7000 Series 7ATB, 7ACTB, 7ADTB
Installation
G, Q, S, & U design 600–4000 A
Manual
Automatic Transfer & Bypass–Isolation Switches
DANGER is used in this manual to warn of a
hazardous situation which, if not avoided, will
result in death or serious injury.
WARNING is used in this manual to warn of a
hazardous situation which, if not avoided, could
result in death or serious injury.
CAUTION is used in this manual to warn of a
hazardous situation which, if not avoided, could
result in minor or moderate injury.
Refer to the outline and wiring drawings provided
with your 7000 Series ATB for all installation and
connection details and accessories.
Refer to Group 5 Controller User’s Guide 381333–126
for ATS status display messages, time delays, pickup
& dropout settings, and adjustments.
An experienced licensed electrician must install the
ATB.
Rating Label
Each 7000 Series ATB contains a rating label to define
the load and fault circuit withstand/closing ratings. Refer
to the label on the Transfer Switch for specific values.
Do not exceed the values on the rating label.
Exceeding the rating can cause personal injury or
serious equipment damage.
Nameplate
The Transfer Switch nameplate includes data for each
specific 7000 Series ATB Use the switch only within
the limits shown on this nameplate. A typical Catalog
Number is shown below with its elements explained:
TABLE OF CONTENTS
section-page
INSTALLATION
Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Power Connections . . . . . . . . . . . . . . . . . . . . 1-2
Engine Starting & Auxiliary Circuits . . . . . . 1-2
Functional Test . . . . . . . . . . . . . . . . . . . . . 1-3, 1-4
TESTING & SERVICE
Transfer Test & Preventive Maintenance . . 2-1
Trouble-Shooting . . . . . . . . . . . . . . . . . . . . . . 2-2
BYPASSING & ISOLATING
Bypassing the ATS . . . . . . . . . . . . . . . . . . . . 3-1
Isolating the ATS . . . . . . . . . . . . . . . . . . . . . . 3-2
Return to Service . . . . . . . . . . . . . . . . . . . 3-4, 3-5
INDEX . . . . . . . . . . . . . . . . . . . . . . . . . back cover
typical 4000 A
50 Hanover Road, Florham Park, New Jersey 07932–1591 USA
Sales or service call 800 800–2726 (ASCO) www.ascopower.com
381333–415 A
ASCO G, Q, S, U 7ATB, 7ACTB, 7ADTB
Installation Manual
Typical 7000 Series G7ATB catalog no. for overlapping neutral, 3 pole, 4000 A, 480 V, in a Type 1 enclosure:
G, Q, S, U
7
A
TB
C
3
4000
N
5
C
Design prefix
letter
Transition Type
A – open
AC – closed
AD – delayed
Neutral
Phase Poles
A – solid
B – switching
C – overlapping
Voltage
Amperes
2 – single Ø
3 – three Ø
blank – none
Note: The ampere rating depends
upon the design (G, Q, S, or U).
600
800
1000
1200
1600
2000
2600
3000
4000
A 115
B 120
C 208
D 220
E 230
F 240
G 277
H 380
Status
Lights
&
Engine
Control
J 400
K 415
L 440
M 460
N 480
P 550
Q 575
R 600
Controller
5 – standard
5X – if
accessories
ordered
Enclosure
C – type 1
F – type 3R
G – type 4
L – type 12
blank – open type
Transfer Control
& Lights
Bypass
Handle
Group 5 Controller
Isolation
Handle
Transfer Switch
Typical G7ATB with lower doors open (transfer switch shown)
page i
ASCO Power Technologies
381333–415 A
SECTION 1
INSTALLATION
ASCO G, Q, S, U 7ATB, 7ACTB, 7ADTB
Installation Manual
The ASCO 7000 Series Automatic Transfer & Bypass–
Isolation Switch (ATB) consists of an upper bypass–isolation switch, a lower transfer switch, a monitoring and
transfer controller, and door–mounted controls. The
ATB is factory wired and tested. Installation requires
removal of the shipping skid then securing the enclosure
to the supporting foundation.
NOTICE
To prevent serious damage, remove three or four
shipping brackets or L–angles from the Transfer
Switch carriage. Do not turn the Isolation Handle
until they are removed!
Remove the Shipping Skid
Open the front lower door and remove the two front lag
screws securing the enclosure to the wood skid. Next
remove the rear lower panel and remove the two rear lag
screws securing the enclosure to the wood skid.
