Bul. 140U
Q and M-Frame Circuit Breakers
Instruction Leaflet for Electronic RMS Trip Unit Installation and Operation
Table of Contents
Description
Page
1.O General Information ...............................................
1
1
1.1 Protection ..............................................................
2
2.0 UL Listed Devices ..................................................
2
3.0 Installation .............................................................
2
3.1 Preparation (All Trip Units) .....................................
2
3.2 4-Pole Trip Unit Installation .....................................
3
3.3 Ground Fault Trip Unit Installation ..........................
3
3.3.1 General ..................................................................
3
3.3.2 Installation .............................................................
3.4 3-Pole (Non-Ground Fault) Trip Unit Installation ..... 5
3.5 Final Installation Instructions (All Trip Units) ...........6
6
4.0 Principle of Operation ............................................
7
4.1 General ..................................................................
7
4.2 Overload Trip .........................................................
7
4.3 Short Delay/lnstantaneousTrip ..............................
7
4.4 Ground Fault Protection .........................................
7
5.0 Protection Settings .................................................
7
5.1 General ..................................................................
7
5.2 Short Delay Pick-up Settings .................................
7
5.3 Short Delay Time Settings .....................................
7
5.4 Instantaneous Pickup Setting ................................
7
5.5 Ground Fault Pick-up Setting .................................
8
5.6 Ground Fault Time Settings ...................................
8
6.0 Testing ...................................................................
8
6.1 Functional Field Testing .........................................
6.2 PerformanceTesting
- for Ground Fault Trip Units .... 8
6.2.1 Code Requirements ...............................................
8
9
6.2.2 Standards Requirements .......................................
6.2.3 General Test Instructions .......................................
9
7.0 Rating Plug ..........................................................
12
12
8.0 References ..........................................................
8.1 Q-Frame Molded Case
Circuit Breakers ...................................................
12
12
8.2 Internal Accessories ............................................
A WARNING
A
DEATH, SEVERE PERSONAL INJURY, OR
SUBSTANTIAL PROPERTY DAMAGE CAN RESULT
FROM CONTACT WITH ENERGIZED EQUIPMENT. DO
NOT AlTEMPTTO INSTALL OR PERFORM
MAINTENANCE ON EQUIPMENT WHILE IT IS
ENERGIZED. ALWAYS VERIFY THAT NO VOLTAGE IS
40752-072(2) Effective 6/02
PRESENT BEFORE PROCEEDING
AND ALWAYS FOLLOW GENERALLY ACCEPTED
SAFETY PROCEDURES.
ALLEN-BRADLEY IS NOT LIABLE FOR THE
MISAPPLICATION OR MISINSTALLATION OF ITS
PRODUCTS.
The user is cautioned to observe all recommendations,
warnings, and cautions relating to the safety of personnel
and equipment as well as all general and local health and
safety laws, codes, and procedures.
The recommendations and information contained herein
are based on Allen-Bradley experience and judgement,
but should not be considered to be all-inclusive or covering every application or circumstance which may arise. If
any questions arise, contact Allen-Bradley for further
information or instructions.
Fig. 1
Electronic RMS Trip Unit for 3-Pole Q-Frame &
M Frame Circuit Breaker
1.O GENERAL INFORMATION
1.1 Protection
The Electronic RMS, illustrated in Figure 1, is an electronic trip unit that incorporates a microprocessor-based
custom application specific integrated circuit design for
use with Q-Frame and M Frame Molded Case
Circuit Breakers.
The Electronic RMS Trip Unit provides true RMS current
sensing for proper correlation with thermal characteristics of
conductors and equipment. Interchangeable rating plugs
Page 2
are provided to establish the continuous current rating of
each circuit breaker.
The Electronic RMS Trip Unit is completely self-contained and when the circuit breaker is closed, requires no
external power to operate its protection systems. It
operates from current signal levels and control power
derived through current sensors integrally mounted in the
trip unit.
Electronic RMS Trip Units are suitable for 50/60 Hz AC
applications only. For DC applications, a thermal-magnetic
trip unit should be used.
