohol. Be
sure that the circuit breaker is dry before
returning it to service. Do not use any type
of detergent to wash the surface of the
insulators because detergent may leave
an electrically conducting residue on the
surface as it dries.
2) Inspection and Cleaning
CAUTION
When cleaning the circuit breaker insulating
supports and bus insulation, use only
denatured alcohol or isopropyl alcohol to
remove foreign material. Failure to do so may
damage the dielectric and/or the mechanism
properties of the insulation.
Visually check the circuit breaker for loose
or damaged parts. Tighten or replace
loose or missing hardware. Any damaged
parts that will interfere with the normal
operation of the circuit breaker should be
replaced. The inspection will be easier if the
front cover is removed.
36
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Maintenance
01.4IB.65120
B. Mechanism Area
1) Mechanical Operation
Remove the circuit breaker front cover
to expose the stored energy mechanism.
Make a careful visual inspection of the
mechanism for loose, damaged, or
excessively worn parts.
Note: If timing tests are performed as in,
Ch 5 Maintenance, D. Optional
Maintenance Procedures, do not
operate the circuit breaker until these
tests are completed. Operation of the
mechanism may alter the “As found”
operating condition of the circuit
breaker’s stored energy mechanism.
For further details, see
Ch 4 Installation, D. Placing the
Circuit Breaker Into Service,
4) Mechanical Operation Check.
A – Grease should be lightly applied to
those bearing surfaces that are accessible.
Inaccessible surfaces, such as bearings, may
be lubricated with a light synthetic machine
oil such as C - Oil. B – Grease should be
applied to the electrical contact surfaces.
Lubricate the stored energy mechanism
and other specified parts in accordance
with Table B, Lubrication. See Figures 14
and 15 for labeled lubrication photographs.
Table B, Lubrication lists the location of all
surfaces that should be lubricated, the type
of lubricant to be used, and the method of
applying the lubricant. The guiding rule
in lubrication is to lubricate regularly, use
lubricant sparingly and remove all excess
lubricant. Tilting the circuit breaker will
enable the lubricant to cover the bearing
surfaces.
2) Lubrication
CAUTION
Before applying any type of lubrication to the
circuit breaker, the stored energy mechanism
should be in the open position, and all springs
should be discharged.
Powell offers a complete lubrication kit
(Powlube-104) which contains all the
lubricants required for maintaining the
circuit breakers. Powlube-104 consists
of (1) A-grease, (1) B-grease, and (1) C-oil.
Prior to March 2014, Powell provided
Powlube-101 and Powlube-102 which
contained (1) tube of Anderol 757 or
Rheolube 368A, (1) tube of Mobilgrease 28
and (1) bottle of Anderol A456 oil.
Maintenance
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37
PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
Table B Lubrication
Reference
Figure
Lubricant
Figure 14, b
B - Grease
Wipe clean. Apply lubricant only to actual contact surface.
Secondary Disconnect Receptacle
Figure 14, g
B - Grease
Wipe clean. Apply lubricant only to actual contact surface.
Ground Connection
Figure 15, ac
B - Grease
Wipe clean. Apply lubricant only to actual contact surface.
Spring Yoke Pin
Figure 14, a
A - Grease
Primary Trip Prop Bearing
Figure 14, c
C - Oil
Remove main closing spring.
Primary Trip Prop Roller
Figure 15, q
C - Oil
Remove main closing spring.
Trip Shaft Bearing
Figure 14, d
C - Oil
Jackshaft Support
Figure 14, f
A - Grease
Pawl Support Arm
Figure 14, i
C - Oil
Crank Pin
Figure 14, h
A - Grease
Motor Drive Shaft Roller Needle
Bearings
Figure 14, m
C - Oil
Location
Method
Electrical Parts
Primary Disconnecting Device
Mechanical Parts
Pawls
Figure 14, j
C - Oil
Close Latch Shaft Face
Figure 14, n
A - Grease
Ratchet Wheel
Figure 14, k
A - Grease
Fundamental Linkage Pin
Figure 14, e
C - Oil
Racking Mechanism
Figure 15, p
C - Oil
A - Grease
Main Closing Spring Guide Rod
Figure 15, o
A - Grease
Secondary Linkage Roller
Figure 15, r
C - Oil
Primary Trip Prop
Figure 15, s
C - Oil
Open-Close Flag Drive Lever Pin at
Jackshaft
Figure 15, t
C - Oil
Flag Support Pin
Figure 15, v
C - Oil
Jackshaft Outer Bearings Support
Figure 15, w
C - Oil
Motor Drive Shaft Coupling
Figure 15, y
A - Grease
Wheel
Figure 14, l
A - Grease
Motor Drive Shaft Support
Bearings
Figure 15, aa
C - Oil
Camshaft Needle Bearings
Figure 15, z
C - Oil
Close Shaft Support Bearings
Figure 15, x
C - Oil
Motor Cutoff Cam
Figure 15, ab
A - Grease
Fundamental Linkage
Figure 15, u
C - Oil
Apply a light coating of grease and remove all excess.
Apply to penetrate where pin passes through end link.
Apply C - Oil to the crank arm rollers and racking crank arms.
Wipe clean. Apply A - Grease to worm gear.
Remove main closing spring.
Apply to peripheral surface only.
Apply to penetrate where pins pass through links.
Note: For all previous lubrication requirements Powlube-104 A-Grease replaces Anderol 757 and
Rheolube 368A, B-Grease replaces Mobilgrease 28 and C-Oil replaces Mobil 1 and Anderol 456.
See Ch 5 Maintenance, B. Mechanism Area, 2) Lubrication for more details.
