ASCO 7000 SERIES 7ATB, 7ACTB, 7ADTB
Automatic Transfer & Bypass–Isolation Switches
G, Q, S, & U design
Installation Manual
381333-415 A
9/2016
An experienced licensed electrician must install
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.
the ATB.
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:
Nameplate
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.
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.
Catalog Number Identification .................................................................................................................................. 3
Remove the Shipping Skid ....................................................................................................................................... 4
Supporting Foundation and Mounting ...................................................................................................................... 4
Remove Shipping Brackets/Angles from the Transfer Switch .................................................................................. 4
Testing Power Conductors ....................................................................................................................................... 5
Connecting Power Conductors ................................................................................................................................. 5
Bus Connections ...................................................................................................................................................... 5
Functional Test ......................................................................................................................................................... 6
Functional Test – Voltage Checks ............................................................................................................................ 6
Functional Test - -Electrical Operation .................................................................................................................... 6
Testing & Service ...................................................................................................................................................... 8
Transfer Test ............................................................................................................................................................ 8
Replacement Parts ................................................................................................................................................... 8
Manual Load Transfer .............................................................................................................................................. 8
Bypassing the ATS ................................................................................................................................................. 10
To Bypass Normal Source ...................................................................................................................................... 10
To Bypass Emergency Source ............................................................................................................................... 10
Isolating the ATS .................................................................................................................................................... 11
Return to Service .................................................................................................................................................... 13
Index .......................................................................................................................................................................... 15
2 381333-415 B
Page 3
7000 Series ATB, ACTB, ADTB Installation Manual
Catalog Number Identification
Typical 7000 Series G7ATB catalog no. for overlapping neutral, 3 pole, 4000 A, 480 V, in a Type 1 enclosure:
G 07A TB C 3 4000 N 5
Design
prefix
letter
G
Q
S
U
Transition
Type
07A open
7AC closed
7AD delayed
Neutral Phase
A- solid
B- switching
C- overlapping*
blank-none
*Overlapping neutral
not available for
Q, S, & U-designs
Poles
single
2
3 three
Amperes
600
800
1000
1200
1600
2000
2600
3000
Voltage Controller
A 115
B 120
C 208
D 220
E 230
F 240
G 277
H 380
J 400
K 415
L 440
M 460
N 480
P 550
Q 575
R 600
4000
Status
Lights
&
Engine
Control
Bypass
Handle
Transfer Control
5 standard
if
5X
accessories
ordered
& Lights
C
Enclosure
C type 1
F type 3R
G type 4
L type 12
blanc –
open type
Isolation
Handle
Group 5 Controller
Transfer Switch
Typical G7ATB with lower doors open (transfer switch shown)
381333-415 B 3
Page 4
Installation Manual Installation
INSTALLATION
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.
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.
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!
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.
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 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 3 or 4 shipping brackets ( L–angles)
Figure 1. 600–3000 A remove shipping brackets.
remove 2 upper shipping brackets
remove 2 lower
shipping brackets
Figure 2. 4000 A remove four shipping brackets.
4 381333-415 B
Page 5
Installation Installation Manual
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.
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.
Protect the switch from construction grit and
metal chips to prevent malfunction or shortened
life of the ATB switch.
Connecting Power Conductors
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.
Do not breathe cleaning solvent vapors.
Use SAE grade 5 hardware and tighten the
bolted joints to the torque specified in Table A.
The reliability of the connection depends
on how clean and how tight the joint is.
Table A. Tightening torque values for bolted joints.
Bolt Diameter
(Grade 5 hardware)
in inches
5/16 12
3/8 20
1/2 50
5/8 95
Recommended
Tightening Torque
in foot pounds
Harnesses
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.
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
Be sure that the Normal and Emergency power
connections are in proper phase rotation.
381333-415 B 5
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.
Page 6
Installation Manual Installation
1 Close the normal source circuit
breaker. The Transfer Switch
Connected To Normal and the
Normal Source Accepted lights
should come on.
2 Use an accurate voltmeter to
observe
these
lights
Figure 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 (pages 10-12). Do not force the handles. Electrical interlocks prevent a wrong
sequence of operation.
check phase to phase and phase
to neutral voltages present at the
transfer switch normal source
terminals.
3 Close the emergency source
circuit breaker. Turn the Engine
Control switch to Run to start
the generator. The Transfer
Switch Connected To Normal &
Emergency Source Accepted
lights should come on.
