Regal Thomson Power Systems TS 880 Service manual

PM178
Rev 0
23/02/20
TS 880
AUTOMATIC TRANSFER SWITCH
WITH TSC 7320 CONTROLLER
INSTALLATION, OPERATING & SERVICE
MANUAL
4916 -275th Street, Langley, BC, Canada V4W 0A3 ·Telephone [phone]
Email: [email protected] · www.thomsonps.com

TS 880 Transfer Switch
PM178 REV 0 23/02/20 Thomson Power Systems
1. PRODUCT REVISION HISTORY 4
2. EQUIPMENT STORAGE 4
2.1. ENVIRONMENTAL CONDITIONS 4
3. NOTES TO INSTALLER 5
3.1. UPSTREAM CIRCUIT PROTECTIVE DEVICES/ELECTRICAL CONNECTIONS 5
3.2. TRANSFER SWITCHES WITH INTEGRAL OVER CURRENT PROTECTION 5
3.3. TRANSFER SWITCHES WITH MULTI-TAP VOLTAGE CAPABILITY 6
3.4. REMOTE START CONTACT FIELD WIRING 6
3.5. DIELECTRIC TESTING 7
3.6. MOUNTING OF ENCLOSED TRANSFER SWITCHES 7
3.7. PRODUCT MODEL CODE 11
4. AUTOMATIC SEQUENCE OF OPERATION 12
4.1. STANDARD ATS - OPEN TRANSITION 12
4.2. STANDARD ATS - CLOSED TRANSITION 13
4.3. SERVICE ENTRANCE ATS 17
4.4. TEST MODES 20
5. OVER CURRENT PROTECTION 21
5.1. STANDARD TS 880 AUTOMATIC TRANSFER SWITCH 21
5.2. OPTIONAL TS 880 ATS WITH INTEGRAL OVER CURRENT PROTECTION 21
6. SERVICING TRANSFER SWITCH MECHANISMS 22
6.1. SERVICING INSULATED CASE TYPE TRANSFER MECHANISMS 22
7. TRANSFER SWITCH MECHANISM OPERATION 24
7.1. GENERAL DESCRIPTION 24
8. MANUAL OPERATION 25
9. FRONT VIEW (TYPICAL) INSULATED CASE TYPE TRANSFER MECHANISM 33
10. CABLE TERMINAL INFORMATION 35
11. REQUIREMENTS FOR UPSTREAM CIRCUIT PROTECTIVE DEVICES 36

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11.1. WITHSTAND CURRENT RATINGS (STANDARD 3 CYCLE MODELS) 36
11.2. INTERRUPTING CAPACITY CURRENT RATINGS (STANDARD 3 CYCLE MODELS)
37
11.3. WITHSTAND CURRENT RATINGS (30 CYCLE MODELS) 38
11.4. INTERRUPTING CAPACITY CURRENT RATINGS (30 CYCLE MODELS) 39
12. GROUND FAULT SITE TEST REQUIREMENTS 40
12.1. PERFORMANCE TEST 40
13. POWER SWITCHING DEVICE TROUBLESHOOTING 46
14. POWER SWITCHING DEVICE DETAILS 48
15. POWER SWITCHING DEVICE ELECTRICAL DIAGRAMS 52
16. REPLACEMENT PARTS 60
17. PRODUCT RETURN POLICY 61
18. NOTES 62
19. PERFORMANCE TEST FORM 63
APPENDIX A –TYPICAL TS 880 ATS COMMISSIONING PROCEDURE
APPENDIX B –TS 880 SYSTEM VOLTAGE CHANGE PROCEDURE
APPENDIX C –SEISMIC CERTIFICATE