The Electronic RMS Trip Unit is available in 4 different
types, (see Table 1-1). Each trip unit contains a fixed long
delay time function (adjusted by changing the rating plug),
and may be equipped with a maximum of two phase and
two ground (time-current) adjustments to meet specific
application requirements.The types of adjustments
available for each model include the following:
Adjustment
T
m
1) Short Delay Pick-up
LS
2) Short Delay Pick-up/Short DelayTime
LSI
3) Short Delay Pick-Up/Ground Fault
Pick-up/Ground Fault Time
The installation procedure consists of inspecting and
installing the trip unit and rating plug. To install the trip
unit, perform the following steps.
Note: If required, internal accessory installation
should be done before the circuit breaker is mounted
and connected. Refer to individual accessory instruction leaflets.
Make sure that the trip unit is suitable for the intended
installation by comparing nameplate data with any
existing equipment and system requirements. Inspect the
trip unit for completeness, and check for damage before
installing it in the circuit breaker frame.
Note:Trip unit center retaining screw is captive in the
trip unit conductor; the remaining retaining screws
are supplied with the frame.
To continue installation, proceed to the section applicable
to the trip unit being installed:
LSG
Trip UnitTvpe
4-pole Type Trip Unit
3-pole Ground Fault Trip Unit
3-pole Non-Ground Fault Trip Unit
The Electronic RMS Trip Unit is listed in accordance
with Underwriters Laboratories, Inc. Standard UL489
and satisfies the applicable requirements of the
International Electrotechnical Commission (IEC)
recommendations for molded case circuit breakers.
Section
3.2
3.3
3.4
3.2 4-PoleTrip Unit Installation
Remove the three screws for the left- and right-pole and
fourth pole contact bases (Fig. 3) from the hardware bag.
Place the trip unit and fourth pole current sensor side by
side on a flat surface. (See Fig. 2)
Remove the CAUTION tag from the current sensor
secondary winding leads.
Retaining
Screw
KPlaces)\
Note: Secondary winding connector is not polarized.
Current
Sensor
Retaining
Screw
--Fig. 2
3.1 Preparation (AllTrip Units)
Remove circuit breaker pan-head cover screws, and cover.
2.0 UL LISTED DEVICES
\Trip
3 .O INSTALLATlON
Unit
LWinding
Secondary
Connector
Preliminary Alignment of Trip Unit and Current
Sensor
40752-072(2) Effective 6/02
Plug the current sensor secondary winding connector into
the receptacle in the side of the trip unit. Either polarity is
acceptable.
Note:The two trip unit outer retaining screws and
fourth pole sensor retaining screw may be placed in
the trip unit conductor holes at this time. If preferred,
the 5/16 inch hexagonal-head wrench may be used to
position the screws when the trip unit is in the base.
Position trip unit and fourth pole current sensor in base.
Make sure latch bracket pin is properly seated in slots in
side plates (see Fig. 4). If necessary, push circuit breaker
handle towards the closed position to help seat trip unit.
Page 3
3.3 Ground FaultTrip Unit Installation
3.3.1 General
-Contact
Base
-Load
Copper
Fig. 3
Electronic RMS Ground Fault Trip Units detect ground
fault currents through Residual Sensing.They are not
designed to use source ground or zero sequence ground
fault sensing methods. If the system neutral is grounded,
but no phase to neutral loads are used, the neutral current
sensor is not necessary. In that case, the white and grey
leads on the trip unit should be cut off before installation.
Contact Bases and Load Copper
LINE END
Side
Plate
Trigger
Trip
Unit and
Current
Sensor
Retaining
Screws
Fourth
Unit
Fig. 4
LOAD END
nh
.P-.-
Current
Sensor
Trip Unit Installed in Circuit Breaker
a
CAUTION
DO NOT EXCEED A TORQUE OF 12LB-FT
(16.27 N.M). EXCESSIVE TORQUING WILL SHEAR
SCREWS.
FAILURE TO APPLY THE REQUIRED TORQUE MAY
LEAD TO EXCESSIVE HEATING AND CAUSE
NUISANCETRIPPING OFTHE CIRCUIT BREAKER.
Screw in and tighten three trip unit retaining screws
(center first) and the screw for the fourth pole current
sensor.Torque to 12 Ib-ft (16.27 N.m) (see Fig. 4).
Finish installation of the 4-pole Trip Unit by following the
instructions in Section 3.5.
