Hoshizaki KM-350MWJ Service Manual page 18

5c) Initial Harvest Cycle Termination Diagnosis: When the thermistor reaches 48°F
(9°C), CB reads 3.9 kΩ from the thermistor and turns harvest termination over to
the harvest timer (S4 dip switch 1 & 2 and S5 dip switch 4). Check discharge line
temperature. For a thermistor check, see "II.F. Thermistor Check." If 1-min. fill cycle
starts after harvest timer terminates, check that FS is clean and operating properly, see
"II.E. Float Switch Check and Cleaning." If FS is closed, CB proceeds to the next cycle.
If not, replace CB.
Note: The minimum total time allowed by CB for a complete harvest cycle is based on
S5 dip switch 4. Maximum harvest time allowed is 20 min.
NOTICE! S4 dip switch 7 must remain on. Otherwise, PM will not energize during
the last seconds of harvest.
6) Freeze Cycle – LED 1, 2, and 3 are on. Comp, FMR, and PM continue. FM and
LLV energize. HGV de-energizes. Appliance is held in freeze by a 5-min. short cycle
protection timer. After 5-min. short cycle protection timer terminates and FS opens,
freeze cycle terminates.
Note: PM power supply continues from CB K1 #4 (R) in harvest and in freeze.
Anti-Slush: When anti-slush is enabled (S5 dip switch 5 "ON"), PM de-energizes when
thermistor reaches 36°F (2.2°C) (5.8 kΩ) for 10 sec. then, energizes for the remainder
of the freeze cycle.
a) Freeze Cycle Diagnosis: Confirm Comp, FMR, and PM continue. Confirm that FM
and LLV energize. Confirm WRV opens. Next, confirm HGV de-energizes.
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 and Performance Data
Sheets."
b) Comp and FMR Diagnosis: If Comp and FMR de-energize once freeze begins,
check that appliance has not shut off on HPS (CB "POWER OK" LED off). If so,
check "3)b) HPS Diagnosis" above. If CB "POWER OK" LED is on, check for 115VAC
at CB K1 #9 (Y) to neutral (W). If 115VAC is not present and LED 1 is on, replace CB.
If 115VAC is present, check for 115VAC at CR coil. If 115VAC is present, check CR
coil and contact continuity. Replace as needed. If CR 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.A. Specification and Performance Data Sheets." 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 and LED 2 is on, replace CB. If 115VAC is not present, replace HGV
(bypassing).
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