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1. PRODUCT REVISION HISTORY
The following information provides an historical summary of changes made to this product since the
original release.
Operating & Service Manual Version
PM178 Rev 0 23/02/20
Original release
Contact Thomson Power Systems, to obtain applicable instruction manuals or if in doubt about any
matter relating to installation, operation or maintenance. Soft copy of the most current version is
available at www.thomsonps.com.
NOTE: All information contained in this manual is for reference only and is subject to change without
notice.
Related Product Instruction Manuals
•TSC 7320 Transfer Switch Controller, PM180
Contact Thomson Power Systems, to obtain these instruction manuals. Soft copy of the most
current versions of these manuals are available at www.thomsonps.com.
2. EQUIPMENT STORAGE
The following procedures are required for correct storage of the transfer switch prior to installation.
2.1. ENVIRONMENTAL CONDITIONS
CAUTION
Failure to store and operate equipment under the specified environmental conditions
may cause equipment damage and void warranty.
2.1.1. EQUIPMENT STORAGE
The transfer switch shall be stored in an environment with a temperature range not
exceeding -4° to +158° Fahrenheit (-20° to +70° Celsius) and a humidity range not
exceeding 5%-95% non-condensing. Before storing, unpack sufficiently to check for
concealed damage. If concealed damage is found, notify the ATS supplier and the
Carrier immediately. Repack with the original or equivalent packing materials. Protect
from physical damage. Do not stack. Store indoors in a clean, dry, well ventilated area
free of corrosive agents including fumes, salt and concrete/cement dust. Apply heat as
necessary to prevent condensation.

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2.1.2. EQUIPMENT OPERATING
The transfer switch shall be operated in an environment with a temperature range not
exceeding +5° to +122° Fahrenheit (-15° to +50° Celsius) and a humidity range not
exceeding 5%-95% non-condensing.
3. NOTES TO INSTALLER
DANGER
Arc Flash and Shock Hazard. Will cause severe injury or death.
Do not open equipment until ALL power sources are disconnected
This equipment must be installed and serviced only by qualified electrical personnel
utilizing safe work practices and appropriate Personal Protective Equipment (PPE).
Failure to do so may cause personal injury or death
3.1. UPSTREAM CIRCUIT PROTECTIVE DEVICES/ELECTRICAL CONNECTIONS
To ensure satisfactory installation of this equipment be sure to observe Cable Terminal
Information regarding power cable connection tightness and Requirements for Upstream
Circuit Protective Devices located in this manual.
All mechanical and electrical connections must be checked for tightness prior to placing this
equipment in service to ensure proper operation and to validate applicable warranty coverage.
3.2. TRANSFER SWITCHES WITH INTEGRAL OVER CURRENT PROTECTION
For models of transfer switch with integral over current protection, the over current protection
must be set prior to operation. The equipment will be shipped from the factory with a long-time
current setting of 100%, of the equipment rating, and maximum short-time/instantaneous
current and time delay settings.
WARNING
Do Not Energize this equipment until device settings have been
verified to ensure proper system protection & coordination. Failure to
do so may result in equipment failure.
Refer to SECTION 4.3.2 of this manual for additional information on operation of the Transfer
switch following an over current trip condition.

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Refer to information supplied with the transfer switch documentation package for adjustment
procedures on the power switching units over current protection trip unit. Contact the factory if
any additional information is required.
3.3. TRANSFER SWITCHES WITH MULTI-TAP VOLTAGE CAPABILITY
If the transfer switch has programmable multi-tap voltage capability (refer to engineered
drawings), confirm the transfer switch has been configured for the correct system voltage prior
to installation.
WARNING
Failure to confirm and match transfer switch voltage with the system
voltage could cause serious equipment damage.
The voltage selections and connections are shown on the engineered drawings attached to
each transfer switch. The factory default settings will be indicated on the calibration label
attached on the inside of the enclosure door (supplied loose on open style models). A blank
label is included to record the applicable settings if the configuration is changed from the
factory default settings.
To change the transfer switch voltage, refer to Instructions To Change System Voltage On
TS 880 Series Transfer Switches With TSC 7320 Controller, attached as Appendix B. Contact
Thomson Power Systems for further information as may be required.
3.4. REMOTE START CONTACT FIELD WIRING
As a minimum, the remote engine start control field wiring shall conform to the local regulatory
authority on electrical installations. Field wiring of a remote start contact from a transfer switch
to a control panel should conform to the following guidelines to avoid possible controller
malfunction and/or damage.
3.5.1. Minimum #14 AWG (2.5mm2) wire size shall be used for distances up to 100ft
(30m)1). For distances exceeding 100 ft. (30m) consult Thomson Power Systems
3.5.2. Remote start contact wires should be run in a separate conduit.
3.5.3. Avoid wiring near AC power cables to prevent pick-up of induced voltages.
3.5.4. An interposing relay may be required if field-wiring distance is excessively long
(i.e. greater than 100 feet (30m)) and/or if a remote contact has a resistance of greater
than 5.0 ohms.
3.5.5. The remote start contact must be voltage free (i.e. dry contact). The use of a
Powered contact will damage the transfer controller.