Supporting foundation and mounting
The supporting foundation for the enclosure must be
level and straight. Allow at least 35 inches in front of the
enclosure for draw out of the Transfer Switch. Refer to
the enclosure outline drawing included with the 7000
Series ATB for all mounting details including door
opening space.
If bottom cable entry is used, the foundation must be
prepared so that the conduit stubs are located correctly.
Refer to the appropriate enclosure outline drawing for
specified cable entrance area and location. Provide cable
bending space and clearance to live metal parts. When a
concrete floor is poured, use interlocking conduit spacer
caps or a wood or metal template to maintain proper
conduit alignment.
remove 3 or 4 shipping brackets ( L–angles)
Figure 1-1. 600–3000 A remove shipping brackets.
Mounting
Refer to the enclosure outline drawing furnished with
this switch and mount the 7000 Series ATB according to
the details and instructions shown on the drawing.
remove 2 upper shipping brackets
Remove Shipping Brackets / Angles
from the Transfer Switch
Open the lower front door(s). The Transfer Switch
carriage is secured to the frame for shipment. Remove
the three or four shipping brackets or L–angles:
(1 upper left, 1 upper right, and 2 lower ).
remove 2 lower
shipping brackets
Figure 1-2. 4000 A remove four shipping brackets.
381333–415 A
ASCO Power Technologies
page 1---1
INSTALLATION (continued)
Installation Manual
ASCO G, Q, S, U 7ATB, 7ACTB, 7ADTB
Bus Connections
De–energize the conductors before making any
line or auxiliary circuitry connections. Be sure that
Normal and Emergency line connections are in
proper phase rotation. Place engine generator
starting control in the OFF position. Make sure
engine generator is not in operation.
If bus connection is used, use SAE grade 5 hardware to
connect bus to appropriate terminal plates on bypass
switching device. Wipe off bus surfaces before they are
joined. If bus is dirty, gently clean surfaces with a
non-flammable solvent. Avoid touching cleaned surfaces.
Do not breathe cleaning solvent vapors.
Testing Power Conductors
Do not connect the power conductors to the ATB until
they are tested. Installing power cables in conduit, cable
troughs, and ceiling-suspended hangers often requires
considerable force. The pulling of cables can damage
insulation and stretch or break the conductor’s strands.
For this reason, after the cables are pulled into position,
and before they are connected they should be tested to
verify that they are not defective or have been damaged
during installation.
Use SAE grade 5 hardware and tighten the bolted joints to
the torque specified in Table A.
NOTICE
The reliability of the connection depends
on how clean and how tight the joint is.
Protect the switch from construction grit and metal
chips to prevent malfunction or shortened life of
the ATB switch.
Table A. Tightening torque values for bolted joints.
Bolt Diameter
Recommended
(Grade 5 hardware)
Tightening Torque
in inches
in foot pounds
5/16
12
3/8
20
1/2
50
5/8
95
Connecting Power Conductors
Harnesses
A Wiring Diagram is furnished with the ATB. All wiring
must be made in accordance with the local codes. After
the power cables have been tested, connect them to the
appropriate terminal lugs on the Bypass Switch as shown
on the wiring diagram provided with this ATB. Make
sure that the lugs provided are suitable for use with the
cables being installed. Standard terminal lugs are
solderless screw type and will accept the wire sizes listed
on the drawings provided with the ATB. Be careful when
stripping insulation from conductors; avoid nicking or
ringing the conductor. Remove surface oxides from
conductors by cleaning with a wire brush. Follow
conductor manufacturer’s instructions when aluminum
conductor is used. Apply joint compound to conductor,
then carefully wipe away excess compound. Tighten the
cable lugs to the torque specified on the rating label.
All internal connections are made at the factory. The
bypass switch, transfer switch, and control panel are
joined together by an interconnecting wire harness. The
disconnect plugs are already engaged on enclosed
switches. For open–type switches, the plugs must be
engaged after installation is completed. Align harness
plugs with sockets in the control and push them together
until they are secure.
NOTICE
Controller Ground
A grounding wire must be connected to the controller’s
lower left mounting stud. Because the controller is
mounted on the enclosure door, a conductive strap must
be used between the enclosure and the door. This
connection provides proper grounding which does not
rely upon the door hinges.
Engine Starting Contacts
and Auxiliary Circuits
NOTICE
Be sure that the Normal and Emergency power
connections are in proper phase rotation.
page 1---2
The engine control contact signal connections and
auxiliary circuits are located on terminal block TB as
shown on the Wiring Diagram provided with the ATB.
Connect the signal wires to the appropriate terminals.
