GE Industrial Solutions ZBTSCTH SERIES 100 - 4000 AMPS - Manual (Page 15)

ZBTSCTH Operation and Maintenance Manual (46R-7000) Zenith Controls, Inc. 13
SECTION III - MAINTENANCE AND TESTING
(Continued)
4. TROUBLESHOOTING
Before beginning any troubleshooting activity, refer to the information package supplied with the transfer
switch and review the description and operation of all accessories supplied. Also refer to Section II of this
manual, Operation and Features.
CONDITION ITEMS TO BE CHECKED
a. Engine-Generator Does Not Start
when Normal source fails or Test
Switch (TS) is activated.
1) Verify the setting of the time delay P1.
2) Make sure timer P1 drops out and the engine-start
contact closes after time delay is completed.
3) Make sure the starting battery is charged and
connected to the engine-generator.
4) Generator controls in Automatic mode.
5) Verify wiring of the engine-start contact If the generator
does not start, contact the generator dealer.
b. Does Not Transfer To Emergency
after generator starts.
1) If in Closed Transition Mode:
a) Verify that the phase angle difference between
Normal and Emergency is < 5° (@ 0.1 Hz f).
b) Verify that the frequency difference between
Normal and Emergency is < 0.2 Hz (0.1 Hz is
recommended). Also verify that the frequency
difference is not 0 Hz.
c) Verify that the voltage difference between Normal
and Emergency is < ±5% of nominal.
d) Verify that the phase sequence is the same for
Normal and Emergency.
2) Emergency source breaker should be closed.
3) Emergency source voltage and frequency should meet
the preset pickup values of the VFSM relay.
4) Make sure Emergency control relay RT picks up after
time delay W.
c. Does Not Retransfer To Normal
when Normal source restores or
Test Switch (TS) is deactivated.
1) If in Closed Transition Mode:
a) Verify that the phase angle difference between
Normal and Emergency is < 5° (@ 0.1 Hz f).
b) Verify that the frequency difference between
Normal and Emergency is < 0.2 Hz (0.1 Hz is
recommended). Also verify that the frequency
difference is not 0 Hz.
c) Verify that the voltage difference between Normal
and Emergency is < ±5% of Nominal.
d) Verify that the phase sequence is the same for
Normal and Emergency.
2) Normal source voltage should meet the preset pickup
value of the phase relays.
3) Make sure Normal control relay CR picks up after time
delay T.
4) Verify the circuit connections from the power relay, CN1
or CCN, to the Normal switch operating circuit.
5) Verify the circuit connections from the power relay, CE1
or CCE, to the Emergency switch operating circuit.
d. Engine-Generator Does Not
Shutdown after retransfer to
Normal.
1) Verify the setting of engine overrun time delay U.
2) Make sure timer P1 picks up and the engine-start
contact has opened.
3) Generator controls in Automatic mode.
4) Verify wiring of the engine-start contact.