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3.5. DIELECTRIC TESTING
Do not perform any high voltage dielectric testing on the transfer switch with the TSC 7320
controller connected into the circuit as serious damage will occur to the controller. All AC
and DC control fuses and control circuit isolation plugs connected to the TSC 7320 must be
removed if high voltage dielectric testing is performed on the transfer switch.
3.6. MOUNTING OF ENCLOSED TRANSFER SWITCHES
Model TS880 Automatic Transfer Switches and Automatic Transfer and Bypass Isolation
Switches in Standard enclosures are seismic certified under AC156 building code for non-
structural components.
Standard enclosures are all transfer switch enclosures Thomson Power Systems offers in
NEMA 1, NEMA 2, NEMA 3R and NEMA 4X for the above listed product. If a customer
requests a custom enclosure, it would not be covered under the generic certificate; if
certification were a requirement then consult factory before ordering.
The Automatic Transfer Switches are qualified to the highest known level in North America;
based on site class D. Specifically, this is a spectral acceleration of 200%.
The transfer switch must be installed per the anchoring details provided for seismic
qualification. The equipment can be mounted in alternate means and still qualify if a qualified
Civil Engineer designs the alternate method of anchoring.

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Anchoring Notes:
1. Anchoring must be designed according to IBC 2012 or latest version.
2. The anchoring details shown are recommended according to the seismic
certification; design Engineer may use alternate anchors within the scope of IBC.
3. Wall anchors in concrete; use a typical concrete anchor as necessary.
4. Expansion anchors as shown. To be installed according to manufacturer's
recommendation.

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GENERAL DESCRIPTION
Thomson Power Systems TS 880 series of Automatic Transfer Switches employ two mechanically
interlocked enclosed contact power switching units and a microprocessor based controller to
automatically transfer system load to a generator supply in the event of a utility supply failure. System
load is then automatically re-transferred back to the utility supply following restoration of the utility
power source to within normal operating limits.
The standard TS 880 series Automatic Transfer Switch is rated for 100% system load and requires
upstream over current protection. The TS 880 Automatic Transfer Switch may be supplied with
optional integral over current protection within the enclosed contact power switching units for
applications such as Service Entrance Rated equipment. Refer to SECTION 5 of this manual for
detailed information on over current protection.
The TS 880 series transfer switches employs a TSC 7320 Microprocessor Based controller which
provides all necessary control functions for fully automatic operation. The controller is equipped with
2.3” back-lit LCD display which provides operating status and controls.
For further information on the TSC 7320 Transfer Controller, refer to instruction manual PM180.

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800A - 4000A rated insulated case power switching devices used for the utility and generator sources
are operated by internal drive motor operators. The transfer switch mechanism utilizes the power from
the source to which the electrical load is being transferred. The mechanism provides a positive
mechanical interlock to prevent both power switching units from being closed at the same time, which
allows an interrupted open transition “break-before-make” transfer sequence. For transfer switches
supplied with Closed Transition transfer option, the mechanical interlock is removed thereby allowing
a “make-before break” transfer sequence when both sources of power are available. The TSC 7320
transfer controller provides a standard neutral position delay timer for open transition transfer
sequences to allow adequate voltage decay during transfer operation to prevent out of phase
transfers.
NOTE
For the purpose of this manual, the following standard nomenclature
is utilized:
Utility: to indicate the source of primary power
Generator: to indicate the source of standby power
Power Switching Device: to indicate the Automatic Transfer Switch
power switching device