38
Powered by Safety®
Maintenance
01.4IB.65120
Figure 14
Lubrication
a
b
c
d
f
h
a. Spring Yoke
Pin
b.Primary
Disconnecting
Device
c. Primary Trip
Prop Bearing
d. Trip Shaft
Bearing
e
g
i
j
k
l
m n
e.Fundamental
Linkage Pin
f.Jackshaft
Support
g.Secondary
Disconnect
Receptacle
h. Crank Pin
i.
j.Pawls
k. Ratchet Wheel
l.Wheel
m. Motor Drive
Shaft Roller
Needle
Bearings
n. Close Latch
Shaft Face
Maintenance
Powered by Safety®
Pawl Support
Arm
39
PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
Figure 15
Lubrication (cont)
o
p
q
s
t
v
aa ab
Primary Trip
Prop
y. Motor Drive
Shaft Coupling
40
p.Racking
Mechanism
q. Primary Trip
Prop Roller
r.Secondary
Linkage Roller
r
u
w
x
z
y
s.
o. Main Closing
Spring Guide
Rod
t.Open-Closed
Flag Drive
Lever Pin at
Jackshaft
z.Camshaft
Needle
Bearings
ac
u.Fundamental
Linkage
v. Flag Support
Pin
aa. Motor Drive
Shaft Support
Bearings
Powered by Safety®
w.Jackshaft
x. Close Shaft
Outer Bearings
Support
Support
Bearing
ab. Motor Cutoff
Cam
ac.Ground
Connection
Maintenance
01.4IB.65120
3) Closing Spring Removal
2. Remove the horizontal bracket at
the top of the main closing spring by
unfastening the two attachment bolts.
3. Remove the spacer from below the
bracket.
4. Turn the bracket 90˚, and replace it on
the top of the spring yoke.
5. Place the spacer above the bracket with
the flat washer above the spacer.
6. Insert bolt and tighten until the tension
is taken off the connecting rods.
7. With a slight rocking motion of the
main closing spring assembly, the
connecting rods (Figure 16, e) can now
be unhooked from the spring yoke pins
and the main closing spring assembly
can be removed.
The closing spring must be removed
in order to perform slow closing of
mechanism.
Although main closing spring removal is
usually not necessary for lubrication, it may
be necessary for performing adjustments
or major overhaul tasks. Furthermore,
removal of the main closing spring permits
slow closing of the mechanism and the
vacuum interrupter contacts. For details,
see Ch 5 Maintenance, B. Mechanism Area,
4) Slow Closing of Mechanism.
Figure 16
Main Closing Spring Assembly
Compressed for Removal
Note: Care should be taken on reassembly
to ensure correct location of the
flat washer, lock washer and spacer
(Figure 17).
a
b
c
d
Figure 17
e
Main Closing Spring Assembly
Installed
a
b
a.Bolt
b.Bracket
c. Flat Washer
d.Spacer
e. Connecting Rod
c
e
d
The procedure for spring removal is as
follows:
1. With the main closing spring discharged
and the circuit breaker contacts open,
remove the bolt at the top of the spring
rod together with the flat washer and
lock washer.
Maintenance
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a.Bolt
b.Bracket
c. Lock Washer
d. Flat Washer
e.Spacer
41
PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
4) Slow Closing of Mechanism
5) Mechanism Adjustments
The slow closing of mechanism described
is not required for routine maintenance;
however, it may be a useful procedure
for troubleshooting circuit breaker
misoperation.
1. With the main closing spring assembly
removed, rotate the camshaft so that
the crank arms are pointing downward.
The fundamental linkage will now move
into the reset position.
2. Push the manual close operator inward
and hold it in while operating the
charging handle to rotate the camshaft.
3. When the close release latch arm has
passed the close shaft latch plate, the
manual close operator may be released.
As the main closing cam engages
the main cam roller, the jackshaft will
commence to rotate.
4. Continue to operate the charging
handle until the crank arms point
downward. The circuit breaker will
now be closed and there will be a gap
between the operating pushrod lock
nuts and the pivot blocks.
5. Return the circuit breaker to the open
position by depressing the manual trip
operator.
6. To install the main closing spring
assembly reverse the preceding removal
procedure.
!
WARNING
When any maintenance procedure requires
the opening or closing of the circuit breaker
or the charging of any of the stored energy
mechanism springs, exercise extreme caution
to make sure that all personnel, tools, and
other miscellaneous objects are kept well clear
of the moving parts or the charged springs.
Failure to do this may cause serious damage
or injury to the circuit breaker or personnel.
Several factory adjustments in the stored
energy mechanism are described in this
section. NO ADJUSTMENT OF THESE
SETTINGS IS REQUIRED FOR ROUTINE
MAINTENANCE, but they may need to be
adjusted after a major overhaul or removal
of the mechanism.
!
CAUTION
Do not adjust these setting unnecessarily as
damage to the circuit breaker may result.
a. Adjustment of Ratchet Wheel Holding
Pawl
The holding pawl support arm
(Figure 6, d) is adjusted by the holding
pawl adjusting eccentric (Figure 6, f ).
If the pawl is not properly adjusted,
there will be a “knocking” noise when
the ratchet mechanism is operating or
the stored energy mechanism will not
ratchet at all.
42
Powered by Safety®
Maintenance
01.4IB.65120
b. Adjustment of Primary & Secondary
Trip Prop
To adjust the pawl perform the
following steps:
1. Remove the escutcheon to gain
access to the head of the bolt
holding the adjusting eccentric.
2. Loosen the bolt slightly.
3. Grip the eccentric with a pair of
slip-joint pliers or a similar tool and
rotate the stop slightly.
4. Tighten the holding bolt with the
eccentric in the new position.
5. While charging the main closing
springs, using the charging motor
to drive the mechanism, observe
the ratcheting operation for
improvement.
6. If the ratcheting operation has not
improved, repeat the preceding
sequence until the ratcheting
operation is smooth. This may
require several charging cycles.
7. When the eccentric is properly set
replace the escutcheon.
