THOMSON TS 840 User manual

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TS 840
AUTOMATIC TRANSFER SWITCHES
INSTALLATION, OPERATING &
SERVICE MANUAL
PM057 Rev 8 10/01/25

TS 840 TRANSFER SWITCH
PM057 REV 8 10/01/25 Thomson Technology
TABLE OF CONTENTS
1. PRODUCT REVISION HISTORY 1
2. EQUIPMENT STORAGE 1
2.1. ENVIRONMENTAL CONDITIONS 1
3. NOTES TO INSTALLER 2
3.1. UPSTREAM CIRCUIT PROTECTIVE DEVICES/ELECTRICAL CONNECTIONS 2
3.2. TRANSFER SWITCHES WITH INTEGRAL OVER CURRENT PROTECTION 3
3.3. SYSTEM PHASING-HIGH LEG DELTA SYSTEMS 4
3.4. REMOTE START CONTACT FIELD WIRING 5
3.5. DIELECTRIC TESTING 5
3.6. INSTALLATION OF OPEN TYPE TRANSFER SWITCHES 5
3.7. MOUNTING OF ENCLOSED TRANSFER SWITCHES 5
4. GENERAL DESCRIPTION 8
4.1. PRODUCT MODEL CODE 10
4.2. TYPICAL COMMISSIONING PROCEDURES 11
5. GENERAL THEORY OF OPERATION 11
5.1. STANDARD AUTOMATIC TRANSFER SWITCH 11
5.2. SERVICE ENTRANCE AUTOMATIC TRANSFER SWITCH 12
5.3. TEST MODES 16
6. OVER CURRENT PROTECTION 16
6.1. STANDARD TS 840 AUTOMATIC TRANSFER SWITCH 16
6.2. OPTIONAL TS 840 AUTOMATIC TRANSFER SWITCH WITH INTEGRAL OVER
CURRENT PROTECTION 16
7. GENERAL NOTES ON SERVICING TRANSFER SWITCH MECHANISM 18
8. TRANSFER SWITCH MECHANISM OPERATION–100A-800A, S STYLE20

TS 840 TRANSFER SWITCH
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8.1. MANUAL OPERATION 20
9. RECOMMENDED MAINTENANCE 22
10. FRONT VIEW (TYPICAL) 3 POLE 100A-250A S-STYLE TRANSFER MECHANISM23
11. FRONT VIEW (TYPICAL) 3 POLE 400A-800A S-STYLE TRANSFER MECHANISM
(MECHANISM FRONT COVER REMOVED) 24
12. FRONT VIEW (TYPICAL) 3 POLE 400A-800A S-STYLE TRANSFER MECHANISM25
13. CABLE TERMINAL INFORMATION 26
14. REQUIREMENTS FOR UPSTREAM CIRCUIT PROTECTIVE DEVICES 26
14.1. WITHSTAND CURRENT RATINGS (ALL MODELS WITHOUT INTEGRAL
OVERCURRENT PROTECTION OPTION) 26
14.2. INTERRUPTING CAPACITY CURRENT RATINGS (ALL MODELS WITH INTEGRAL
OVERCURRENT PROTECTION OPTION) 27
15. GROUND FAULT SITE TEST REQUIREMENTS 27
15.1. PERFORMANCE TEST 27
16. TROUBLESHOOTING 29
17. REPLACEMENT PARTS 31
18. PRODUCT RETURN POLICY32
19. NOTES 33
20. PERFORMANCE TEST FORM34

TS 840 TRANSFER SWITCH
PM057 REV 8 10/01/25 1Thomson Technology
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
Rev 0 02/06/17 Original release.
Rev 1 04/11/19 Change Controller From TSC 800 to TSC 80 Controller.
Rev 2 05/03/ 08 Changes to incorporate reversing style ATS Motor for 100-250A
transfer switches.
Rev 3 05/05/17 Revisions to Section 5 and Section 18.
Rev 4 06/05/08 Revisions to Section 15.
Rev 5 07/07/31 Changes to Incorporate new S Style 400A mechanism
Rev 6 08/01/07 Revisions to Appendix A
Rev 7 08/03/05 Changes to Incorporate new S Style mechanism (100A, 150A,
200A, 250A, 600A, 800A)
Rev 8 10/01/25Changes to Incorporate Seismic Certification and Mounting
Requirements
Contact Thomson Technology, 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.thomsontechnology.com.
NOTE: All information contained in this manual is for reference only and is subject
to change without notice.
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.

TS 840 TRANSFER SWITCH
PM057 REV 8 10/01/25 2Thomson Technology
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.
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.

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PM057 REV 8 10/01/25 3Thomson Technology
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 5.2.2 of this manual for additional information on operation of the Transfer
switch following an over current trip condition.
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.

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PM057 REV 8 10/01/25 4Thomson Technology
3.3. SYSTEM PHASING-HIGH LEG DELTA SYSTEMS
For systems using high leg delta 240V 3 phase 4 wire systems, connection of supply
conductors must have the correct phasing as shown below.
WARNING
Failure to match correct system
phasing will result in serious damage
to the TSC 80 controller.
208V
B
(Orange)
(High Leg)
C
(Yellow)
A
(Red)
N
(White)
PH A
(UA)
Automatic Transfer
Switch (Utility Supply)
PH B
(UB) PH C (UC) Neural (N)
120V 120V
240V 240V
Where transfer switches are supplied without power isolation transformers (PT1 &
PT2) for ATS control logic it is essential that the orientation of phase conductors of

TS 840 TRANSFER SWITCH
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the supply source be arranged such that the phase of highest potential with respect
to ground is not connected to the power supply inputs to the controller (A Phase for
both supplies). Failure to do so will result in equipment damage.
Per NEC Article 384-3 (f) “The B phase shall be that phase having the higher
voltage to ground on a 3-phase, 4-wire delta connected systems.”
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
Technology
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.
3.5. DIELECTRIC TESTING
Do not perform any high voltage dielectric testing on the transfer switch with the TSC
80 controller connected into the circuit as serious damage will occur to the controller.
All AC control fuses and control circuit isolation plugs connected to the TSC 80 must
be removed if high voltage dielectric testing is performed on the transfer switch.
3.6. INSTALLATION OF OPEN TYPE TRANSFER SWITCHES
Please refer to the factory for additional information.
3.7. MOUNTING OF ENCLOSED TRANSFER SWITCHES
Model TS840, TS870 and 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.

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"Standard" enclosures are all transfer switch enclosures Thomson Technology 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 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 342%.
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.