Technicolor - Thomson POWER & CONTROL TS 870 - Manual (Page 15)

TS 870 TRANSFER SWITCH
PM062 REV 8 10/01/25 11 Thomson Technology
4.2. TYPICAL COMMISSIONING PROCEDURES
CAUTION:
Commissioning procedures must be performed by qualified
personnel only. Ensure the Automatic Transfer Switch
(ATS) Control Circuit Isolation Plug is 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 870 (attached as “Appendix A ”) is provided for
general information only pertaining to typical site installations and applications. Contact
Thomson Technology for further information as may be required.
5. GENERAL THEORY OF OPERATION
5.1. STANDARD AUTOMATIC TRANSFER SWITCH
5.1.1. NORMAL OPERATION
When utility supply voltage drops below a preset nominal value (adjustable from
70% to 100% 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 60 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 levels. Once the generator voltage and frequency rises
above preset values (adjustable from 70% to 95% of nominal), the engine warm-up
timer will be initiated. Once the warm-up timer expires (adjustable from 0 to 60
sec.), 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 driven mechanism.