Onan LTC Series - Page 22

TROUELE
Powet
fails,
plant
start.
does
not
t.
TROUBTE-SHOOTING
CHART
POSSIBLE CAUSE
TROUBLE
If
time
delay on
starti
Will
not
exercise.
included,
check
to see
that normal delay
has Does
not
stop at
exercise
period.
POS5IELE CAUSE
l.
Defective
exerciser.
Exerciser
fails
during
period.
Power failure
during
exercise
period.
Dirty
or
pitted
contacts
on
bansfer
switch.
Defective transfer
switch
line s
ide
coil.
Transfer switches elec-
trical
interlocking
switches
def ective.
Instant
transfer relav
defective.
If
time
delay
on load
pickup
included, check
to
see
that normal delay
has
occurred.
No
generator
voltage
build-up
or
low
gen-
erator
output voltage.
Defective
transfer
switch
pilot
relay.
Defective
latch
mechan-
ism on
hansfer
switch
-
line
side
not unlatching.
If
time
delay
on
retrans-
fer is inc:luded,
be
sure
normal dr:lay
periotl
has
passed.
Defective
transfer
switch coil.
Defective
instant
trans-
fer relay
Transfer
switch mech-
anical
interlock
defec-
tive
or
generator
con-
tacts not completely
dropped out
Iilectrical
interlock
switches defective.
I.
Transfer
switch not
latching
into
closed
position
-
adjust.
(See
Troubleshooting
and
Rrpair
Section)
Mech-
anically
Held Only
end of
l.
2.
l.
2.
3.
4.
1.
2.
3.
3.
4.
2.
3.
1.
1.
2.
occurred.
Defective
time
delay
on
starting
rclay.
Generating
plant
defec-
tive.
No
power
to
load
normal operation.
during
4.
Start-stoo relav
stickinp
or
dirty
contacts.
Plant
starts under
noeppar-
ent
power
failure.
No delay on
shrting.
Plant does not react
to
low
low voltage.
Plant
does not
strrp when
power
returns
-
conUnues
to supply
power
to load.
Equipped with
voltage
sensitive
relays
but no
delay on
starting.
Mo
mentary voltage
dips
will cause a control
so
equipped to
start.
Defecti ve volta
ge
se ns i-
tive relays.
Defectjve start-stop
relay.
Defective
time
delav on
starting relay.
Defective
voltage
sen-
sitive relays.
Voltage
sensitive relay
requires
adjustment.
If
time
delay on
stop-
ping
included,
check
to
see
that normal
delav
has
occurred.
Time
de
lay on retransfer
relay
defective.
Defective voltage
sen-
sitive relay
(will
not
pickup).
No
power
to
load after
generator
start.
Line sideof transfer
switch
does notpickup
when
power
ret
urn s.
Transfer
switch
chatters
wh,:n
line
power
returns.
1.
l.
2.
3.
3.
4.
No
delay on
stopping.
1.
Defective time
delay on
stopping
relay.
Plant
continues
to
run aftet
transfering
load
back to
oommerciel
power.
If
time
delay
on
st,rp
ping
(after
hansfer)
is
included,
be
sure
nor-
mal
delay has passed.
Defective
tine
delarv
on
stopping
relay.
Defective
s
tart-stop
re-
lay
(will
not
energize').
Short in
plant
to load
hansfr-,r contml
wires.
l.
3.
4.