Hoshizaki KM-81BAJ Service Manual page 16

1. Sequence and Component Diagnosis
3) Power On: Plug the appliance into the electrical outlet. Move the control switch to the
"ICE" position. A 5-sec. delay occurs. CB red "POWER OK" LED turns on.
Note: • CB red "POWER OK" LED remains on unless the 10.5VAC power supply is
interrupted (K2 connector).
• Check CB using the steps in "II.C. Control Board Check."
• Confirm CB red "POWER OK" LED is on. If CB red "POWER OK" LED is flashing
(indicating a full bin), check BC. Move ice away from BC actuator paddle. If CB
red "POWER OK" LED continues to flash, see "II.D.1. Bin Control Check."
a) Power On Diagnosis: If CB red "POWER OK" LED is off, confirm 5A fuse is good.
Check for 115VAC at control switch #5 (GY) to neutral (W) then at control switch
#4 (P) to neutral (W). If 115VAC is present on #5 (GY) and not on #4 (P), replace
control switch. If 115VAC is present on control switch #4 (P), check for 115VAC at
HPS (P) (KM-161 Models) to neutral (W) then HPS (BR) to neutral (W). If 115VAC is
present at HPS (P) and not at HPS (BR), HPS is open. See HPS Diagnosis below.
If 115VAC is present at HPS (BR), check for 10.5VAC at CB K7 #1 red wire to CB K7
#2 red wire. If 10.5VAC is not present, check CT continuity. If open, replace CT.
b) HPS Diagnosis (KM-161B_J): Check that the condenser coil is not clogged or
restricted. Let refrigeration circuit pressures equalize. If HPS does not reset and
pressures are equalized, replace HPS. If pressures are not equalized, reclaim
refrigerant and diagnose refrigeration circuit restriction. Check that there are no
restrictions in the refrigeration circuit.
Harvest Cycle: HGV, strainer, or check valve.
Freeze Cycle: FM, TXV, WRV, strainer, and drier.
Confirm that the location meets installation requirements:
• The appliance is not intended for outdoor use. Normal operating ambient temperature
should be within 45°F to 100°F (7°C to 38°C).
• Allow 2" (5 cm) clearance on the right side and 5/8" (15 mm) clearance at the top
for proper air circulation and ease of maintenance and/or service should they be
required.
• The appliance should not be located in a corrosive environment.
4) 1-Min. Fill Cycle – LED 8 is on. WV energizes. After 1 min., CB checks for a closed
FS. If FS is closed, the harvest cycle begins. If harvest cycle begins (Comp, HGV,
energized), continue to step 5a. If FS is open, WV remains energized until FS closes
(low water safety protection during initial start up and at the end of each harvest).
Diagnosis: Check that water enters the water tank. If not, check that the water supply
line shut-off valve is open and screens or external filters are clear. Check for 115VAC
at CB K5 #4 (O) to neutral (W). If 115VAC is not present, replace CB. If 115VAC is
present, and WV does not energize, check for 115VAC at WV. If 115VAC is present,
check coil continuity. If open, replace WV. If the water tank fills, but the appliance fails to
start harvest (Comp energized), check for open FS. See "II.E. Float Switch Check and
Cleaning." If FS is closed and CB fails to start the harvest cycle after 1 min., replace
CB.
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