40752-072(2) Effective 6/02
Ground fault trip units are supplied from the factory with a
wire harness with pigtail lead connections for a neutral
current sensor (white and grey wires) and a ground fault
alarm relay (yellow and green wires). A neutral current
sensor is provided with each trip unit, and the ground fault
alarm relay is ordered and shipped separately if required.
If the alarm relay is not required, the green and yellow
leads should be cut off before the trip unit is installed in
the breaker.
If the system neutral is grounded and phase to neutral
loads are used, then the neutral current sensor (see Fig. 5)
must be used. It should be connected to the breaker
according to the diagram in Fig. 6. It has the same turns
ratio as the phase current sensors in the trip unit.
Note:The polarity of the sensor connections is
critical. Always observe the polarity markings on the
installation drawings.The polarity markings are
identified as white dots on the transformer.To insure
correct ground fault equipment performance, conduct
field tests to comply with National Electric Code
requirements under article 230-95(C). See Section 6.2
for testing instructions.
The optional “Internal Accessories” listed in Section 8.2
are available for installation in a Electronic RMS Ground
Fault Trip Unit.These items, if required, must be ordered
separately.
3.3.2 Installation
Plug the wire harness supplied for the neutral current
sensor and ground fault alarm relay (white, grey, yellow
and green wires) into the connector located in the right
pole of the trip unit. With the correct polarity the harness
should snap into place. Do not force the harness into the
connector with the wrong polarity.
Remove trip unit outer pole screws and red plastic
washers from the breaker frame. Discard red plastic
washers (fig. 7). For the M-frame, also remove the load
end trip unit mounting screws from the frame
(fig. 7a).
Page 4
Fig. 5
SOURCE
- COVER SCREWS
TORQUE
20-22
9
9
LOAD
.Aux~Iiary switch shown m the "Breaker Canlacis Open'' p m i l m n
Fig. 6
40752-072(2) Effective 6/02
Fig. 7a
M-Frame Trip Unit Installation
-1b
Page 5
Position trip unit in base. Make sure latch bracket pin is
properly seated in slots in side plates (see Fig. 8). If
necessary, move latch toward load end of circuit breaker
to seat trip unit.
Screw in and tighten three trip unit retaining screws
(centerfirst).Torque to 12 Ib-ft (16.27 N.m) (see Fig. 8).
A CAUTION
A
DO NOT EXCEED A TORQUE OF 12 LB-FT
(16.27 n.m.) EXCESSIVE TORQUING WILL SHEAR
SCREWS.
Lefl
Contact
Base
Fig. 7
FAILURE TO APPLY THE REQUIRED TORQUE MAY
LEADTO EXCESSIVE HEATING AND CAUSE
NUISANCE TRIPPING OF THE CIRCUIT BREAKER.
Right
Contact
Base
For an M-Frame, also screw in and torque the load end
screws to 6-8 Ib-ft. (8.14-10.85 N.m.).
Left- and Right-Pole Contact Bases
3.4 3-Pole (Non-Ground FauIt)Trip Unit Installation
Circuit
Breaker
Handle
Remove trip unit outer pole screws and red plastic
washers from the breaker frame. Discard red plastic
washers (fig. 7). For the M-Frame, also remove the load
end trip unit mounting screws from the frame
(fig. 7a).
Latch
NOTE: The two trip unit outer retaining screws may
be placed in the trip unit conductor holes at this time.
If preferred, the 5/16 inch hexagonal-head wrench may
be used to position the screws when the trip unit is in
the base.
Position trip unit in base. Make sure latch bracket pin is
properly seated in slots in side plates (see Fig. 8). If
necessary, move latch toward load end of circuit breaker
to seat trip unit.
Screw in and tighten three trip unit retaining screws
(centerfirst).Torque to 12 Ib-ft (16.27 N.m) (see Fig. 8).
Side
Plate
Fig. 8
Trip
Unit
Retaining
Screws
Side
Plate
Trip Unit Installed in Circuit Breaker
Note: The two trip unit outer retaining screws may be
placed in the trip unit conductor holes at this time. If
preferred, the 5/16 inch hexagonal-head wrench may
be used to position the screws when the trip unit is in
the base.
40752-072(2) Effective 6/02
A
CAUTION
DO NOT EXCEED A TORQUE OF 12 LB-FT
(16.27 N.M). EXCESSIVE TORQUING WILL SHEAR
SCREWS.