4 Use an accurate voltmeter to
check phase to phase and phase
to neutral voltages present at the
transfer switch emergency
source terminals.*
C
B
5 Use a phase rotation meter to
check phase rotation of
emergency source; it must be
the same as the normal source.
6 Turn Engine Control switch to
Auto to stop the generator. The
Emergency Source Accepted
light should go off. Then put the
starting control selector switch
(on generator set) in automatic
position. Close enclosure door.
A
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 voltage.
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 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.
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 (pages 10-12). 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.
6 381333-415 B
Page 7
Installation Installation Manual
7ACTB alarm lights
(see troubleshooting)
7ACTB buttons
7ADTB light is
on when load is
disconnected
observe
these
lights
Figure 5. 7ACTB controls. Figure 6.
operate
this switch
7ADTB controls
1 The Transfer Switch Connected to
Normal and Normal Source
Accepted lights should be on.
Load
Disconnect
Active
Figure 4. Standard controls and indicators.
(Transfer Test continued from page 6)
1. Turn the Isolation Handle counterclockwise
(approximately 12 turns) until the window shows
TEST position.
NOTE: The engine generator may be signaled 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 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 6) comes
on during the delayed–transition transfer delay.
3. Turn the Isolation Handle clockwise
(approximately 12 turns) to the CONN (connected)
position.
2 Turn and hold Transfer Control
switch clockwise to Transfer Test
until the engine starts and runs
(within 15 sec.). The Emergency Source Accepted light should
come on.
3 Transfer switch will operate to the
Emergency position after Feature
2B time delay. The Transfer Switch Connected to Emergency
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).
4 Transfer switch will operate back
to Normal position after Feature
3A time delay. For immediate
retransfer turn Transfer Control
counterclockwise to Retransfer
Delay Bypass. The Transfer
Switch Connected To Normal light should come on; Transfer Switch
Connected to Emergency light
should go off.
5 The engine–generator will stop
after the Feature 2E time delay
(unloaded running engine
cooldown). The Emergency Source Accepted light should go
off.
This completes the Functional Test of the ATB.
Load
Disconnect
Active
Load
Disconnect
Active
Load
Disconnect
Active
Load
Disconnect
Active
4. Push in the Bypass Handle and turn it
counterclockwise until the OPEN indicator shows
green.
381333-415 B 7
Page 8
Installation Manual Testing & Service
TESTING & SERVICE
TRANSFER TEST
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 10 and 1 for bypassing
and isolating instructions if no interruption of load is
required.
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 6 and 7.
PREVENTIVE MAINTENANCE
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. is ASCO Power Technologies’
national service organization. They can be contacted
at 1-800-800-2726 for information on preventive
maintenance agreements
YEARLY INSPECTION
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. Re-lubricate solenoid
operator if TS coil is replaced. Don’t use oil; order
lubrication kit 75-100.
Check all cable connections & retighten them.
REPLACEMENT PARTS
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.
1. Be sure that the Bypass Handle is CLOSED on
either Emergency or Normal (see page 10).
2. Be sure that the Isolation Handle is in the TEST or
ISOLATE position (see page 11).
3. Turn the Bypass Handle counterclockwise to OPEN
the Bypass Switch. Then Bypass to the other
source (see page 10).
MAINTENANCE HANDLE
Bypass and isolate the Transfer Switch before
using the maintenance handle! See pages 10
and 11. Remove the hub and handle after using
them and store on frame.
for 7ATB
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.
Turn counterclockwise
to OPEN contacts.
Turn clockwise to
CLOSE contacts.
Push in
Normal contacts.
Figure 7. Maintenance handle and hub.
insert
handle
into hole
Grasp
handle
firmly
shaft to operate
8 381333-415 B
Page 9
Troubleshooting Installation Manual
g
y
)
g
g
g
A
g
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 CHECK IN NUMERICAL SEQUENCE
1 OPERATION 2 GEN-SET 3 VOLTAGE
Engine–generator set does
not start when the
Transfer Control switch is
turned and held in Transfer Test position or when
normal source fails.
Transfer switch does not
transfer the load to the
emergency source after
the engine–generator set
starts.
Transfer switch does not
transfer the load to normal
source when normal
returns or when the
Transfer Control switch is
released.
Gen. does not stop after
load retransfer to normal
source.
7ACTB
Failure to Synchronize
li
ht comes on.