Be sure that the escutcheon is
reinstalled on the proper circuit breaker,
since the escutcheon contains the
nameplate with the circuit breaker’s
rating and serial number information.
The serial number of the circuit breaker
is also attached to the circuit breaker
frame near the ground connection on
an engraved metal plate. The serial
number found on the nameplate must
match the number affixed to the frame.
Maintenance
Figure 18
Primary & Secondary Trip Prop
Adjustment
a
b
c
0.005-0.015"
d
f
e
a. Secondary Trip Prop
b. Primary Trip Prop Roller
c. Primary Trip Prop
d. Primary Trip Prop Adjusting Screw
e.Rivet
f. Trip Bar
Perform the following procedures to
adjust the primary trip prop:
1. Remove the main closing spring.
Refer to Ch 5 Maintenance,
B. Mechanism Area, 3) Closing Spring
Removal.
2. Adjust the primary trip prop
adjusting screw (Figure 18, d) so
that with the fundamental linkage
in the reset position, the clearance
between the primary trip prop
roller and the secondary trip prop
is 0.005” to 0.015”. The primary trip
prop adjusting screw is accessible
from the rear of the stored energy
mechanism and is located inside
the hole beside the lower middle
insulator supporting the live part
assembly.
3. Replace the main closing spring.
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43
PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
c. Tripping System Adjustment
!
adjusting screw at the moment the
breaker operates. Do NOT turn the
screw any further clockwise after the
breaker operates.
7. Turn the secondary trip prop
adjusting screw (Figure 6, b)
counter-clockwise 1½ full turns from
the position noted in step 6.
8. While holding the secondary trip
prop adjusting screw from turning,
securely tighten the secondary trip
prop adjusting screw locking nut.
9. Manually charge the main closing
spring using the manual charge
handle per Ch 4 Installation,
D. Placing the Circuit Breaker Into
Service, 4) Mechanical Operation
Check.
10.Manually CLOSE the circuit breaker.
11.Using leaf type feeler gauges with
a total of 0.090” thickness selected,
position the feeler gauge as shown
in Figure 19.
WARNING
Prior to performing any adjustment or
maintenance procedure, all high voltage
components shall be deenergized,
disconnected by means of a visible break, and
securely grounded.
To adjust the PowlVac 38™ ARM Tripping
System perform the following steps:
1. Prior to performing this adjustment
procedure, all high voltage
components shall be deenergized,
disconnected by means of visible
break and securely grounded, and
ensure that the control circuits are
deenergized.
2. Remove the circuit breaker front
cover.
3. Loosen the secondary trip prop
adjusting screw locking nut several
full turns.
!
Figure 19
CAUTION
Do NOT allow the secondary trip prop
adjusting screw to turn while loosening the
locking nut. Failure to observe this caution
will severely damage the mechanism.
a
b
4. Manually charge the circuit breaker
main spring.
5. Manually CLOSE the circuit breaker.
6. Slowly turn the secondary trip prop
adjusting screw (Figure 6, b)
clockwise in 1/8 turn (45˚)
increments until the breaker trips
OPEN. Carefully note the rotational
position of the tool used to turn the
44
Feeler Gauge
Powered by Safety®
a. Trip Coil Armature
b. Feeler Gauge
Maintenance
01.4IB.65120
12.Slowly depress the trip coil
armature (Figure 19, a) using
the manual charge handle or
screwdriver and position the tool
as shown in Figure 19. Depress the
handle until the armature contacts
the feeler gauges. The circuit
breaker should not trip.
Note: Do NOT tilt the armature. Tilting the
armature by applying a load to the
right of the feeler gauges will produce
incorrect results.
13.Choose one of the following steps
according to the TRIP status:
i. If the circuit breaker TRIPPED
during the test performed in
step 12, increase the gap
between the trip coil armature
and the latch check operator
by bending the latch check
operator downwards slightly
using channel lock pliers or a
small crescent wrench. Repeat
steps 9 through 12.
Note: Bend the latch check operator in very
small increments. This process may
take several attempts.
ii. If the circuit breaker did NOT
TRIP during the test performed
in step 12, proceed to step 14.
14.Reset the feeler gauges with 0.030”
selected and position the feeler
gauge as shown in Figure 19.
15.Slowly depress the trip coil armature
using the manual charge handle.
Position the handle as shown in
Figure 19. Depress the handle until
the armature contacts the feeler
gauges. The circuit breaker should
trip.
Maintenance
Note: Do NOT tilt the armature. Tilting the
armature by applying a load to the
right of the feeler gauges will produce
incorrect results.
16.If the circuit breaker did not TRIP
during the test performed in
step 15, remove the feeler gauges
and trip the breaker. Decrease the
gap between the trip coil armature
and the latch check operator by
bending the latch check operator
upwards slightly using channel lock
pliers or a small crescent wrench.
Note: Bend the latch check operator in very
small increments. This process may
take several attempts.
17.Repeat steps 9 through 16 until
the breaker does not trip with the
0.090” gauge inserted in the trip coil
armature gap and does trip with the
0.030” gauge inserted into the trip
coil armature gap.
18.Manually charge the main closing
spring using the manual charge
handle per Ch 4 Installation,
D. Placing the Circuit Breaker Into
Service, 4) Mechanical Operation
Check.
19.Replace circuit breaker front cover.
d. Latch Check Switch Adjustment
The latch check switch adjustment
(Figure 20) described is not required
for routine maintenance; however,
the latch check switch may need to be
adjusted after major overhaul, removal
of the mechanism, or tripping system
adjustment.
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45
PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
Figure 20
Latch Check Switch Adjustment
a
b
Pivot Screw
a.
b.
c.
d.
