Hoshizaki KM-320MAH Service Manual page 27

6) Freeze Cycle – LED 1 is on. Comp, FMR, and PM continue. FM and LLV energize.
HGV and X10 relay de-energize. Appliance is held in freeze by a 5-min. short cycle
protection timer. After 5-min. timer terminates and FS opens, freeze cycle terminates.
Note: PM power supply switches from CB K1 #5 (DBU) in harvest to K1 #4 (R) in freeze.
a) Freeze Cycle Diagnosis: Confirm Comp, FMR, and PM continue. Confirm that
FM and LLV energize. Confirm WRV opens. Next, confirm HGV and X10 relay
de-energize. During the first 5 min. of freeze, confirm evaporator is cooling. If not,
confirm WV de-energized (not leaking by), HGV de-energized (not bypassing),
LLV and FM energize, TXV and HM operate correctly, WRV opens, Comp is
efficient, and refrigerant charge is correct. See "VIII.A. Specification Sheet" and
"VIII.B. Performance Data."
b) Comp and FMR Diagnosis: If Comp and FMR de-energize once freeze begins,
check that appliance has not shut off on HPS ("POWER OK" LED off). If so, check
"3)b) HPS Diagnosis" above. If "POWER OK" LED is on, check for 115VAC at CB K1
#1 (V) or #9 (V) to neutral (W). If 115VAC is not present and LED 1 is on, replace CB.
If 115VAC is present, check for 115VAC at CR or MC coil. If 115VAC is present, check
CR or MC coil and contact continuity. Replace as needed. If CR or MC is okay, check
Comp start relay and start and run capacitors. Next, check Comp motor winding
continuity. If Comp is energized but evaporator is not cooling, check for an inefficient
Comp. See "VIII.B. Performance Data." If Comp is energized but FMR is not, check
for 115VAC at the FMR junction box. If 115VAC is not present, check icemaker wiring
connections. If 115VAC is present, check for voltage at condenser unit. If 115VAC
is not present, check field wiring connections. If 115VAC is present, check FMR
capacitor, motor winding, and fan blade for binding.
c) WV and HGV Diagnosis: If WV is energized, check for 115VAC at CB K1 #6 (O) to
neutral (W). If 115VAC is present after PM energizes in harvest cycle, replace CB.
If 115VAC is not present, replace WV (bypassing). If HGV did not de-energize at
the end of harvest, check for 115VAC at CB K1 #2 (P) to neutral (W). If 115VAC is
present 50 sec. after PM energizes, replace CB. If 115VAC is not present, replace
HGV (bypassing).
d) PM Diagnosis: Confirm water is flowing over evaporator from PM and not WV. If PM
de-energizes once freeze begins, check for 115VAC at CB K1 #4 (R) to neutral (W).
If 115VAC is not present, replace CB. If 115VAC is present and PM is de-energized,
check for 115VAC at control switch #5 (R) to neutral (W). If 115VAC is present at CB
K1 #4 (R) and not at control switch #5 (R), check control switch continuity between
#5 (R) and #4 (R). Replace as needed. If 115VAC is present at control switch #5 (R)
to neutral (W), check PM capacitor and motor winding continuity.
e) FM and LLV Diagnosis: If FM or LLV does not energize, check for 115VAC at CB
K1 #3 (BK) to neutral (W). If 115VAC is not present, replace CB. If 115VAC is present:
For FM, check capacitor, motor winding, and blade for binding.
For LLV, check coil voltage and continuity.
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