7ACTB
Extended Parallel Time
li
ht comes on.
7ACTB
TS Locked Out
li
ht comes on.
7ADTB
Load Disconnect Active
li
ht comes on.
Hold Transfer Test switch
15 seconds or the outage
must be long enough to
allow for Feature 1C time
delay plus engine cranking
and startin
Wait for Feature 2B time
delay to time out.
Wait for Feature 3A time
delay to time out.
Wait for Feature 2E time
delay to time out.
Conditions of Normal or Emergency Sources not suitable for closed transition
transfer.
Recheck voltage and frequency of both sources. Press Alarm Reset pushbutton.
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.
Transfer lockout operation has occurred; transfer switch is disabled from automatic
operation. Open the disconnected source circuit breaker, then call your nearest
SCO Power Services, Inc for assistance.
Delayed transition transfer operation. If load is disconnected longer than the setting
in Group 5 controller (see User’s Guide 381333–126), then contact ASCO Power
Services, Inc for assistance.
.
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!
Starting control must be in
the automatic position.
Batteries must be charged
and connected. Check
wiring to engine starting
contacts.
Generator output circuit
breaker must be closed.
Generator frequency must
be at least 95% of nominal
(57 Hz for a 60 Hz
s
stem.) *
– Voltmeter should read at
Starting control must be in
the automatic position.
–
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)*
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
.
–
* 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 ASCO Power Services, Inc at 1–800–800–2726. Furnish the Serial No. and Catalog
No. from the transfer switch nameplate.
381333-415 B 9
Page 10
Installation Manual Bypassing & Isolating
BYPASSING & ISOLATING
BYPASSING THE ATS*
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 8, 9 and
10.
Indicator shows:
green
ATS is not
OPEN when the
bypassed.
You can only bypass to the same source that the
Transfer Switch is connected. Solenoid interlock
prevents incorrect operation.
1 .Observe which Transfer Switch Connected To light
is on (Normal or Emergency) on the door. This is
the position of the automatic transfer switch.
2.Bypass to the same source as connected to transfer
switch as follows (select Normal or Emergency).
Indicator shows:
yellow
when ATS is bypassed to Emergency
or
yellow
ATS is bypassed to Normal Source.
EMERGENCY CLOSED
NORMAL CLOSED when
To Bypass Normal push in handle
all the way & turn it clockwise.*
Figure 8. Bypass Handle and position indicators.
To Bypass Normal Source*
(Load connected to Normal Source)
The Transfer Switch Connected To Normal light is
on and Transfer Switch Connected To Emergency
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.
Push in
Bypass
Handle
&
turn it
clockwise.
Bypass Switch
E
L
To Bypass Emergency pull out han
dle all the way & turn it clockwise.*
To Bypass Emergency Source*
(Load connected to Emergency Source)
The Transfer Switch Connected To Emergency light
is on and Transfer Switch Connected To Normal
light is off.
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.
Pull out
Bypass
Handle
&
turn it
clockwise.
Bypass Switch
E
L
N
ATS
Figure 9. Bypass to Normal.
The automatic transfer switch can now be put in the TEST or OPEN position. See ISOLATING on page 11.
* NOTE: When Accessory 66A (reversed Normal & Emergency connections) is specified,
the handle push–pull operation is reversed. Follow instructions on the door.
10 381333-415 B
Figure 10. Bypass to Emergency.
ATS
N
Page 11
Bypassing & Isolating Installation Manual
ISOLATING THE ATS
Isolating is required before any service work can be
performed on the automatic transfer switch (ATS).
Refer to Figures 11,12, 13, 14 and 15..
1. Bypass the closed automatic transfer switch
contacts. See BYPASSING on page 10.
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 8).
Bypass Switch
Turn crank
counter
clockwise
until
window
shows
TEST.
E
L
position. The transfer switch can also be
removed for easier maintenance operations.
position
CONN
TEST
ISOLATE
counterclockwise – draws out transfer switch
window
unfold
crank
Figure 13. Isolation Handle.
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.
Figure 11.
Figure 3–4.
CONNECTED to
CONNECTED to
TEST position.
TEST position.
Automatic Transfer Switch
N
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
counter
clockwise
until
L
window
shows
ISOLATE.
Figure 12
Figure 3–5.
TEST to
TEST to
ISOLATE
position.
ISOLATE
position.