0.045"
d
c
Latch Check Switch
Latch Check Operator
Secondary Trip Prop Adjusting Screw
Secondary Trip Prop Adjusting Screw Nut
To adjust the latch check switch perform
the following steps:
1. Remove the main closing spring.
Refer to Ch 5 Maintenance,
B. Mechanism Area, 3) Closing Spring
Removal.
2. Rotate the crank arms until the
spring charge indicator displays,
CLOSING SPRING CHARGED.
3. Loosen the two screws which secure
the latch check switch and rotate
the latch check switch about the
pivot screw downward to the lowest
position allowed. The latch switch
contacts are now OPEN.
4. Insert a 0.045” gauge between
the secondary trip prop adjusting
screw (Figure 20, c) and latch check
operator. Rotate the latch check
switch upwards until the contacts
are closed. (An audible click of
the contacts will be heard). At the
position where the click is heard
hold the switch and retighten the
two screws which secure the latch
check switch. Remove the gauge.
46
5. To confirm that the latch check
switch is properly set, slowly depress
and release the manual trip operator
to verify that the latch check switch
OPENS and CLOSES properly. (An
audible click of the contacts will
be heard). The latch check switch
contacts will OPEN as the latch
check operator is moved by the
manual trip operator away from
the secondary trip prop adjusting
screw. Slowly withdraw the manual
trip operator and the latch check
switch contacts should close when
the latch check operator is between
0.045” to 0.015” away from the
secondary trip prop adjusting screw.
6. Depress the manual close operator
and rotate the crank arm until
resistance is felt.
7. Depress and hold the manual trip
operator inward and rotate the
crank arms until the spring charge
indicator displays, CLOSING SPRING
DISCHARGED.
8. Reinstall the circuit breaker main
closing spring.
e. Adjustment of Close Latch Shaft
The close latch shaft (Figure 6, l) passes
through the side sheets of the stored
energy mechanism frame at the front of
and below the cam shaft. One end of
the shaft is shaped to make a latch face
and interferes with the close latch arm
(Figure 6, k), which is fixed to the cam
shaft. The other end of the close latch
shaft is attached to a lever positioned
by a close bar adjusting screw
(Figure 6, r).
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Maintenance
01.4IB.65120
To adjust the close latch shaft perform
the following procedures:
1. Remove the escutcheon.
2. Loosen the locking nut from the
close bar adjusting screw while
holding the position of the close bar
adjusting screw with a screw driver.
3. Back out the close bar adjusting
screw by turning the screw
counterclockwise 2 full turns.
4. Manually charge the circuit breaker
main closing spring with a manual
charging handle until the spring
charge indicator displays CLOSING
SPRING CHARGED.
5. Turn the close bar adjusting screw
clockwise until the main closing
spring discharges, then depress the
manual trip operator to OPEN the
circuit breaker.
6. Turn the close bar adjusting screw
3 to 3½ full turns counterclockwise.
Retighten the locking nut holding
the screw.
7.Repeat step 4. Then CLOSE and
OPEN the circuit breaker to ensure
proper operation.
8. Replace the escutcheon.
6) Electrical Operation
After performing any necessary mechanical
and lubrication maintenance, operate the
circuit breaker electrically several times to
ensure that the electrical control system
works properly. See Ch 4 Installation,
D. Placing the Circuit Breaker Into Service,
5) Electrical Operation Check.
Maintenance
C. Vacuum Interrupter and Contact Area
1) Vacuum Interrupter and Contact Erosion
At each inspection the vacuum interrupters
should be checked for contact erosion.
The circuit breaker must be closed for this
check. Each new vacuum interrupter is
set with a gap of about 0.150” to 0.188”
between the high voltage pivot block and
the flat washer on the operating pushrod
stud. As the contacts erode with use, this
gap will decrease. The factory setting of
the lock nut gap varies for each vacuum
interrupter.
The contact travel of the vacuum
interrupter contacts is measured by
subtracting the lengths between the top
of the front terminal clamp in both open
and closed positions and the vacuum
interrupter. Refer to Ch 6 Recommended
Renewal Parts and Repair Procedures,
C. Replacement Procedures, 1) Vacuum
Interrupter Assembly.
2) Vacuum Integrity
Refer to Ch 4 Installation, D. Placing the
Circuit Breaker Into Service,
2) Vacuum Integrity for information on
vacuum integrity and testing of vacuum
interrupters.
3) Mechanical Adjustment of Vacuum Interrupters
There are no adjustments required
for routine maintenance of a vacuum
interrupter assembly. There are several
factory adjustments which will vary over
the operating life of the vacuum interrupter.
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47
PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
!
2) Timing
CAUTION
Adjustments of these settings is only
necessary when repair requires the removal
or replacement of the vacuum interrupter.
Do not adjust these settings unnecessarily as
damage to the circuit breaker may result.
When it is necessary to remove or replace
the vacuum interrupter, refer to
Ch 6 Recommended Renewal Parts and
Replacement Procedures, C. Replacement
Procedures, 1) Vacuum Interrupter Assembly
or contact the Powell Service Division.
D.Optional Maintenance Procedures
1) High Potential Tests
High potential tests are not required for
routine maintenance but are recommended
after a heavy fault interruption, any major
circuit breaker repair that involves the
primary current path or when the circuit
breaker has been in storage for an extended
time, especially in a damp location or
other adverse environment. In these cases,
both the High Voltage Insulation Integrity
and Control Voltage Insulation Integrity
tests should be performed. For details of
maintenance procedures, see
Ch 4 Installation, D. Placing the Circuit
Breaker Into Service.
48
Perform CLOSE and OPEN timing tests at
the nominal control voltage. The voltage is
printed on the circuit breaker nameplate.
To measure CLOSE timing, operate the test
source to the CLOSE position. When the
circuit breaker closes, record the closing
time. The closing time from energizing the
closing coil to vacuum interrupter contact
touch should not exceed the values in
Table C, Timing.