ASCO Power Technologies
381333–415 A
INSTALLATION (continued)
ASCO G, Q, S, U 7ATB, 7ACTB, 7ADTB
Installation Manual
Close the normal source circuit
breaker. The Transfer Switch
1 Connected To Normal and the
Normal Source Accepted lights
should come on.
Use an accurate voltmeter to
check phase to phase and
2 phase to neutral voltages present at the transfer switch normal
source terminals.
observe
these
lights
Close the emergency source
circuit breaker. Turn the Engine
Control switch to Run to start
3 the generator. The Transfer
Switch Connected To Normal &
Emergency Source Accepted
lights should come on.
Figure 1-3. Standard controls and indicators.
Functional Test
Read all instructions on the Wiring Diagrams and labels
affixed to the ATB. Note the control features that are
provided and review their operation before proceeding.
After installing the ATB check the following:
– Bypass Handle should be in the OPEN position.
– Isolation Handle should be in the CLOSED position.
– Transfer switch should be in NORMAL position.
(For ACTB and ADTB the CN transfer switch should be
CLOSED and the CE transfer switch should be OPEN).
If handles are not in correct positions, follow instructions
for Bypassing and Isolating the automatic transfer switch
in Section 3. Do not force the handles. Electrical
interlocks prevent a wrong sequence of operation.
Use a phase rotation meter to
check phase rotation of emer5
gency source; it must be the
same as the normal source.
A B C
Turn Engine Control switch to
Auto to stop the generator. The
Emergency Source Accepted
6 light should go off. Then put the
starting control selector switch
(on generator set) in automatic
position. Close enclosure door.
2 – Electrical Operation
This procedure checks electrical operation of the ATS.
1 – Voltage Checks
First check nameplate on transfer switch; rated voltage
must be the same as normal and emergency line voltages.
Use extreme caution when using a meter to
measure voltages. Do not touch power terminals;
shock, burns, or death could result!
Perform steps 1–6 at the right. Observe the status lights.
See Figure 1–3.
 Black square means light is on.
 White square means light is off.
* If necessary, adjust voltage regulator on generator per the
manufacturer’s recommendations. The ATB will respond only to
rated voltage specified on the nameplate.
Now continue to 2 – Electrical Operation.
381333–415 A
Use an accurate voltmeter to
check phase to phase and
4 phase to neutral voltages present at the transfer switch emergency source terminals.*
Be sure to close the enclosure doors before
proceeding to prevent person injury in case of
electrical system fault.
Transfer Test
The ATS should be bypassed and isolated. Follow
instructions for Bypassing and Isolating the automatic
transfer switch in Section 3. Both normal and emergency
sources must be available and the emergency source
generator (if used) must be capable of being started; put
engine starting control in automatic position. The
Transfer Switch Connected to Normal light and the Normal
Source Accepted light should be on.
ASCO Power Technologies
page 1---3
INSTALLATION (continued)
Installation Manual
ASCO G, Q, S, U 7ATB, 7ACTB, 7ADTB
7ACTB alarm lights
(see troubleshooting)
7ACTB buttons
7ADTB light is
on when load is
disconnected
observe
these
lights
operate
this switch
Figure 1-4. Standard controls and indicators.
Figure 1-5. 7ACTB controls.
The Transfer Switch Connected to
1 Normal and Normal Source Accepted lights should be on.
Figure 1-6.
7ADTB controls
Load
Disconnect
Active
(Transfer Test continued from page 1–3)
1.
Turn the Isolation Handle counterclockwise
(approximately 12 turns) until the window shows
TEST position.
NOTE: The engine generator may be signalled
to start while turning the Isolation Handle. If
emergency source is available, the ATS may
operate to the emergency position. If it does,
operate Retransfer Delay Bypass switch.
2.
Perform steps 1–5 at right. Observe the status lights.
 Black square means light is on.
 White square means light is off.
7ACTB
The load is transferred via overlap (closed) transition.
Transfer switch CE closes, then transfer switch CN
opens. The operation is reversed for retransfer back
to normal. If you do not want closed–transition
transfer, press the Closed Transition Bypass button
(Figure 1–5) while the controller display shows
Waiting for In–Sync. This action causes open–transition (momentary load interruption) transfer to the
opposite source, if conditions permit.
7ADTB
The load is disconnected and light (Figure 1–6) comes
on during the delayed–transition transfer delay.
3.
Turn the Isolation Handle clockwise (approximately 12
turns) to the CONN (connected) position.
4.