FAILURE TO APPLY THE REQUIRED TORQUE MAY
LEADTO EXCESSIVE HEATING AND CAUSE
NUISANCE TRIPPING OF THE CIRCUIT BREAKER.
Page 6
For an M-Frame, also screw in and torque the load end
screws to 6-8 Ib-ft. (8.14-10.85 N.m.)
3.5 Final Installation Instructions (All Trip Units)
Install accessory(ies), if required, using the appropriate
instruction leaflet listed in Section 8.2. Where accessories
are not required, install protective barriers supplied with
the trip unit in accessory retaining slots in left- and righthand poles of trip unit and in fourth pole current sensor if
applicable.
Make sure interphase barriers and sliding handle barrier
are in place.
Install circuit breaker covers and pan-head screws as
shown in Fig. 9.
a
until the arrow points to ENGAGED. If an adjustable rating
plug is used, four continuous current settings are possible.
Set the switch marked A, B, C, D to the current rating
desired.
Note: The reverse procedure is used to remove the
rating plug. Turn the Push-to-Trip button to the
remove position.This action will cause the circuit
breaker to trip.Then grasp the lip of the Push-to-Trip
button and gently pull. A small screwdriver placed
under the left edge of the rating plug will assist in
removal.
Reset circuit breaker by moving handle to the reset
position. Move handle to the ON position. Circuit breaker
handle should remain at the ON position.
Press Push-to-Trip button (in rating plug) to check manual
tripping of the circuit breaker.
CAUTION
THE RATING PLUG MECHANICALLY INTERLOCKS
WITH THE TRIP UNIT. IF RATING PLUG IS NOT
CORRECTLY INSTALLED,THE CIRCUIT BREAKER
CANNOT BE RESET OR PLACED IN THE ON
POSITION
Torque 20-22 IN-LB
Trip
Unit
Fourth
Fig. 10
Fig. 9
Cover Screw Installation Positions
Note: Before attempting to install the rating plug, the
arrow in the Push-to-Trip button portion of the plug
must be pointing toward the REMOVE position.This
can be done with a small screwdriver.
Install rating plug. Position the rating plug as shown in Fig.
10. Insert the rating plug in the trip unit.The pins and
plunger must align correctly with the matching receptacles
and slot in the trip unit. After the rating plug is pressed into
position, depress the Push-to-Trip button with a small
screwdriver and turn it clockwise one quarter of a turn
40752-072 (2) Effective 6/02
Installing Rating Plug
4.0 PRINCIPLE OF OPERATION
In open air at 40"C, an Q-Frame circuit breaker with an
Electronic RMS Trip Unit installed will carry continuously
up to 800 amperes without exceeding a 50°C rise at the
terminals. The calibration of the trip unit is insensitive to
ambient temperatures over a range of -20" to +55"C.
However, the trip unit contains thermal temperature
protective circuitry that initiates a trip operation for selfprotection if the internal ambient temperature at the
printed circuit board (PCB) reaches approximately 100°C.
This may occur for open air temperatures above 40°C
with circuit breaker currents near full load.
Page 7
For ambient conditions above 40°C and where the
maximum ampere rating plug has been installed, derating
of the circuit breaker frame should be considered to avoid
exceeding a safe terminal temperature operating range.
Consult Allen-Bradley for recommendations.
4.1 General
The Electronic RMS Trip Unit provides a tripping signal
to the flux transfer shunt trip when current and time delay
settings are exceeded. This is accomplished by employing
the Allen-Bradley custom designed integrated circuit
SpreTMchip,which includes a microcomputer to perform
its numeric and logic functions.
In the Electronic RMS Trip Unit, all required sensing and
tripping power to operate its protection function is derived
from the current sensors in the circuit breaker. The
secondary currents from these sensors provide the
correct input information for the protection functions, as
well as tripping power, whenever the circuit breaker is
carrying current. These current signals develop analog
voltages across the appropriate calibrating resistors.
The microcomputer, in cyclic fashion, repeatedly scans
the voltage values across each calibrating resistor and
enters these values into memory. These data are used to
calculate true RMS current values, which are then repeatedly compared with the protection function settings and
other operating data stored in the memory. The software
program then determines whether to initiate protection
functions, including tripping the breaker through the flux
transfer shunt trip device in the circuit breaker.