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3.7. PRODUCT MODEL CODE
The type of TS 880 series transfer switch supplied is identified by way of a 21-digit product
code which appears on the equipment rating plate, or Model, on the door of the transfer switch,
and on the transfer switch drawings. The model code structure and definitions are as follows:
1-3. SERIES
TS - TRANSFER SWITCH
4 & 5. MODEL
88 - 880 SWITCH
6. POLES
3 –3 - POLES
4 –4 - POLES
7. CONFIGURATION TYPE
A –ATS
B - BYPASS/ISOLATION ATS
X - SPECIAL
8 - 11. AMPERAGE
800
1000
1200
1600
2000
2500
3000
3200
4000
12. APPLICATION
A - STANDARD
B - SERVICE ENTRANCE
C - DUAL UTILITY CONTROL
D - DUAL STANDBY GEN (Slave ATS)
E - 30 CYCLE STANDARD
F - 30 CYCLE SERVICE ENTRANCE
G - 30 CYCLE DUAL UTILITY (DU)
H - DUAL PRIME GEN CONTROL
I - 30 CYCLE DUAL STANDBY GEN (DSG)
J - 30 CYCLE DUAL PRIME GEN (DPG)
X –SPECIAL
13. OPERATION TYPE
1 - OPEN TRANSITION
2 - MANUAL ELEC. OP.
3 - CLOSED TRANSITION (MOMENTARY)
4 - CLOSED TRANSITION (SOFT LOAD)
X –SPECIAL
14. SAFETY STANDARD
A - UL 1008 (Service Entrance)
C - UL 1008 / CSA 178
X - NOT APPLICABLE
15. VOLTAGE
3Ø 4 WIRE (GROUNDED NEUTRAL)
E - 120/208 1
F - 127/220
G - 120/240 1(DELTA)
H - 220/380 2
S - 230/4002
J - 240/416
K - 254/440
M - 277/480 1
N - 347/600 1
3Ø 3 WIRE
P - 208
Q - 220
R - 240
U - 416
V - 480
W - 600
X - SPECIAL
16. CONTROLLER
5 - TSC 900 c/w GHC GRAPHIC DISPLAY
6 - TSC 7320 c/w LCD DISPLAY
7 - NONE (MANUAL)
17. ENCLOSURE TYPE
A - NEMA1, ASA #61 GRAY
B - NEMA2, ASA #61 GRAY
C - NEMA12, ASA #61 GRAY
D - NEMA3R SD, ASA #61 GRAY
E - NEMA3R DD, ASA #61 GRAY
F - NEMA3RX / 4X DD
(304 STAINLESS STEEL)
G - NONE (OPEN STYLE)
H - NEMA 4X SD
(304 STAINLESS STEEL)
K - NEMA 4X SD
(316 STAINLESS STEEL)
L - NEMA3RX / 4X DD
(316 STAINLESS STEEL)
X - SPECIAL
18. UTILITY SWITCHING DEVICE
Q - INSULATED CASE, FIX MOUNT SWITCH
R - INSULATED CASE, FIX-MOUNT SWITCH
C/W ELECTRONIC TRIP
T - INSULATED CASE, FIX-MOUNT SWITCH
C/W ELECTRONIC & GF TRIP
U - INSULATED CASE DRAW-OUT SWITCH
V - INSULATED CASE DRAW-OUT SWITCH
C/W ELECTRONIC TRIP
W - INSULATED CASE, DRAW-OUT SWITCH
C/W ELECTRONIC & GF TRIP
X - SPECIAL
19. GENERATOR SWITCHING DEVICE
Q - INSULATED CASE, FIX MOUNT SWITCH
R - INSULATED CASE, FIX-MOUNT SWITCH
C/W ELECTRONIC TRIP
T - INSULATED CASE, FIX-MOUNT SWITCH
C/W ELECTRONIC & GF TRIP
U - INSULATED CASE DRAW-OUT SWITCH
V - INSULATED CASE DRAW-OUT SWITCH
C/W ELECTRONIC TRIP
W - INSULATED CASE, DRAW-OUT SWITCH
C/W ELECTRONIC & GF TRIP
X - SPECIAL
20. POWER CONNECTIONS
A –STANDARD
C - ATS CONNECTION PLATE 800A
D - ATS CONNECTION PLATE 1000/1200A
F - ATS CONNECTION PLATE 800A - U & G
G - ATS CONNECTION PLATE 1000/1200A - U & G
H - ATS CONNECTION PLATE 1600A
I - ATS CONNECTION PLATE 2000A
J - ATS CONNECTION PLATE 2500A
K - ATS CONNECTION PLATE 3000/3200A
L - ATS CONNECTION PLATE 4000A
X –SPECIAL
21. ATS CONNECTION CONFIGURATION 6
A –STANDARD
E - ALTERNATE E
F - ALTERNATE F
G - ALTERNATE G
X –SPECIAL
NOTES:
1MULTI-VOLTAGE CAPABLE
2FOR 50 Hz APPLICATION
6FOR BYPASS SWITCH APPLICATIONS
REFER TO FACTORY