Push in the Bypass Handle and turn it counterclockwise until the OPEN indicator shows green.
page 1---4
Turn and hold Transfer Control
switch clockwise to Transfer Test
until the engine starts and runs
2
(within 15 sec.). The Emergency
Source Accepted light should
come on.
Transfer switch will operate to the
Emergency position after Feature
2B time delay. The Transfer
Switch Connected to Emergency
3 light should come on and the
Transfer Switch Connected to
Normal light should go off
(7ACTB you might see and hear
the brief overlap transfer).
Transfer switch will operate back
to Normal position after Feature
3A time delay. For immediate
retransfer turn Transfer Control
counterclockwise to Retransfer
4
Delay Bypass. The Transfer
Switch Connected To Normal light
should come on; Transfer Switch
Connected to Emergency light
should go off.
The engine–generator will stop
after the Feature 2E time delay
5 (unloaded running engine cooldown). The Emergency Source
Accepted light should go off.
Load
Disconnect
Active
Load
Disconnect
Active
Load
Disconnect
Active
Load
Disconnect
Active
This completes the Functional Test of the ATB.
ASCO Power Technologies
381333–415 A
SECTION 2
TESTING & SERVICE
ASCO G, Q, S, U 7ATB, 7ACTB, 7ADTB
Installation Manual
TRANSFER TEST
REPLACEMENT PARTS
Test the Automatic Transfer Switch portion of the 7000
Series ATB at least once a month. This procedure checks
the electrical operation of the Transfer Switch and
Controller. Turn the Engine Control switch to Auto and
put the engine–generator starting control (at the
engine–generator set) in automatic mode.
In the test the generator will start, the load will be
transferred to the Emergency source, then back to the
Normal source. An interruption to the load will occur,
unless the Transfer Switch contacts are bypassed before the
test. See pages 3–1 and 3–2 for bypassing and isolating
instructions if no interruption of load is required.
Replacement parts are available in kit form. When
ordering parts provide the Serial No., Bill of Material
No. (BOM), and Catalog No. from the transfer switch
nameplate. For service call ASCO Services at
1–800–800–2726; you will be put in contact with your
local ASI office.
MANUAL LOAD TRANSFER
This procedure manually transfers load to other source if
the Transfer Switch or Control Panel are out of service.
Close enclosure doors to prevent personal
injury in case of electrical system fault.
Be sure to close the enclosure doors before
proceeding to prevent person injury in case of
electrical system fault.
Perform the Electrical Operation – Transfer Test procedure on pages 1–3 and 1–4.
PREVENTIVE MAINTENANCE
1. Be sure that the Bypass Handle is CLOSED on
either Emergency or Normal (see page 3–1).
2. Be sure that the Isolation Handle is in the TEST or
ISOLATE position (see page 3–2).
3. Turn the Bypass Handle counterclockwise to OPEN
the Bypass Switch. Then Bypass to the other source
(see page 3–1).
Reasonable care in preventive maintenance will insure high
reliability and long life for the 7000 Series ATB. An annual
preventive maintenance program is recommended.
ASCO Services, Inc. (ASI) is ASCO Power
Technologies’ national service organization. ASI
can be contacted at 1–800–800–2726 for information on preventive maintenance agreements.
Checklist for Yearly Inspection
Bypass and isolate the Transfer Switch before
using the maintenance handle! See pages 3–1
and 3–2. Remove the hub and handle after using
them and store on frame.
for 7ATB
Hazardous voltage capable of causing shock,
burns, or death is used in this switch.
Deenergize both Normal – Emergency power
sources before performing inspections!
 Clean the ATS enclosure. Brush and vacuum away
any excessive dust accumulation. Remove any
moisture with a clean cloth.
 Check the transfer switch contacts. Remove
transfer switch barriers and check the condition of
the contacts. Replace contacts when pitted or worn
excessively. Reinstall the barriers carefully.
 Maintain transfer switch lubrication. If switch is
subjected to severe dust or abnormal operating
conditions, renew factory lubrication on all
movements and linkages. Relubricate solenoid
operator if TS coil is replaced. Don’t use oil; order
lubrication kit 75-100.
 Check all cable connections & retighten them.
381333–415 A
MAINTENANCE HANDLE
Turn counterclockwise
to Emergency.
Turn clockwise
to Normal.
slide hub
onto shaft
for 7ACTB & 7ADTB
slide hub onto
shaft & insert pin
Pull out shaft to operate
Emergency contacts.
insert
handle
into hole
Grasp
handle
firmly
Turn counterclockwise
to OPEN contacts.
