Hoshizaki IM-500SAB Service Manual page 11

2) Harvest Cycle: Comp 30-sec. delay timer terminates, 20-sec. WV delay timer starts,
Comp and AMD (opening) energize. HGV continues. 20-sec. WV delay timer terminates,
WV energizes. 30 sec. WV on timer starts. AMD de-energizes when AMPS activates
at water tank fully open position. Once ET reaches 41°F (5°C), HGV de-energizes, FM
and AMU (closing) energize. 30-sec. WV on timer terminates, WV de-energizes.
AMU de-energizes when AMPS activates at water tank fully closed position.
WV energizes. 144-sec. on timer starts (when WT > 48°F (9°C)). Note: HGV
de-energizes when ET reaches 41°F (5°C). During a start up scenario this occurs at
same time AMU (closing) and FM energize. Evap starts cooling before harvest cycle is
complete. Harvest cycle is complete once AMPS indicates water tank is fully closed.
a) Comp Diagnosis: Check that Comp energizes and evaporator is warming. If not,
check for 115VAC at CB CN3 #9 orange (O) to neutral (W). If 115VAC is not present,
check for 115VAC at CB CN2 #3 red (R) to neutral (W). If 115VAC is not present,
check CS terminal #2 (DBU) to neutral (W). If 115VAC is not present, check 5A
fuse and breaker status. If 115VAC is present at CS terminal #2 (DBU) to neutral
(W) and not at CS terminal #3 red (R), replace CS. If 115VAC is present at CB CN2
#3 red (R) and not at CB CN3 #9 orange (O), replace CB. If 115VAC is present at CB
CN3 #9 orange (O), check for 115VAC at CR solenoid. If 115VAC is present, confirm
contacts are closed. If not, replace CR. If CR contacts are closed, check Comp
external protector, Comp start and run capacitors, Comp start relay, and Comp
motor winding.
b) HGV Diagnosis: If Comp is energized and evaporator is not warming, check that
HGV energizes and opens. Check for 115VAC at CB CN3 #3 (P) to neutral (W).
If 115VAC is not present, replace CB. If 115VAC is present, check for 115VAC at
HGV coil and check HGV coil continuity. Replace as needed.
c) AMD Diagnosis: AMD energizes (opens). If not, check for 115VAC at CN5 #3 (GY)
to neutral (W). If 115VAC is not present, replace CB. If 115VAC is present, check AM
actuator arms for binding, spring connections, capacitor, and motor windings.
If AMPS does not indicate water tank is fully open within 3 min. display shows "EE"
and unit shuts down for 60 min. If error recurs after icemaker resumes operation,
display shows "EE" again and icemaker shuts down. See "III.F. Error Codes."
d) WV Diagnosis: 20-sec. WV delay timer terminates. WV energizes. 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. C heck for 115VAC at CB CN3 #7
(V) 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 30-sec. WV on timer terminates and WV does not
de-energize, check for 115VAC at CB CN3 #7 (V) to neutral for 115VAC. If 115VAC
is present (WV does not de-energize during harvest), replace CB. If 115VAC is not
present, check for WV leaking by. Clean or replace WV.
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