TS 880 TRANSFER SWITCH
PM064 REV8 10/01/25 13 Thomson Technology
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
power switching device) to the generator 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 the present values (70 - 99% of rated adjustable) 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 via external logic device. 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 is transferred from
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.
To Next Page
Loading...