Turn clockwise to
CLOSE contacts.
Push in shaft to operate
Normal contacts.
Figure 2-1. Maintenance handle and hub.
ASCO Power Technologies
page 2---1
TESTING & SERVICE (continued)
Installation Manual
ASCO G, Q, S, U 7ATB, 7ACTB, 7ADTB
TROUBLESHOOTING
Note any optional accessories that may be furnished on
the ATB and review their operation. Refer to any
separate drawings and/or instructions that may be packed
with the ATB.
Table B. Trouble-Shooting Checks.
PROBLEM
Engine–generator set does
not start when the Transfer
Control switch is turned and
held in Transfer Test position
or when normal source fails.
Hazardous voltage capable of causing shock,
burns, or death is used in this switch.
Do not touch the power or load terminals
of the bypass switch or transfer switch!
CHECK IN NUMERICAL SEQUENCE
1 OPERATION
2 GEN-SET
Hold Transfer Test switch 15
Starting control must be in the
seconds or the outage must
automatic position. Batteries
be long enough to allow for
must be charged and
Feature 1C time delay plus
connected. Check wiring to
engine cranking and starting. engine starting contacts.
3 VOLTAGE
–
Transfer switch does not
transfer the load to the
emergency source after the
engine–generator set starts.
Wait for Feature 2B time delay Generator output circuit
breaker must be closed.
to time out.
Generator frequency must be
at least 95% of nominal (57 Hz
for a 60 Hz system.) *
Voltmeter should read at least
90% of nominal phase to
phase voltage between
terminals EA and EC (or EL1
and EL2 for 2 pole switches)*
Transfer switch does not
transfer the load to normal
source when normal returns
or when the Transfer Control
switch is released.
Wait for Feature 3A time delay
to time out.
Voltmeter should read at least
90% of nominal phase to
phase voltage between
terminals NB and NC, NC and
NA, and NA and NB (or NL1
and NL2 for 2 pole switches).
Gen. does not stop after load
retransfer to normal source.
Wait for Feature 2E time delay Starting control must be in the
to time out.
automatic position.
7ACTB
Failure to Synchronize
light comes on.
Conditions of Normal or Emergency Sources not suitable for closed transition transfer.
Recheck voltage and frequency of both sources. Press Alarm Reset pushbutton.
7ACTB
Extended Parallel Time
light comes on.
CN and CE contacts are closed longer than setting in the controller. Open the disconnected
source circuit breaker, then call your nearest ASCO Service Center for assistance.
7ACTB
TS Locked Out
light comes on.
Transfer lockout operation has occured; transfer switch is disabled from automatic operation.
Open the disconnected source circuit breaker, then call your nearest ASI for assistance.
7ADTB
Load Disconnect Active light
comes on.
Delayed transition transfer operation. If load is disconnected longer than the setting in Group 5
controller (see User’s Guide 381333–126), then contact ASI for assistance.
–
–
* These are factory settings. Refer to Controller User’s Guide.
If the problem is isolated to circuits on the controller or the transfer switch, call your local ASCO Power Technologies sales
office or ASI at 1–800–800–2726. Furnish the Serial No. and Catalog No. from the transfer switch nameplate.
page 2---2
ASCO Power Technologies
381333–415 A
SECTION 3 BYPASSING & ISOLATING
ASCO G, Q, S, U 7ATB, 7ACTB, 7ADTB
Installation Manual
BYPASSING THE ATS*
NOTICE
This procedure explains how to Bypass the closed
automatic transfer switch contacts. Bypassing is required
before the ATS can be tested or isolated. The Bypass
Handle must be in the OPEN position (green indicator)
and the Isolation Handle must be in the CLOSED
position (window). See Figures 3–1, 3–2, and 3–3.
You can only bypass to the same source that the
Transfer Switch is connected. Solenoid interlock
prevents incorrect operation.
1.
2.
Observe which Transfer Switch Connected To light is
on (Normal or Emergency) on the door. This is the
position of the automatic transfer switch.
Bypass to the same source as connected to transfer
switch as follows (select Normal or Emergency).
Indicator shows:
Indicator shows:
yellow  EMERGENCY CLOSED
when ATS is bypassed to Emergency
or
green  OPEN when the
ATS is not bypassed.
yellow  NORMAL CLOSED when
ATS is bypassed to Normal Source.
To Bypass Normal push in handle
all the way & turn it clockwise.*
To Bypass Emergency pull out handle all the way & turn it clockwise.*
Figure 3–1. Bypass Handle and position indicators.