Table C Timing
Cycles
Closing Time
(ms)
Tripping Time
(ms)
3
< 80
< 35
5
< 80
< 55
To measure OPEN timing, operate the test
source to the OPEN position. When the
circuit breaker opens, record the tripping
time. Operate the test source to the OPEN
position to open the circuit breaker and
record the opening time. The opening
time from energizing the shunt trip coil to
vacuum interrupter contact part should not
exceed the values listed in Table C, Timing.
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Maintenance
01.4IB.65120
3) Primary Resistance Check
This check is not required for routine
maintenance but it is recommended after
any major maintenance that requires
disassembly of any part of the primary
current path.
To check the primary resistance, pass a
minimum of 100A DC through the circuit
breaker pole, with the circuit breaker
closed. Measure the voltage drop across
the primary contacts and calculate
the resistance. The resistance should
not exceed the values provided in this
instruction bulletin for the specific type
and rating of the circuit breaker being
measured.
The micro-ohm values of resistance must
not exceed the limits in Table D, Primary
Resistance.
Table D Primary Resistance
Continuous
Resistance
Current
(Micro-ohms)
(Amperes)
Breaker
Type
Rated
(kV)
38PV40ARM
38
1200
46
38PV40ARM
38
2000
36
Maintenance
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49
PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
Ch 6 Recommended Renewal Parts and
Replacement Procedures
A.Ordering Instructions
1. Order Renewal Parts from Powell at
powellind.com or call 1.800.480.7273.
2. Always specify the complete nameplate
information including:
•
•
•
•
•
•
Breaker Type
Serial Number
Rated Voltage
Rated Amps
Impulse Withstand
Control Voltage (for control devices and
coils)
3. Specify the quantity and description
of the part and the instruction bulletin
number. If the part is in any of the
recommended renewal parts tables, specify
the catalog number. If the part is not in
any of the tables, a description should be
accompanied by a marked illustration from
this instruction bulletin, a photo or simply
submit a sketch showing the part needed.
Since parts may be improved periodically,
renewal parts may not be identical to the
original parts. Tables E, F, and G list the
recommended spare parts to be carried in
stock by the user. The recommended quantity
is not specified. This must be determined
by the user based on the application. As a
minimum, it is recommended that one set of
parts be stocked per ten circuit breakers or less.
Powell recommends that only qualified
technicians perform maintenance on these
units. Refer to the Qualified Person Section in
the front of this instruction bulletin. If these
circuit breakers are installed in a location
where they are not maintained by a qualified
technician, a spare circuit breaker should be on
site ready for circuit breaker replacement. The
malfunctioning unit can then be returned to
the factory for reconditioning.
C.Replacement Procedures
This section includes instructions for replacing
the parts recommended as renewal parts.
Before attempting any maintenance repair
work, take note of the safety practices outlined
in Ch 2 Safety of this instruction bulletin.
B.Recommended Renewal Parts
!
A sufficient amount of renewal parts should
be stored to enable the prompt replacement
of any worn, broken, or damaged part. A
sufficient amount of stocked parts minimizes
service interruptions caused by breakdowns
and saves time and expense. When continuous
operation is a primary consideration a larger
quantity of renewal parts should be stocked
depending on the severity of the service and
the time required to secure replacement parts.
50
CAUTION
Ensure that the control circuits are
deenergized and the circuit breaker is
deenergized, disconnected by means of a
visible break, and securely grounded. Do NOT
start to work on a closed circuit breaker or a
circuit breaker with the main closing spring
charged. When any maintenance procedure
requires the opening or closing of the circuit
breaker or the charging of any of the stored
energy mechanism springs, exercise extreme
caution to ensure that all personnel, tools, and
other miscellaneous objects are kept clear of
the moving parts of the charged springs.
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Recommended Renewal Parts and Replacement Procedures
01.4IB.65120
1) Vacuum Interrupter Assembly
CAUTION
The vacuum interrupter should only be
replaced by a qualified person or a Powell
Service technician. Contact Powell for further
assistance at 1.800.480.7273.
This assembly (Figure 23, b) is located
between the upper and lower primary
disconnecting devices (Figure 2, a & e).
Refer to Figures 21 & 22, Vacuum
Interrupter Assembly Drawing, while
performing the following instructions. The
numbers in parenthesis after the part name
coordinate with the part numbers on the
vacuum interrupter assembly drawing.
a.Disassembly
i. Ensure all operating springs are
discharged and the circuit breaker is
open.
ii. With the circuit breaker in the OPEN
and DISCHARGED position, loosen
both of the socket set screws (32)
from the primary conductor.
iii. Using a strap wrench, remove the
primary conductor (31). Take care
not to damage the copper primary.
iv. Remove the electrostatic shield (12).
v. Remove the hex head bolts (21)
releasing the top of the vacuum
interrupter (2).
vi. With a pencil, trace an outline of
the bottom bus support (10) on the
high voltage housing (1). During
reassembly, the outline will enable
proper alignment of these devices.
vii. Remove both hex head cap screws
(28), flat washers, and lock washers.
Recommended Renewal Parts and Replacement Procedures
viii.Carefully loosen and remove 3 of 4
button head cap screws (13). Notice
that shims (approximately ⁵/₈” OD,
and ³/₈” ID) may be located behind
the bottom bus support (10). If
shims are used, they are held in
place by the button head cap
screw (13).
Note: It is important to document the
location and size of the shims to
enable proper reassembly of the
bottom bus support (10).
ix. Remove the last of the 4 button
head cap screws (13) described in
step viii and remove the combined
bottom bus support (10) and the
lower bus connector (11). It is
important to hold the vacuum
interrupter (2) securely to avoid
allowing the pushrod to tilt enough
to strike the circuit breaker frame.