4.2 Overload Trip: In accordance with standards requirements, the trip unit initiates a trip of the circuit breaker
within two hours for an overload of 135 percent, and will
trip in less time for higher overload currents.
A “Thermal Memory” effect prevents the breaker from
being re-energized immediately after an overload. A
“cooling off” period of up to 5 minutes is required, which
allows time for cabling to cool off.
4.3 Short Delay/lnstantaneousTrip: For short circuit
conditions that exceed the short delay pick-up settings,
the trip unit initiates a trip after a delay prescribed by the
I2tramp function for trip units with catalog number suffixes
LS, LSG. A flat response time delay action
is provided by trip units with catalog number suffixes LSI,
and LSIG unless the instantaneous (I) setting
is selected.
4.4 Ground Fault Protection: When selected, ground
fault pick-up and time delay settings shown in Table 1-2
allow selective ground fault coordination with other circuit
protection devices.
40752-072(2) Effective 6/02
5.0 PROTECTION SETTINGS
5.1 General
Prior to placing any circuit breaker in operation, each trip
unit protection setting must be set to the values specified
by the engineer responsible for the installation.The
available settings along with the effect of changing the
settings are illustrated in Figures 12-1 to 12-3.
The installed rating plug establishes the maximum
continuous current rating (I,) of the circuit breaker. Short
delay current settings are defined in multiples of ln..,
One to four time and pick-up adjustment settings are
available depending on the particular trip unit purchased.
A rotary switch is provided for each setting. The rotary
switch is adjusted using a small flatblade screwdriver
(Figure 11).
5.2 Short Delay Pick-up Setting
Seven settings are available that range from 2 to 8 (I,) as
shown in Figure 12-1.This feature is included on all
Electronic RMS Trip Units.
5.3 Short DelayTime Settings
For catalog number LS and LSG the short time delay is an
ramp configuration with the actual time delay a
function of the trip current involved.
For catalog number LSI and LSIG the short time delay
is a flat response. Four settings (I,.1, .2, .3 second)
are available (see Figure 12-2). The "I" setting
gives a trip response with no intentional delay
(Instantaneous).
5.4 Instantaneous Pickup Setting
For catalog number LSI and LSIG Instantaneous Pickup
is achieved by setting Short Delay Time to "I"
(Instantaneous.) Short Delay Pickup (see paragraph 5.2)
then becomes Instantaneous Pickup.
5.5 Ground Fault Pick-up Setting
Five settings ranging from 1 through 5 (xlG) are available
(see Figure 12-3) and correspond to the fixed ampere
values listed on the trip unit nameplate and in Table 1.2.
Note:These ampere values are always the same no
matter what rating plug is installed in the circuit
breaker.
Page 8
6.OTESTING
6.1 Functional FieldTesting
5.6 Ground FaultTime Settings
The ground fault time delay is a flat response with four
settings (I, .15, .3, .5second) available (Figure 12-3).The
I setting gives a trip response with no intentional delay
(Instantaneous).This option is available on Catalog Nos.
LSG and LSIG.
A test receptacle is built into each trip unit to allow use of
the STK2 Test Kit. The Test Kit performs a test of the Long
Delay, Short Delay and Ground Fault functions.
6.2 Performance Testing for Ground Fault Trip Units
6.2.1 Code Requirements
The National Electrical Code under Article 230-95-C
requires that any ground-fault protection system be
performance tested when first installed.The test shall be
conducted in accordance with approved instructions
I\
I
Remove-
\
I
I
L T e s t
Jacks
Fig. 1 1
Adjustment Switches and Test Points
5
I Ih
1 Ilh
7@3
5
W
+E
Short Delay Pick-up
(Multiples of Rated Cuirrent)
Short Delay Pickup
(Multiples of Rated Current )1,
Current
Current
Fig. 12-1 Short Delay Trip Current Adjustment and Curve
Details
40752-072(2) Effective 6/02
Fig. 12-2Short Delay Trip Current and Short Delay Trip
TimeAdjustment and Curve Details
Page 9
&
!
(
\
0
0
3
I
8
’*+
I
i
Rating Plug Setting (Amperes)
.-
+
L
2x-Ex 2x-8x 2 x . 8 ~2x-Ex
t
See Fig. 2-7 and Fig. 2-8for
Continuation of Short Time
Instantaneous Portions of Curves
L
Time Ms
Current
Current
Fig. 12-3 Ground Fault Trip Current, and Ground Fault Trip
TimeAdjustments and Curve Details
provided with the equipment. A written record of this test
shall be made and shall be available to the authority
having inspection jurisdiction.