To Bypass Normal Source*
To Bypass Emergency Source*
(Load connected to Normal Source)
The Transfer Switch Connected To Normal light is on and
Transfer Switch Connected To Emergency light is off.
(Load connected to Emergency Source)
The Transfer Switch Connected To Emergency light is on
and Transfer Switch Connected To Normal light is off.
Push in* the Bypass Handle all the way, then turn it
clockwise until Bypass Switch Position shows CLOSED on
NORMAL (yellow indicator). The red light Unit Not In
Automatic will flash.
Pull out* the Bypass Handle all the way, then turn it
clockwise until Bypass Switch Position shows CLOSED on
EMERGENCY (yellow indicator). The red light Unit Not
In Automatic will flash.
Push in
Bypass
Handle
&
turn it
clockwise.
Bypass Switch
E
L
Pull out
Bypass
Handle
&
turn it
clockwise.
Bypass Switch
E
L
N
N
ATS
Figure 3–2. Bypass to Normal.
ATS
Figure 3–3. Bypass to Emergency.
The automatic transfer switch can now be put in the TEST or OPEN position. See ISOLATING on page 3–2.
* NOTE: When Accessory 66A (reversed Normal & Emergency connections) is specified,
the handle push–pull operation is reversed. Follow instructions on the door.
381333–415 A
ASCO Power Technologies
page 3---1
Installation Manual
BYPASSING & ISOLATING (continued)
ASCO G, Q, S, U 7ATB, 7ACTB, 7ADTB
ISOLATING THE ATS
Isolating is required before any service work can be
performed on the automatic transfer switch (ATS). Refer
to Figures 3–4, 3–5, 3–6, 3–7a, and 3–7b.
position
window
CONN
TEST
ISOLATE
1. Bypass the closed automatic transfer switch contacts.
See BYPASSING on page 3–1.
NOTICE
unfold
crank
Align the position indicator. Do not leave
the handle in an intermediate position.
2. Turn the Isolation Handle counterclockwise (approx. 16
turns, approx. 12 turns for 4000A) until window shows
TEST. The ATS can be tested now without load
interruption (see page 2–1).
Bypass Switch
E
Turn crank
counterclockwise
until
window
shows
TEST.
Figure 3–4.
CONNECTED to
TEST position.
L
counterclockwise – draws out transfer switch
Figure 3–6. Isolation Handle.
NOTICE
In the TEST position the transfer switch solenoid
operator circuit is energized through secondary
disconnect contacts.
Hazardous voltage capable of causing electrical
shock, burns, or death; do not touch any control
circuit terminals.
N
Automatic Transfer Switch
3. Continue turning the Isolation Handle counterclockwise (approx. 7 turns, approx. 8 turns for 4000 A) until
the window shows ISOLATE.
Bypass Switch
E
Turn crank
counterclockwise
until
window
shows
ISOLATE.
Figure 3–5.
TEST to
ISOLATE
position.
L
N
Automatic Transfer Switch
4. Open the lower enclosure doors(s). Pull out the side
rail carriage. On 4000 A extend two support legs. See
Figures 3–7a and 3–7b. Then roll out the transfer
switch. It can be safely inspected in this position.
The transfer switch can also be removed for easier
maintenance operations.
page 3---2
Figure 3–7a. 600–3000 A transfer switch
isolated and pulled out for inspection.
See page 2–1 for maintenance handle use. Lifting yokes
are available to facilitate lifting transfer switch by using
an overhead crane or similar equipment.
600–3000 A transfer switches weigh 350---450 lbs;
use lifting yoke kit 607064 or other device capable
of lifting this weight to avoid personal injury or
equipment damage.
ASCO Power Technologies
Continued on next page
381333–415 A
BYPASSING & ISOLATING (continued)
ASCO G, Q, S, U 7ATB, 7ACTB, 7ADTB
Installation Manual
grasp two handles
locking pin
with clevis pin
rail support
carriage
left support leg
locking pin
with clevis pin
adjust length to touch floor
right support leg
4000 A transfer switch draw–out procedure
adjust length to touch floor
1. Bypass and Isolate the ATS, then open both lower doors.
2. Pull out the rail support carriage all the way.
3. Remove left & right clevis and locking pins, drop two support legs, reinstall locking
and clevis pins (to lock in place), and adjust both leg lengths to extend to the floor.
4. Stand directly in front of transfer switch. Grasp both handles, and pull straight out
(detents on the rails require high initial force to overcome resistance).