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TYPICAL COMMISSIONING PROCEDURES
CAUTION
Commissioning procedures must be performed by
qualified personnel only. Ensure the Automatic Transfer
Switch (ATS) ATS Power Chassis & Voltage Sensing
Isolation Plugs PL12 & PL15 are disconnected prior to
energizing the supply sources. Manually place the
transfer switch mechanism in the neutral position prior to
applying power. Failure to do so may result in equipment
failure or personal injury.
NOTE: The Typical Automatic Transfer Switch Commissioning Procedures Model Series TS
880, attached as Appendix A, is provided for general information only pertaining to typical site
installations and applications. Contact Thomson Power Systems for further information as
may be required.
4. AUTOMATIC SEQUENCE OF OPERATION
4.1. STANDARD ATS - OPEN TRANSITION
When utility supply voltage drops below a preset nominal value (adjustable from 50% to 95%
of nominal) on any phase, an engine start delay circuit is initiated and the transfer to utility
supply signal will be removed (i.e. contact opening). Following expiry of the engine start delay
period (adjustable from 0 to 30 sec.) an engine start signal (contact closure) will be given.
Once the engine starts, the transfer switch controller will monitor the generator voltage and
frequency. Once the generator voltage and frequency rises above preset values (adjustable
from 70% to 99% of nominal), the engine warmup timer will be initiated. Once the warmup
timer expires (adjustable from 0 to 60 min.), the transfer to Generator Supply signal (contact
closure) will be given to the transfer switch mechanism. The load will then transfer from the
utility supply to the generator supply via the motor operated mechanism.
NOTE: A neutral delay timer circuit will delay the transfer sequence in the neutral position (i.e.
both power switching devices open) until the selected time expires (adjustable from 0 to 120
sec.).
The generator will continue to supply the load until the utility supply has returned. The
retransfer sequence is completed as follows: when the utility supply voltage is restored to
above the preset values (adjustable from 70% to 99% of nominal) on all phases, a utility return
delay circuit will be initiated. Following expiry of the Utility Return Timer (adjustable from 0 to
30 min.), the Transfer to Generator Supply signal will be removed (contact opening), and then
the Transfer to Utility Supply signal (contact closure) will be given to the transfer switch