The pushrod will break if it hits the
frame with sufficient force.
x. While holding the front terminal
clamp (3) to prevent it from tilting,
loosen the socket head bolt (17).
Unscrew the vacuum interrupter
(2) and the assembly from the
operating pushrod (3). Use care
to avoid allowing the operating
pushrod (3) to hit the circuit breaker
frame.
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51
PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
xi. Place the vacuum interrupter (2)
and the front terminal clamp (3)
on a level surface such as a table,
to remove the socket head bolt
(17). Before unscrewing the front
terminal clamp (3), observe and
document the distance that the
front terminal clamp (3) is screwed
onto the threads of the vacuum
interrupter (2). It is important to
document the location of these
devices to enable proper future
reassembly.
Note: It is important to observe and
document the location and
orientation of the shunt (19) to enable
future proper reassembly. Notice that
the shunt points in the same direction
as the label on the vacuum interrupter
(2), as well as the two bolt holes on
top of the vacuum interrupter (2).
xii. Unscrew the front terminal clamp
(3) and the shunt (19). It may be
necessary to wedge a screw driver
blade into the slot of the front
terminal clamp (3) only enough to
easily remove the clamp.
b.Assembly
Note: Refer to documentation required
in Ch 6 Recommended Renewal
Parts and Replacement
Procedures, C. Replacement
Procedures, 1) Vacuum Interrupter
Assembly, a. Disassembly, steps
vii through ix.
i. Prior to assembly, clean all parts,
including the high voltage housing
(1) with denatured alcohol.
52
ii. Screw the front terminal clamp (3)
and the shunt (19) back on the new
vacuum interrupter (2).
Approximately 1 to 3 threads of the
vacuum interrupter (2) should be
visible beneath the lowest surface
of the front terminal clamp (3). The
label of the vacuum interrupter
(2) should be pointed in the same
direction as the shunt (19), as well
as in the same direction as the two
holes in the top of the vacuum
interrupter (2).
Note: The vacuum interrupter label should
be visible from the back side of the
circuit breaker.
iii. Hold the front terminal clamp (3) in
place to prevent it from tilting and
torque the socket head bolt (17) to
30 ft.-lbs.
iv. Screw the vacuum interrupter
(2) and the assembly onto the
operating pushrod (4) until it stops.
v. Tilt the vacuum interrupter (2) and
the assembly back up to its original
position and look down through
the two holes of the upper primary
assembly (32) to assure that they
align with the bolt holes in the
vacuum interrupter (2). If the device
bolt holes do not align, follow these
steps:
aa. Hold the high voltage regulator
disc (7) with channel lock pliers
and loosen the two hex head
nuts (27) only enough (no more
than 3 turns) to enable rotation
of the whole assembly by hand
with no resistance.
ab.Align the hex head cap screws
(26) to the threads of the
vacuum interrupter (2).
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01.4IB.65120
ac. Insert a 1½” temporary bolt of
the same thread size as that was
removed through the upper
primary assembly (32) and into
the vacuum interrupter (2).
ad.Tighten the temporary bolt
enough to pull the vacuum
interrupter (2) back up, which
will start opening the contacts
inside.
ae. Replace the temporary bolt with
the original hardware when the
vacuum interrupter (2) is pulled
far enough to align the bolt
holes.
af. Torque the original bolts to
50 ft.-lbs.
vi. Grasp the bell portion of the
operating pushrod (4) and tighten
it by hand onto the vacuum
interrupter (2). Hold the high
voltage regulator disc (7) with
channel lock pliers and tighten the
hex head nuts (27).
vii. Install the button head cap
screws (28).
viii.Install the bottom bus support
(10) onto the high voltage housing
(1) and align the bus support
and housing to the pencil marks.
If shims were found during
Disassembly step viii, replace the
shims in the original positions.
Apply Lock-Tite 243 to the button
head cap screws and install them.
ix. Apply Lock-Tite 243 to the hex head
screws and install and torque the
screws to 30 ft.-lbs.
x. Torque the hex nuts (25) and the hex
head cap screw (21) to 30 ft.-lbs.
xi. Install the electrostatic shield (12),
then the primary disconnecting
device (31) onto the lower bus
connector (11).
Recommended Renewal Parts and Replacement Procedures
xii. Torque the primary disconnecting
device to 70 ft.-lbs. and reinstall hex
head cap screws (29).
xiii.Tighten the socket set screws (28).
Note: Make certain the hardware is torqued
correctly and the parts are installed
in the same positions as they were
before being removed.
!
WARNING
When any maintenance procedure requires
the opening or closing of the circuit breaker
or the charging of any of the stored energy
mechanism springs, exercise extreme caution
to make sure that all personnel, tools, and
other miscellaneous objects are kept well clear
of the moving parts or the charged springs.
Failure to do this may cause serious damage
or injury to the circuit breaker or personnel.
c.Verification
i. Charge and close the circuit breaker.
There should be a gap between the
flat washer (16) and the high voltage
pivot (9) of Figure 21 Vacuum
Interrupter Assembly Drawing
1200A, Detail A or Figure 22 Vacuum
Interrupter Assembly Drawing
2000A, Detail A.
ii. The gap between the flat washer
(16) and the high voltage pivot (9)
should be set between 0.150” and
0.188” on a new vacuum interrupter
with no operations. As the devices
are operated, the gap may decrease
over time due to erosion of the
primary contacts.
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53
PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
iii. If the gap needs to be increased,
hold the high voltage regulator
disc (7) with channel lock pliers,
loosen the hex head nut (27) and
turn the high voltage regulator disc
(7) counterclockwise. Retighten
the hex head nut (27) and measure
the gap again. Do not allow the
pushrod (4) to turn.
Note: Make sure the circuit breaker is in
the open position and all springs are
discharged.
iv. If the gap needs to be decreased,
hold the high voltage regulator disc
(7) with channel lock pliers, loosen
the hex head nut (27) and turn the
high voltage regulator disc (7) to the
right. Retighten the hex head nut
(27) and measure the gap again.