Figure 3–7b. 4000 A transfer switch isolated and pulled out for inspection.
For the 4000 A transfer switch, to avoid personal
injury and equipment damage, two support legs
must be extended as shown in Figure 3–7b.
Substantial initial force is required to pull out the
transfer switch (there are detents on rail).
381333–415 A
The 4000 A transfer switch weighs approx. 600 lb;
use lifting yoke 835745–001 or other device
capable of lifting this weight to avoid personal
injury or equipment damage.
ASCO Power Technologies
page 3---3
Installation Manual
BYPASSING & ISOLATING (continued)
ASCO G, Q, S, U 7ATB, 7ACTB, 7ADTB
RETURN TO SERVICE
NOTICE
This procedure explains how to return the automatic
transfer switch (ATS) to service after inspection and
maintenance. Observe the Bypass Switch Position
indicator and lights). Refer to Figures 3–7 through 3–10.
Solenoid interlock prevents closing the isolation
contacts until the ATS is in the same position as
the Bypass Switch.
1. Slide the transfer switch (ATS) into the enclosure
(isolation contacts facing inward) until its crank pins
engage the latch plates on both sides. Substantial force
is required to overcome detents on the rails. Next push
in side rail carriage. On 4000 A first retract the two
legs and lock them in place. See Figures 3–7a and
3–7b. Then close enclosure door(s).
3. Observe which Bypass Switch Position indicator is
black (NORMAL or EMERGENCY) at Bypass Switch
Handle. This shows the source connected to the load.
4. Observe which Transfer Switch Connected To light is
on (Normal or Emergency) on the door. This is the
position of the Transfer Switch. If it is not in the
same position as the Bypass Handle change the
position of the Transfer Switch as follows:
To change the position of transfer switch
Close the enclosure door to prevent personal
injury in case of electrical system fault.
NOTICE
Align the position indicator. Do not leave
the handle in an intermediate position.
position
window
CONN
TEST
ISOLATE
Operate to NORMAL Operateto EMERGENCY
Turn Transfer Control Turn Transfer Control
switch to Retransfer
switch to Transfer Test
Delay Bypass.
(hold 15 seconds).*
Connected To Normal Connected To Emergency
light should come on. light should comes on.
* If Feature 2B time delay is used, there will be a delay
before transfer to Emergency.
NOTICE
With Normal available, the ATS will not stay in the
emergency position unless Feature 3A time delay
is used (at least 30 seconds).
unfold
crank
clockwise – draws in the Transfer Switch
Figure 3–8. Isolation Handle.
2. Turn the Isolation Handle clockwise (approx. 7 turns,
approx. 8 turns for 4000 A) until the window shows
TEST. The ATS can be tested now without load
interruption (see page 2–1).
Bypass Switch
Turn crank
clockwise
until
window
shows
TEST.
5. When the transfer switch is in the same position as
the Bypass Switch handle, continue turning the
Isolation Handle clockwise (approx. 16 turns, approx.
12 turns for 4000 A) until the window shows CONN
(connected).
Bypass Switch
E
ATS
Figure 3–9. ISOLATE to TEST position.
E
L
L
N
page 3---4
Do not close the isolation contacts unless the
Transfer Switch (ATS) and Bypass Switch are in
the same position!
Turn crank
clockwise
until window
shows
CONN
(connected).
N
ATS
Figure 3–10. TEST to CONNECTED position.
Continued on next page
ASCO Power Technologies
381333–415 A
BYPASSING & ISOLATING (continued)
ASCO G, Q, S, U 7ATB, 7ACTB, 7ADTB
RETURN TO SERVICE continued*
This procedure explains how to return the Bypass Switch
Handle to the OPEN position. The Bypass Handle must
be in the CLOSED position (yellow indicator on NORMAL
or EMERGENCY) and the Isolation Handle must be in the
TEST position (window). If the handles are not in these
positions, refer to Return to Service on page 3–3. See
Figures 3–11, 3–12, and 3–13.
Installation Manual
NOTICE
You can only bypass to the same source that the
ATS is connected. Solenoid interlock prevents
incorrect operation.
1
2
Observe which Bypass Switch Position indicator is
yellow (NORMAL or EMERGENCY) at the Bypass
Switch Handle. This indicates the source connected
to the load.
Un–Bypass to same source as the Bypass Switch
Position as follows (select Normal or Emergency).