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mechanism. The load will then retransfer the load from the generator supply back to the utility
supply.
NOTE: A neutral delay timer circuit will delay the transfer sequence in the neutral position (i.e.
both power switching devices open) until the neutral delay time period expires.
An engine cooldown timer circuit will beinitiated once the load istransferredfrom the generator
supply. Following expiry of the cooldown delay period (adjustable from 0 to 60 minutes), the
engine start signal will be removed (contact opening) to initiate stopping of the generator set.
4.2. STANDARD ATS - CLOSED TRANSITION
NOTE: This section applies only to Closed Transition configured transfer switches.
For transfer switches equipped with the Closed Transition transfer option, the ATS is
configured to operate as follows:
Under normal closed transition operating conditions, the transfer switch operates automatically
during a failure and restoration of utility power and does not require operator intervention.
When utility supply voltage drops below a preset nominal value (50 –95% of rated adjustable)
on any phase, an engine start delay circuit will be initiated and the transfer to utility supply
signal will be removed (i.e. contact opening). Following expiry of the engine start delay period
(0 - 30 sec. adjustable) an engine start signal (contact closure) will be given.
Once the engine starts, the transfer switch controller will monitor the generators voltage and
frequency levels. Once the generator voltage and frequency rises above preset values (50 –
95% nominal adjustable) a warmup time delay will be initiated. Once the warmup timer (0-60
Min adjustable) expires, the transfer to generator supply signal (contact closure) will be given
to the transfer switch mechanism. The load will then transfer from the utility supply (i.e.
opening the utility powerswitching device) to thegenerator supply(closing the generator power
switching device) via motor driven mechanism to complete a break-before-make open
transition transfer sequence.
The generator will continue to supply the load until the utility supply has returned and the
retransfer sequence is completed as follows: When the utility supply voltage is restored to
above 90% of nominal voltage on all phases, a re-transfer sequence will be initiated once the
Utility Return timer expires. The utility will close its power switching device when it is in
synchronism with the generator supply utilizing the TSC 7320 in-phase monitor. The generator
power switching device will immediately trip open approximately 50-100 milliseconds after the
utility power switching device closes to complete the make-before-break re-transfer sequence.
An engine cooldown timer circuit will be initiated once the load istransferredfrom the generator
supply. Following expiry of the cooldown delay period (0 - 60 min. adjustable) the engine start
signal will be removed (contact opening) to initiate stopping of the generator set.

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Closed Transition Operation Sequence Diagram
(Normal Power Failure & Return Sequence)
The following operating sequences and time delays are associated with closed
transition type transfer switches which momentarily parallel two sources of supply for
less than 100 milliseconds. For closed transition type transfer switches, which utilize
extended parallel operation for soft-loading operating sequences, refer to separate
instruction manual.
1. Transfer Control Switch (Open/Closed Transition): A two position selector switch is
provided on the front of the transfer switch for operator section of desired operation.
The two positions are as follows:
▪OPEN TRANSITION: The transfer switch will operate in a break-
before-make open transition sequence during load transfers. A
programmed neutral delay period will occur during the transfer
sequence to ensure voltage decays on the load bus before load is
re-applied. The two sources will not be paralleled at any time during
operation in this mode.
▪CLOSED TRANSITION: When both sources of supply are available,
the transfer switch will operate in a make-before-break closed
transition sequence during load transfers.

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NOTE: If only one source of supply is available during an initiated
transfer sequence, the control system will automatically revert to an
open transition transfer sequence.
2. Synchronizing Protection: To ensure both sources are in synchronism prior to
initiating a closed transition transfer sequence, a TSC 7320 in-phase monitor is
used. The controller has a Sync page to allow monitoring of phase and voltage of
the 2 sources. The built-in sync check relay will block a closed transition transfer
sequence until both sources phase angle and voltages are within programmed
limits. The synch check relay settings are factory programmed to the following:
Factory Settings:
Frequency Delta:
±0.5Hz
Voltage Delta:
30V PhN
Phase Angle Delta:
10°
NOTE: The standard closed transition transfer switch does not contain an
automatic synchronizer to control the generators frequency or voltage to bring it
within limits of the sync check relay. For correct closed transition transfer operation,
the system requires the generators frequency to be set within 0.25% of nominal
frequency and the generators voltage to be set within 0.5% of nominal voltage.
3. Closed Transition Time Period: The time period in which both sources of supply are
paralleled together during the closed transition transfer sequence is 50-100
milliseconds (maximum). The time period is inherently controlled by operation of
auxiliary contacts from the power switching devices (i.e. when one switching
devices closes, its aux contact closes to initiate tripping of the opposite switching
device).

