Onan MCCK - CONTROL-O-MATIC TROUBLE SHOOTING

CONTROL-O-MATIC TROUBLE SHOOTING
1. Control switch is in “RUN” position, but electric
plant does not crank after the usual 5-minute delay
period.
a. Check battery connections and battery voltage.
b. Remove the lead on thermal relay A2K.1 (move
lead wire from terminal 1, to terminal 3, Fig. 17)to
disable the bilge-blower control. If pl-ant cranks
with the bilge blower control disabled, the prob¬
lem is in the bilge blower control circuit. Refer
to paragraph 5.
2. Electric plant will not start on load demand.
a. Move the toggle switch to “RUN” position. Plant
should crank after approximately a 5-minute delay.
b. Apply some load (at least 100 watts) to load cir¬
cuit. Move toggle switch to ”AUTO” position.
Plant should continue running.
3. Control-O-Matic starts plant automatically under load,
but slows down or stops as soon as contactor picks up.
a. Recheck size of load and type of load to make cer¬
tain it exceeds 40 W incandescent lamp load or
425 W heater load.
4. Plant won’t stop with load removed.
a. Put toggle switch in “OFF” position to stop plant.
If plant does not stop, remove battery lead and
check for faulty start solenoid. Contacts may have
stuck closed.
b. Remove the load from the load side of the contactor
in Control-O-Matic.
c- Put toggle switch in “AUTO” position.
If plant does not crank, put toggle switch in “RUN”
position to start plant. Put switch in “AUTO”
position and plant should stop. If plant stops with
the load lead removed from the load side of the
contactor, it indicates that there was sufficient
load on the AC line to keep the Control-O-Matic
energized. Recheck load circuit.
5. B ilge-blower Control.
a. Bilge-blower circuit does not function at all.
Check the 6-1/4 amp fuse A2F1.
b. Blower circuit is energized continuously and elec¬
tric plant doesn’t crank.
Check heater element of thermal relay for open
circuit or poor connection which may prevent relay
from heating up enough to switch.
c. Blower circuit is not energized, but plant starts
after a 2- to 6-minute delay.
Check operation of blower by placing a jumper
from terminal BB to ground. Blower should run.
If it doesn't, check for proper voltage from ground
to terminal B+. Check wiring to blower.
Your Onan dealer is equipped to service the Control-O-
Matic. The Service Manual for this generating plant con¬
tains complete Trouble-shooting information.
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