Indicator shows:
yellow  EMERGENCY CLOSED
when ATS is bypassed to Emergency
or
Indicator shows:
yellow  NORMAL when ATS is
bypassed to Normal Source.
green  OPEN when the
ATS is not bypassed.
To un–Bypass Emergency pull out
handle all the way & turn it
counterclockwise.*
To un–Bypass Normal push in handle
all the way & turn it counterclockwise.*
Figure 3–11. Bypass Handle and position indicators.
To Un–Bypass Normal Source*
To Un–Bypass Emergency Source*
(Load connected to Normal Source)
The Transfer Switch Connected To Normal light is on and
Transfer Switch Connected To Emergency light is off.
(Load connected to Emergency Source)
The Transfer Switch Connected To Emergency light is on
and Transfer Switch Connected To Normal light is off.
Push in* the Bypass Handle then turn it counterclockwise
until Bypass Switch Position shows OPEN (green indicator).
The Unit Not in Automatic light should be off.
Pull out* the Bypass Handle then turn it counterclockwise
until Bypass Switch Position shows OPEN (green indicator).
The Unit Not in Automatic light should be off.
Push in
Bypass
Handle
&
turn it
counterclockwise.
Bypass Switch
E
L
Pull out
Bypass
Handle
&
turn it
counterclockwise.
Bypass Switch
E
L
N
N
ATS
ATS
Figure 3–12. Un–Bypass Normal.
Figure 3–13. Un–Bypass Emergency.
The Automatic Closed–Transition Transfer & Bypass–Isolation Switch should be left in this position.
* NOTICE
When Accessory 40*B (reversed Normal & Emergency connections) is specified, the handle push–pull
operation is reversed. Follow instructions on the door.
381333–415 A
ASCO Power Technologies
page 3---5
INDEX
ASCO G, Q, S, U 7ATB, 7ACTB, 7ADTB
A
Installation Manual
H
R
Alarm Reset pushbutton, 1–4, 2–2
harness, 1–2
rating label, cover
ASI is ASCO Services Inc.
customercare@asco.com
800–800–2726(ASCO)
HELP
customercare@asco.com
800–800–2726(ASCO)
removal of shipping angles, 1–1
auxiliary circuits, 1–2
B
bus connections, 1–2
bypassing the ATS, 3–1
I
catalog number, i
cleaning, 2–1
closed–transition transfer, 1–4
connections
line, 1–2
controller
see Controller User’s Guide
381333–126
D
delayed–transition transfer, 1–4
drawout, transfer switch, 3–2, 3–3
E
electrical operation, 1–3, 1–4
Emergency Source Accepted light,
1–3, 1–4
Engine Control selector switch
Auto position, 2–1
engine starting contacts, 1–2
Extended Parallel Time light, 1–4, 2–2
F
Failure to Synchronize light, 1–4, 2–2
installation, 1–1 through 1–4
L
lights, 1–3, 1–4
Load Disconnect Active light, 1–4, 2–2
lubrication, 2–1
M
return to service, 3–4
S
service
ASCO Services, Inc. (ASI), 2–1
customercare@asco.com
800–800–2726(ASCO)
settings
see Controller User’s Guide
381333–126
shipping angles, 1–1
warning, 1–1
shipping skid, 1–1
support legs, 3–3
maintenance, preventive, 2–1
maintenance handle, 2–2
warning, 2–2
manual load transfer, 2–1
warning, 2–2
N
nameplate, cover
Normal Source Accepted light, 1–3
O
operation
electrical, 1–4
manual, 2–2
warning, 2–2
P
T
test, functional, 1–3, 1–4
testing power cables, 1–2
time delays, 2–1
see Controller User’s Guide
TS Locked Out light, 1–4, 2–2
Transfer Control selector switch
Retransfer Delay Bypass, 1–4
Transfer Test, 1–4
Transfer Switch Connected To Emergency light, 1–4
Transfer Switch Connected To
Normal light, 1–4
transfer test, 1–4, 2–1
transfer to emergency, 1–4, 2–1
transfer to normal, 1–4, 2–1
troubleshooting, 2–2
parts, 2–1
foundation, 1–1
phase rotation check, 1–3
frequency, generator, 2–2
preventive maintenance, 2–1
functional test, 1–3, 1–4
problem, 2–2
Printed in U.S.A.
replacement parts, 2–1
inspection, 3–1
isolating the ATS, 3–2
C
removal of shipping skid, 1–1
V
voltage checks, 1–3
voltage, pickup and dropout settings
see Controller User’s Guide
Copyright ASCO Power Technologies, L.P. 2014
381333–415 A