6.2.2 Standards Requirements
As a follow-up to the basic performance requirements
stipulated by the N.E.C. as stated above, UL Standard No.
1053 requires that certain minimum instructions must
accompany each ground fault protection system. These
following statements plus a copy of the test record form
illustrated in Fig. 16 are shipped with each Electronic
RMS Trip Unit.
6.2.3 General Test Instructions
The interconnected system shall be evaluated in accordance with the equipment assembler’s detailed instructions by qualified personnel.
The polarity of the neutral sensor connections (if used)
must agree with equipment assembler’s detailed instructions to avoid improper operations following apparently
correct simulated test operations. Where a question
exists, consult the specifying engineer and/or equipment
assembler.
The grounding points of the system shall be verified to
determine that ground paths do not exist that would
bypass the sensors. The use of high-voltage testers and
resistance bridges may be used.
40752-072(2) Effective 6/02
Fig. 13
OptionalAdjustable Ampere Setting Rating
Plug Used in Electronic RMSTrip Unit
a
WARNING
THERE IS A HAZARD OF ELECTRICAL SHOCK OR
BURN WHENEVER WORKING IN OR AROUND
ELECTRICAL EQUIPMENT. ALWAYSTURN OFF
POWER SUPPLYING BREAKER BEFORE
CONDUCTINGTESTS.
Note: Since the Electronic RMS Trip Units derive
their operating power from the phase currents, and
not from the neutral current, passing current through
the neutral sensor only will not properly test the
ground fault feature.
Using a low voltage (0-24 volt), high current, AC source,
apply a test current of 125% of the Electronic RMS
Ground FaultTrip Unit pick-up setting through one phase
of the circuit breaker, as shown in Fig. 14-1.This should
cause the breaker to trip in less than 1 second, and if an
alarm indicator is supplied, it should operate. Reset the
breaker and the alarm indicator. Repeat the test on the
other two phases.
Page 10
69
voltage
Source
Source
1
Load
i
Nl
Current-Lim iring
Resisto!
(if required1
Fig. 14-1 Connections for Ground Fault Trip Test
Load
Fig. 14-2 Connections for Ground Fault No-Trip Test, with
a Four- Wire System
Voltage
Source
Fig. 15
Current
Limiting
Resistor
(if required)
Fig. 14-3 Connections for Ground Fault No-Trip Test, with
a Three-Wire System
40752-072(2) Effective 6/02
Current Limiting
Resistor
(if required)
Typical Rating Plug
Page 11
GROUND FAULT TEST RECORD FORM
Ground Fault Test Record should be Retained by Those in Charge of the Building's Electrical
Installation in order to be available to the Authority having Jurisdiction.
Test Date
Fig. 16
Circuit
Breaker
Number
Typical Performance Test Record Form
40752-072(2) Effective 6/02
Results
Tested By:
Page 12
If the system is a 4-wire system with a neutral current
sensor, apply the same current as described above
through one phase of the breaker, returning through the
neutral sensor, as shown in Fig. 14-2.The breaker should
not trip, and the alarm indicator, if supplied, should not
operate. Repeat the test on the other two phases.
If the system is a 3-wire system with no neutral current
sensor, apply the same current as described above
through any two phases of the breaker, with the connections exactly as shown in Fig. 14-3.The breaker should
not trip, and the alarm indicator, if supplied, should not
operate. Repeat the test using the other two combinations
of breaker phases.
a
CAUTION
FIELDTESTING SHOULD BE USED FOR
FUNCTIONALTESTING AND NOT FIELD
CALIBRATION OF THE ELECTRONIC RMS GROUND
FAULTTRIP UNIT.
ANY TEMPORARY CONNECTION MADE FORTHE
PURPOSE OF CONDUCTINGTESTS SHOULD BE
RESTOREDTO PROPER OPERATING CONDITIONS
BEFORE RETURNINGTHE BREAKERTO SERVICE.
The results of the test are to be recorded on the test form
provided with the equipment.
7.0 RATING PLUG
The rating plug, as illustrated in Figure 15, is used to
establish the continuous ampere rating of the related
circuit breaker.