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4. Closed Transition Failure Mode Operation: The TSC 7320 continually monitors the
closed transition operation time period. The TSC 7320 is factory set for 100
milliseconds that allows normal closed transition operation (i.e. both power
switching devices remain closed for less than 100 milliseconds). The alarm circuit
is not activated under normal operation. Should the closedtransition operation time
exceed 100 milliseconds (i.e. both power switching devices remain closed for
longer than the normal closed transition time period plus the setting of TSC 7320
timer, the following sequence of events will occur:
•TSC 7320 time delay period will expire and will activate auxiliary trip relay.
•If the transfer switch was transferring power from the generator source to the
utility source and the generator switching device failed to open, an auxiliary trip
relay will trip open the utility power switching device to immediately separate
the two power sources. If the transfer switch was transferring power from the
utility source to the generator source and the utility switching device failed to
open, an auxiliary trip relay will trip open the generator power switching device
to immediately separate the two power sources.
NOTE: The maximum time period both sources will remain paralleled under
this failure mode is 200 milliseconds.
•The original source (i.e. prior to the transfer sequence) will remain on load,
separated from the other source. TSC 7320 controller will indicate a failure
condition which must be manually reset before the transfer switch will re-
attempt subsequent transfers. For further information on the TSC 7320 features
and operation, refer to the separate product instruction manual.
NOTE: Should the TSC7320 fail to separate the 2 sources under 350msec, a
secondary paralleling timer relay will issue a trip signal to both power switching
devices. The maximum time period both sources will remain paralleled under
this failure mode is 500 milliseconds.
Two alarm contacts are provided for the Closed Transition Failure Mode (i.e.
one for a failed generator power switching device and one for the utility power
switching device. The contacts are for customer use to remotely trip open
upstream devices should an abnormal condition persist.
5. Transfer Fail Alarm (Switching Device Fail to Close): The TSC 7320 provides a
timer detect and alarm abnormal operating conditions. Should a power switching
device fail to close for any reason within a 5-minute time period, an alarm light and
alarm relay contact will be activated. For further information on the TSC 7320
features and operation, refer to the separate product instruction manual.

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4.3. SERVICE ENTRANCE ATS
NOTE: This applies only to service entrance transfer switches
4.3.1. NORMAL OPERATION
Under normal conditions, the loadis energizedfrom the utility supply through the closed
utility transfer power switching device. If the utility power fails, the generator will start
and the load will be re-energized via the closed generator transfer power switching
device.
In the normal operating mode, the Service Disconnect switch shall be in the Energized
position.
4.3.2. OVER CURRENT TRIP
Should the utility power switching device trip open due to an over current condition,
TSC 7320 transfer controller will initiate an engine start signal and will permit transfer
of the load to the generator supply. The utility source will be locked out and the load
will remain on the generator supply until the TSC 7320 alarm signal is manually reset.
Should the generator power switching devicetrip open dueto an over current condition,
TSC 7320 transfer controller will initiate transfer of the load to the utility supply. The
generator source will be locked out and the load will remain on the utility supply until
the TSC 7320 alarm signal is manually reset.
4.3.3. SERVICE DISCONNECT PROCEDURE
To perform a service disconnect (i.e. to disconnect the utility and generator supplies),
the following procedure is required:
a. Move the Service Disconnect control switch located on the door of the
transfer switch to the "Transfer to Neutral Position” position.
b. Once the ATS has transferred to the neutral position, move the Service
Disconnect control switch to the Disconnected position.
c. Verify that the Service Disconnected pilot light is illuminated. If the Light is
illuminated, the service has been successfully disconnected and it is safe to
perform any maintenance procedures as required. In this condition, the
transfer switch is in the neutral position, with both utility and generator
transfer power switching devices open. The transfer switch will remain in
this condition, regardless of condition of the utility and generator supplies.
NOTE:If the Service Disconnect Light is not illuminated, additional
procedures are required (refer to the following procedure #4.3.4).
d. Attach safety lockout padlock to the Service Disconnect control switch to
prevent unauthorized change in operating condition and verify transfer

