Hoshizaki KM-901MAJ Service Manual page 22

FM and LLV de-energize. PM stops for 2 sec., then reverses for 10/20 sec. depending
on pump-out timer (S4 dip switch 3 & 4) setting. When the pump-out timer terminates,
pump-out is complete. The pump-out frequency control (S4 dip switch 5) is factory set,
and generally no adjustment is required. However, the pump-out frequency control can
be set to have a pump-out occur every 10 cycles or every cycle. For details, see "III.C.4.
Pump-Out Frequency Control (S4 dip switch 5)."
Pump-Out Diagnosis: In the freeze cycle before pump-out (see table above), after
5 min. of freeze disconnect CB black K5 connector (FS connector). Check that PM
stops and re-starts. Next, check that PM rotation is correct (water flowing down the
drain through CV). If PM does not stop and re-start, check that CB LEDs 1, 3, and 2
are on. If not, replace CB. If LEDs 1, 3, and 2 are on and PM does not energize, check
for 115VAC at CB K1 #5 (DBU) to neutral (W). If 115VAC is not present, replace CB.
If 115VAC is present, check that X10 relay is de-energized. If not, check X11 relay
status. If X11 relay is energized, replace CB. If X11 relay is de-energized and X10 relay
is energized, replace X11 relay (contacts sticking). If X10 relay is de-energized, check
for 115VAC at terminal #6 (DBU) to neutral (W) and terminal #2 (DBU) to neutral (W).
If 115VAC is present on terminal #6 (DBU) and not on terminal #2 (DBU), replace
X10 relay. If 115VAC is present on X10 terminal #2 (DBU) and PM is not energized
check for 115VAC at X12 terminal #6 (DBU) to neutral (W) and X12 terminal #4
(DBU) to neutral (W). If 115VAC is present on X12 terminal #6 (DBU) and not on X12
terminal #4 (DBU), check for 115VAC at X12 terminal #7 (P) to X12 terminal #8 (W). If
115VAC is not present, check CB K1 pin #2 (P) wiring for loose connection. If 115VAC
is present and X12 is not energized, check coil continuity. Replace as needed. If X12
is energized and X12 terminal #4 (DBU) does not have 115VAC, replace X12 relay
(contacts sticking). If X12 terminal #4 (DBU) has 115VAC, PM should be energized and
rotating in pump-out rotation. If not, check PM motor windings and impeller for binding.
If energized and rotating correctly, make sure the drain line is not clogged and that CV
is clean and operating properly.
Confirm FM and LLV de-energize. If FM or LLV are energized with LEDs 1, 3, and 2 on,
replace CB.
8) Normal Harvest Cycle – Same as the initial harvest cycle. Return to step 5a) above.
Note: Appliance continues to cycle until MBC is satisfied or power is switched off. The
appliance always restarts at the 1-min. fill cycle.
2. Shutdown
1) See "II.E.Bin Control Check."
3. Freeze-Time Correction Cycle Diagnosis (CB 2A7664-02)
1) See "II.C. Freeze-Time Correction Cycle."
Legend: BC–bin control; CB–control board; Comp–compressor; CV–check valve;
FM*-FM–fan motor; FMR–fan motor remote; FS–float switch; HGV–hot gas valve;
HM–headmaster (C.P.R.); HPS–high-pressure switch; LLV–liquid line valve;
MBC–mechanical bin control; PM–pump motor; TXV–thermostatic expansion
valve; WRV–water regulating Valve; WV–inlet water valve
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