2) Closing Coil Assembly
Refer to service manual 01.4SM.1300
Closing Coil Assembly for replacement and
installation procedures.
3) Primary Shunt Trip Coil Assembly
6) Charging Motor Assembly
Refer to service manual 01.4SM.1200
Charging Motor Assembly for replacement
and installation procedures.
7) Anti-Pump Relay Assembly
Refer to service manual 01.4SM.1000
Anti-Pump Relay Assembly for replacement
and installation procedures.
8) Latch Check Switch
Refer to service manual 01.4SM.1400 Latch
Check Switch Assembly & Tripping System
Mechanism Adjustment for replacement and
installation procedures.
9) Motor Cutoff Switch Assembly
Refer to service manual 01.4SM.1500 Motor
Cutoff Switch Assembly for replacement and
installation procedures.
10)Auxiliary Switch
Refer to service manual 01.4SM.1100
Auxiliary Switch Assembly for replacement
and installation procedures.
Refer to service manual 01.4SM.1600
Primary Shunt Trip Coil Assembly for
replacement and installation procedures.
4) Secondary Shunt Trip Coil Assembly
Refer to service manual 01.4SM.1700
Secondary Shunt Trip Coil Assembly for
replacement and installation procedures.
5) Undervoltage Device Assembly (UV)
Refer to service manual 01.4SM.1800B
Undervoltage Assembly for replacement and
installation procedures.
54
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01.4IB.65120
Figure 21
Vacuum Interrupter Assembly
Drawing (38kV, 1200A)
Detail A - Breaker in Closed Position
0.150” - 0.188”
9
16
7
Recommended Renewal Parts and Replacement Procedures
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55
PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
Table E Vacuum Interrupter Assembly Parts List - 1200A
Part Number
Qty
Item
40703G01
1
1
High Voltage Module Assembly
WL35616BP
1
2
VI 38kV 40kA
40773P01
1
3
Front Terminal Clamp
43645P01
1
4
Pushrod, PVAC 38
43646P01
1
5
Regulator, Bias Spring
40093P01
1
6
High Voltage Disc 250MVA
40117P01
1
7
High Voltage Regulator Disc
43641P01
1
8
High Voltage Spacer
43625P01
1
9
High Voltage Pivot
40705P01
1
10
Bottom Bus Support
42078P01
1
11
Lower Bus Connector
42904P01
1
12
Shield, Electrostatic
73755
8
13
1/4 - 20 x 3/4” Button Head Socket Cap Screw S/S
W5005
11
14
5/16” Split Lock Washer
W5205
12
15
5/16” Flat Washer Type A Wide Gold Irridite Finish
W0019
3
16
½" Flat washer, Type AN thick
W0273
1
17
5/16” - 18 x 2” Socket Head Cap Screw
40002P01
1
18
Bias Spring 750MVA Dark Green
40723P01
1
19
Shunt, 1200A
W5206
4
20
3/8” Split Lock washer
W1028
2
21
1/2” - 13 x 4” Hex Head Cap Screw
W5006
2
22
3/8” Split Lock Washer
W1053
2
23
5/16-18 x 2 Hex Head Bolt
W3006
2
24
5/16” - 18 Hex Nut
W3007
2
25
Hex Nut 3/8” - 16
HexCapScrewInch
2
26
HexCapScrewInch
W3007
2
27
HexNut 3/8” - 16
73783
3
28
5/16” - 18 x 1 ¾" Button Head Socket Cap Screw S/S
W5005
3
29
5/16” Split Lock Washer
W5211
3
30
¼ Flat Washer Type A wide brass
43606G02
1
31
Lower Primary Disc Assy PV38, 1200AMP GE Cluster Style (Consisits of: (1) 43606P60,
(1) 43606G01, (1) 43606P65, (1) 43606P62, (1) W0206, (1) 0.3125, and (2) W1080)
43606G04
1
32
Upper Primary Disc. Assy. PV38, 1200AMP GE Cluster Style (Consists of: (1) 43606P60,
(1) 43606G01, (1) 43606P62, (1) 43606P65, (1) 43606P62, (1) W0206, (1) 0.3125, (2) W1080,
(1) 43606P63, (3) W5006, (3) 73816, (1) 40707P01, and (1) 40706P01)
W5007
2
33
1/2” Split Lock Washer
56
Description
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01.4IB.65120
Figure 22
Vacuum Interrupter Assembly
Drawing (38kV, 2000A)
Detail A - Breaker in Closed Position
0.150” - 0.188”
9
16
7
32
31
28
*29
30
12
14
19
11
13
15
*21
2
25
10
22
17
*26
3
15
4
16
14
24
5
20
6
7
9
23
8
16
*27
*27
18
1
Recommended Renewal Parts and Replacement Procedures
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57
PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
Table F Vacuum Interrupter Assembly Parts List - 2000A
Part Number
Qty
Item
40703G01
1
1
High Voltage Module Assembly
WL35616BP
1
2
VI 38kV 40kA
40773P01
1
3
Front Terminal Clamp
43645P01
1
4
Pushrod, PVAC 38
43646P01
1
5
Regulator, Bias Spring
40093P01
1
6
High Voltage Disc 250MVA
40117P01
1
7
High Voltage Regulator Disc
43641P01
1
8
High Voltage Spacer
43625P01
1
9
High Voltage Pivot
40705P01
1
10
Bottom Bus Support
42078P01
1
11
Lower Bus Connector
42904P01
1
12
Shield, Electrostatic
73780
8
13
5/16” - 18 x 1" Button HD Socket Head Cap Screw S/S
W5005
11
14
5/16” Split Lock Washer
W5205
12
15
5/16” Flat Washer Type A Wide Gold Irridite Finish
W0019
5
16
½" Flat washer, Type AN thick
W0273
1
17
5/16” - 18 x 2” Socket Head Cap Screw
40002P01
1
18