Automatic Transfer Switch
N
4. Open the lower enclosure doors(s). Pull out the
side rail carriage. On 4000 A extend two support
legs. See Figures 14 and 15. Then roll out the
transfer switch. It can be safely inspected in this
Figure 14. 600–3000 A transfer switch
isolated and pulled out for inspection.
See page 8 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.
Continued on next page
381333-415 B 11
Page 12
Installation Manual Bypassing & Isolating
grasp two handles
locking pin
with clevis pin
rail support
left support leg
adjust length to touch floor
4000 A transfer switch draw–out procedure
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).
carriage
Figure 15. 4000 A transfer switch isolated and pulled out for inspection.
locking pin
with clevis pin
right support leg
adjust length to touch floor
For the 4000 A transfer switch, to avoid personal
injury and equipment damage, two support legs
must be extended as shown in Figure 15.
Substantial initial force is required to pull out the
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
transfer switch (there are detents on rail).
12 381333-415 B
Page 13
Bypassing & Isolating Installation Manual
to
y By
(
g
RETURN TO SERVICE
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 14 through 18.
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 14 and 15.
Then close enclosure door(s).
Close the enclosure door to prevent personal
injury in case of electrical system fault.
Align the position indicator. Do not leave
the handle in an intermediate position.
position
CONN
TEST
ISOLATE
window
Solenoid interlock prevents closing the isolation
contacts until the ATS is in the same position as
the Bypass Switch.
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
Operate to NORMAL Operate
Turn Transfer Control
switch to Retransfer
Dela
pass.
Connected To Normal
li
ht should come on.
Turn Transfer Control
switch to Transfer Test
hold 15 seconds).*
Connected To Emergency
light should comes on.
EMERGENCY
* If Feature 2B time delay is used, there will be a
delay before transfer to Emergency.
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 16. 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 8).
Bypass Switch
E
Turn crank
clockwise
L
until
window
shows
TEST.
N
ATS
Figure 17. ISOLATE to TEST position.
Do not close the isolation contacts unless the
Transfer Switch (ATS) and Bypass Switch are in
the same position!
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
Turn crank
clockwise
until window
shows
CONN
(connected).
Figure 18. TEST to CONNECTED position.
ATS
Continued on next page
E
L
N
381333-415 B 13
Page 14
Installation Manual Bypassing & Isolating
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 13. See Figures
19, 20 and 21.
Indicator shows:
green
ATS is not
To un–Bypass Normal push in handle
all the way & turn it counterclockwise.*
OPEN when the
bypassed.
Figure 19. Bypass Handle and position indicators.
You can only bypass to the same source that the
ATS is connected. Solenoid interlock prevents
incorrect operation.
1. Observe which Bypass Switch Position indicator is
yellow (NORMAL or EMERGENCY) at the Bypass
Switch Handle. This indicates the source connected
to the load.
2. Un–Bypass to same source as the Bypass Switch
Position as follows (select Normal or Emergency).
Indicator shows:
yellow
when ATS is bypassed to Emergency
or
yellow
bypassed to Normal Source.
To un
handle all the way & turn it
counterclockwise.*
EMERGENCY CLOSED
NORMAL when ATS is
–
Bypass Emergency pull out
To Un–Bypass Normal Source*
(Load connected to Normal Source)
The Transfer Switch Connected To Normal light is
on and Transfer Switch Connected To Emergency
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.
Push in
Bypass
Handle
&
turn it
counter
clockwise.
Bypass Switch
E
L
N
To Un–Bypass Emergency Source*
(Load connected to Emergency Source)
The Transfer Switch Connected To Emergency light
is on and Transfer Switch Connected To Normal
light is 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.
Pull out
Bypass
Handle
&
turn it
counter
clockwise.
Bypass Switch
E
L
N
ATS
Figure 20. Un–Bypass Normal.
The Automatic Closed–Transition Transfer & Bypass–Isolation Switch should be left in this position.
Figure 21. Un–Bypass Emergency.
ATS
When Accessory 40*B (reversed Normal & Emergency connections) is specified, the handle push–pull
operation is reversed. Follow instructions on the door.
14 381333-415 B
Page 15
Installation Manual Index
A
Alarm Reset pushbutton, 7, 9
ASCO Power Services Inc.
customercare@ascopower.com
800–800–2726(ASCO)
auxiliary circuits, 5
B
bus connections, 5
bypassing the ATS, 10
harness, 5
HELP
customercare@ascopower.com
800–800–2726(ASCO)