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switch door is locked closed. If the door is not locked, turn and remove door
key.
WARNING
Close and lock the transfer switch enclosure door before
connecting power sources.
e. To re-energize the load, remove the padlock(s) from the service disconnect
control switch, and move the switch to the Energized position. The transfer
switch will immediately return to the utility or generator supply if within
normal operating limits.
4.3.4. ADDITIONALSERVICE DISCONECT PROCEDURES
If the Service Disconnected pilot light is not illuminated, the service will not have been
successfully disconnected and therefore it is not safe to perform any maintenance until
the following additional procedures are performed:
DANGER
Arc Flash and Shock Hazard. Will cause severe injury or death.
Do not open equipment until ALL power sources are disconnected
This equipment must be installed and serviced only by qualified electrical
personnel utilizing safe work practices and appropriate Personal Protective
Equipment (PPE). Failure to do so may cause personal injury or death.
1. Visually inspect the actual position of the transfer switch power switching
devices. If both power switching devices indicate they are open, the transfer
switch is clearly in the Neutral Position, the service has been successfully
disconnected. Proceed to Step. 4.
If either power switching device is not in the Open position, or the load bus is
energized, further procedures are required.
NOTE: If the power switching devices are bothOpen, the ServiceDisconnected
pilot light may not have illuminated due to the following reasons:
a) Utility and generator supply voltages are not present (the pilot light
requires AC supply voltage to be present).
b) The pilot light may be burnt out. The bulb should be immediately
replaced with a 6Vdc rated LED bulb.

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PM178 REV 0 23/02/20 19 Thomson Power Systems
c) Failure of one or more of the sensing/logic contacts. A qualified service
technician is required to trouble shoot this specific condition. Switch the
utility control circuit isolation switch to the de-energized position to
remove utility control power. To isolate the ATS Power Chassis &
Voltage Sensing circuits, remove the isolation plugs PL12 and PL15.
NOTE: The AC power conductors will remain energized. Once all the
control and voltage sensing circuits are de-energized and isolated the
Service Disconnected pilot light will not illuminate due to loss of control
power.
NOTE: To return the transfer switch back to normal operation, the utility
control circuit disconnect switch and ATS Power Chassis & Voltage
Sensing Isolation Plugs (PL12 & PL 15) must be switched on and
reconnected for correct operation.
2. If the position of both power switching units are not in the Open position, the
power switching units must be manually operated as follows. To operate
manually, push the power switching units Open pushbutton. The unit should
then open. Repeat for the other power switching unit.
3. Close all transfer switch doors securely using a suitable tool. Lock the door in
the closed position and remove the key.
WARNING
Failure to move the mechanism to the Neutral Position may
result in serious personal injury or death due to electrical
shock.
4. Attach a safety lockout padlock to the service disconnect control switch to
prevent unauthorized change in operating condition and verify transfer switch
door is locked closed.
5. To reenergize the load, remove the padlock(s) from the service disconnect
control switch, and move the switch to the “Energized” position. The transfer
switch will immediately return to the utility or generator supply if within normal
operating limits.

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PM178 REV 0 23/02/20 20 Thomson Power Systems
4.4. TEST MODES
The transfer switch may be tested utilizing the TSC 7320 front panel buttons or remote power
fail test input. A simulated utility power failure condition will be activated when the test mode
is selected. The transfer switch will operate as per a normal utility power fail condition.
The transfer switch will remain on generator supply until the test mode is terminated. It will
then immediately transfer back to the utility supply and then continue to operate the generator
set for its cooldown period then stop.
NOTE: The transfer switch will automatically return tothe utility supply(if within nominal limits)
if the generator set fails while in the test mode.
4.4.1. ON LOAD TEST
To initiate an ATS On Load Test, press the test button on the TSC 7320 controller to
enter test mode.
Next, press the gen start button (green), and the controller will start the generator and
once it reaches the nominal voltage and frequency, the switch will be transferred to the
generator and take over the load.
To stop the on-load test and return to normal, press the auto button, and the controller
will start a utility return delay timer, and transfer back to the utility when the timer
expires. The generator will continue to run until the cooling expires, and then it will turn
off the generator.
NOTE : Pushing the red stop button will initiate a return to Utility request followed by
an engine stop. If the utility is available, the ATS will transfer to utility and stop the
engine ignoring any countdown timers. If the Utility is not available, the controller will
turn off the generator, and generate a Mains Fail to Close Alarm.
4.4.2. OFF LOAD TEST
To initiate an ATS off load test, press the manual button on the TSC 7320 controller to
enter manual mode.
Next, press the gen start button (green), and the controller will start the generator, but
the switch will NOT transfer to generator, even if the source is healthy.
To stop the off-load test and return to normal, press the STOP button, and the
controller will turn off the generator. If the Auto mode button is pushed, the controller
will start a countdown timer and then turn off the generator.
.