Bias Spring 750MVA Dark Green
40723P01
1
19
Shunt, 1200A
W5206
4
20
3/8 Flat Washer
W1028
2
21
1/2” - 13 x 4” Hex Head Cap Screw
W5006
2
22
3/8” Split Lock washer
W1053
2
23
5/16-18 x 2 Hex Head Bolt
W3006
2
24
5/16” - 18 Hex Nut
W3007
2
25
Hex Nut 3/8 - 16 LC STL, Gold
HexCapScrewInch
4
26
HexCapScrewInch
W3007
2
27
HexNut 3/8 - 16
73783
3
28
5/16” - 18 x 1 ¾" Button Head Socket Cap Screw S/S
W5005
3
29
5/16” Split Lock Washer
W5211
3
30
¼ Flat Washer Type A wide brass
43606G07
1
31
Lower Primary Disc Assy PV38, 2000AMP GE Cluster Style (Consisits of: (1) 43606P60,
(1) 43606G01, (1) 43606P65, (1) 43606P62, (1) W0206, (1) 0.3125, and (2) W1080)
43606G09
1
32
Upper Primary Disc. Assy. PV38, 2000AMP GE Cluster Style (Consists of: (1) 43606P60,
(1) 43606G01, (1) 43606P62, (1) 43606P65, (1) 43606P62, (1) W0206, (1) 0.3125, (2) W1080,
(1) 43606P63, (3) W5006, (3) 73816, (1) 40707P01, and (1) 40706P01)
58
Description
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01.4IB.65120
Table G Primary Current Path
Breaker
Type
Rated
(kV)
Rated
Continuous
Current (Amps)
Vacuum
Interrupter
Assembly
Shunt
Contact
Primary
Disconnecting
Device
38PV40ARM
38
1200
43600G65
40723P01
43606G02
38PV40ARM
38
2000
43600G71
40723P01
43606G07
Figure 23
Primary Current Path
a
b
a. Primary Disconnecting Device
b. Vacuum Interrupter Assembly
Recommended Renewal Parts and Replacement Procedures
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PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
Table H Control Devices
Primary Shunt Trip Coil
Assembly (2)
Control
Voltage
Secondary
Undervoltage
Shunt Trip
Device
Coil Assembly
Assembly (4)
(3)
Charging
Motor
Assembly
Anti-Pump
Relay (5)
Closing Coil
Assembly
3-Cycle
5-Cycle
24VDC
50027G05P
50041G08P
50042G06P
n/a
n/a
n/a
n/a
48VDC
50027G01P
50041G01P
50042G01P
50028G11
50960G06P
RR2BA-USDC48V
43684G05P
125VDC
50027G02P
50041G10P
50042G03P
50028G10
50960G04P
RR2BA-USDC110V
43684G03P
250VDC
50027G03P
50041G03P
50042G04P
n/a
50960G05P
RR2BA-USDC110V
43684G04P
120VAC
50027G01P
50041G05P
50042G01P
n/a
50960G04P
RR2BA-USAC120V
43684G01P
240VAC
50027G06P
50041G06P
50042G02P
n/a
50960G05P
RR2BA-USAC240V
43684G02P
Capacitor Trip
(6)
50027G04P
50041G04P
50042G05P
n/a
n/a
n/a
n/a
Notes:
60
1) One required per circuit breaker if the circuit breaker was originally equipped with this item. All
circuit breakers have a closing coil, primary shunt trip coil, charging motor, and an anti-pump
relay assembly. Secondary shunt trip coils and undervoltage device assemblies are optional
(see notes 2-7).
2) Primary shunt trip coil is available as a 3 cycle and 5 cycle control device. Trip coil assemblies
must only be replaced with the same type as originally supplied.
3) Secondary shunt trip coil cannot be furnished with an undervoltage device assembly.
4) Where furnished, cannot be present with secondary shunt trip coil assembly.
5) For 250VDC applications, a dropping resistor 50747G02P is required in series with the
anti-pump relay assembly.
6) For use with capacitor trip units with 240VAC input. Consult factory for other circuit breaker
ratings.
7) All control devices are available with push-on terminals. Consult factory for control devices
with screw terminals.
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01.4IB.65120
Figure 24
Control Devices
b
a
e
d
c
f
g
a.
b.
c.
d.
e.
f.
g.
Recommended Renewal Parts and Replacement Procedures
Primary Shunt Trip Coil (3 cycle)
Primary Shunt Trip Coil (5 cycle)
Charging Motor Assembly
Closing Coil Assembly
Anti-Pump Relay
Undervoltage Device Assembly
Racking Motor
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PowlVac 38™ ARM Automatic Racking Mechanism 01.4IB.65120
Vacuum Circuit Breaker
Table I Miscellaneous Parts
Description
Catalog Number
Illustration
Auxiliary Switch
Push-On Terminals
102109LN
Screw-On Terminals
102109LP
Ground Connection
40kA
40767G01
Latch Check Switch
BA-2RV2-A2
Motor Cutoff Switch Assembly
50756G03P
62
PowlVac® Lubrication Kit
Powlube-104
Operating Pushrod
43645P01
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Recommended Renewal Parts and Replacement Procedures
01.4IB.65120
PowlVac 38™ ARM Automatic
Racking MechanismVacuum Circuit Breaker
38kV, 1200A & 2000A
April 2015
Powell Electrical Systems, Inc.
Service Division - Houston
PO Box 12818 • Houston, TX • 77217
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©2006 Powell Industries, Inc. • All rights reserved.
Tel: 713.944.6900 • Fax: 713.948.4569
powellind.com
[email protected]
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