40752-072(2) Effective 6/02
For adjustable rating plugs (Table 1-2), the primary
current carrying conductors used with the breaker must
be sized to correspond with the maximum setting of the
rating plug, in accordance with National Electric Code
requirements.
The Long Delay protection function of the trip unit is set at
the rating plug value ((,).The Short Delay and Instantaneous protection functions are set as a multiple of In.The
Ground Fault protection function is independent of In.
Different rating plugs are available (Table 1-2) to match
the desired current rating and type of circuit breaker into
which the trip unit is to be installed.
Complete catalog descriptions of all available rating plugs
are given in the applicable circuit breaker supplementary
instruction leaflets (see Section 8.0).
8.0 REFERENCES
8.1 Q-Frame Molded Case Circuit Breakers
40752-078
Contact AB
Frame Instruction Leaflet
Typical Time-Current Characteristic
curves for L Frame Breakers
8.2 Internal Accessories: The following types of internal
accessories, which mount on the trip unit, are available for
use. The number of the instruction leaflet covering the
installation of each accessory is shown.
..
.
Alarm (Signal)/Lockout (ASL) Switch ...........40752-076
Auxiliary Switch ...........................................
40752-074
ShuntTrip ....................................................
40752-075
Undervoltage Release Mechanism (Handle
Reset ...........................................................
40752-070
Page 13
Trip Unit Functions
Table 1-1. Electronic RMS Trip Units
3 Pole
Electronic RMS Trip Unit type Catalog Numbers
LS
LSI
LSG
LSIG
Long Delay Fixed Ampere
Rating¬ with
Fixed Long Delay
Adjustable ampere
Setting with fixed
Long Delay­
Short Delay Adjustable Short
Delay Pick-up with
Short Delay Time
l2t Ramp
Instant
Ground
Fault
Fourth
Pole
Protection
l
l
l
l
l
l
l
l
l
l
Adjustable Short
Delay Time® with
Adjustable Short
Delay Pick-up, or
l
l
Adjustable
Instantaneous
Pick-up®
Fixed
Instantaneous
(Override)¯
Adjustable Ground
Fault Pick-up with
Adjustable Ground
Fault Time
100% rating for
fourth pole
l
l
l
l
l
l
l
l
60% rating for
fourth pole
Fourth pole
unprotected
¬ Fixed rating plugs available, see Table 1-2
­ Optional four-setting adjustable rating plugs available, see Table 1-2
® Using trip unit with adjustable short delay time (LSI, LSIG), instantaneous pick-up is achieved when the lowest time delay setting
(1) is selected.
¯ A non-adjustable override setting is set at the frame withstand rating.
40752-072(2) Effective 6/02
Page 14
Table 1-2. Electronic RMS Trip Unit Function and Rating Settings
Trio Function
RatinalSettina Descriotion
Ampere Rating
Fixed at 100%
Fixed rating plugs available
Trip Unit
Amoere Ratina
Fixed Rating Plugs
600A
630A
800A
300A, 350A, 400A, 500A, 600A (I,)
300A, 315AO, 350A, 400A, 500A, 600A, 630AO (I,)
400A. 500A. 600A. 700A. 800A (I-!
Trip Unit
Ampere Rating
Adjustable Rating Plugs
600A
630A
800A
300A-400A-500A-600A (I,)
315A-400A-500A-630A (IJO
400A-500A-630A-800A fI I or 400A-500A-600A-800A fI I
Adjustable Long
Delay Pick-up
Short Delay Pick-up
(Adjustable)
In multiples of installed rating plug amperes
(I,) with marks at 2-3-4-5-6-7-8x
Short DelayTime
(Fixed)
IZtramp configuration
Short DelayTime
(Adlustable)
Flat response with time delay settings at
100 ms 200 ms and 300 ms
Instantaneous
Pick-upO
Ground Fault
Pick-up
(Adjustable)
Trip Unit
Ampere Rating
Settings
600A
800A
120A, 240A, 360A, 480A, and 600A
160A, 320A, 480A, 640A, and 800A
Ground Fault Time Delay
Settinas at instantaneous (1). 150ms. 300ms. and 500ms
0 Not UL Listed
O Occurs with short delay time adjustment set at I
40752-072(2) Effective 6/02
Printed in U.S.A./TQC
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