Asco 7000 Series - Testing & Service; Transfer Test; Preventive Maintenance; Replacement Parts

Troubleshooting Installation Manual
381333-415 B 9
TROUBLESHOOTING
Note any optional accessories that may be furnished
on the ATB and review their operation. Refer to any
separate drawings and/or instructions that may be
packed with the ATB.
Table B. Trouble‐Shooting Checks.
Hazardous voltage capable of causing shock,
burns, or death is used in this switch.
Do not touch the power or load terminals
of the bypass switch or transfer switch!
PROBLEM CHECK IN NUMERICAL SEQUENCE
1 OPERATION 2 GEN-SET 3 VOLTAGE
Engine–generator set does
not start when the
Transfer Control switch is
turned and held in Transfer
Test position or when
normal source fails.
Hold Transfer Test switch
15 seconds or the outage
must be long enough to
allow for Feature 1C time
delay plus engine cranking
and startin
g
.
Starting control must be in
the automatic position.
Batteries must be charged
and connected. Check
wiring to engine starting
contacts.
–
Transfer switch does not
transfer the load to the
emergency source after
the engine–generator set
starts.
Wait for Feature 2B time
delay to time out.
Generator output circuit
breaker must be closed.
Generator frequency must
be at least 95% of nominal
(57 Hz for a 60 Hz
s
y
stem.
)
*
Voltmeter should read at
least 90% of nominal
phase to phase voltage
between terminals EA and
EC (or EL1 and EL2 for 2
pole switches
)
*
Transfer switch does not
transfer the load to normal
source when normal
returns or when the
Transfer Control switch is
released.
Wait for Feature 3A time
delay to time out.
– Voltmeter should read at
least 90% of nominal
phase to phase voltage
between terminals NB and
NC, NC and NA, and NA
and NB (or NL1 and NL2
for 2 pole switches
)
.
Gen. does not stop after
load retransfer to normal
source.
Wait for Feature 2E time
delay to time out.
Starting control must be in
the automatic position.
–
7ACTB
Failure to Synchronize
li
g
ht comes on.
Conditions of Normal or Emergency Sources not suitable for closed transition
transfer.
Recheck volta
g
e and frequenc
y
of both sources. Press Alarm Reset pushbutton.
7ACTB
Extended Parallel Time
li
g
ht comes on.
CN and CE contacts are closed longer than setting in the controller. Open the
disconnected source circuit breaker, then call your nearest ASCO Service Center
for assistance.
7ACTB
TS Locked Out
li
g
ht comes on.
Transfer lockout operation has occurred; transfer switch is disabled from automatic
operation. Open the disconnected source circuit breaker, then call your nearest
A
SCO Power Services, Inc for assistance.
7ADTB
Load Disconnect Active
li
g
ht comes on.
Delayed transition transfer operation. If load is disconnected longer than the setting
in Group 5 controller (see User’s Guide 381333–126), then contact ASCO Power
Services, Inc for assistance.
* These are factory settings. Refer to Controller User’s Guide.
If the problem is isolated to circuits on the controller or the transfer switch, call your local ASCO Power
Technologies sales office or ASCO Power Services, Inc at 1–800–800–2726. Furnish the Serial No. and Catalog
No. from the transfer switch nameplate.