Hoshizaki IM-500SAB Service Manual page 12

3) Freeze Cycle: AMPS activated (water tank completely closed). 60-sec. PM delay timer
starts (initial startup; 60-sec. PM delay timer, normal operation; 30-sec. PM delay timer).
WV energizes and 144-sec. WV on timer starts (initial startup; 144-sec. WV on timer,
normal operation 52-sec. WV on timer). Comp and FM continue. Evaporator cooling.
Once PM delay timer terminates, PM energizes. 44 sec. (or 22 sec.) later WV on timer
terminates, WV de-energizes.
a) AMU Diagnosis: AMU completes its rotation and AMPS is activated. If AM does
not rotate up, check for 115VAC at CB CN5 #1 (O) to neutral (W). If 115VAC is not
present, confirm ET is at 41°F (5°C) or higher. If ET achieved and AM does not
energize, replace CB. If 115VAC is present, check AM actuator arms for binding,
actuator springs for proper connection, capacitor, and AM motor windings. Repair or
replace as needed. If AMPS does not indicate water tank is fully closed 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."
b) Freeze Cycle Diagnosis: If Comp de-energizes once freeze begins, check
that appliance has not shut off on HPS ("on" display off). If so, check "1)b) HPS
Diagnosis" above. If "on" display is on, check for 115VAC at CB CN3 #9 (O) to
neutral (W). If 115VAC is not present, replace CB. Confirm Comp and FM continue.
Confirm that PM energizes after PM delay timer terminates. Confirm evaporator is
cooling. If not, confirm HGV de-energized (not bypassing) and FM energizes, TXV
operating correctly, Comp is efficient, and refrigerant charge is correct. See "VIII.A.
Specification and Performance Data." Note: Refrigerant gauges should not be placed
on the icemaker until all other components have been confirmed.
c) Comp Diagnosis: If Comp is not energized, check for 115VAC at CB CN3 #9 (O).
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 HGV leaking by or an inefficient
Comp. See "VIII.A. Specification and Performance Data."
d) FM: If Comp is energized but FM is not, check for 115VAC at CB CN3 #5 (DBU) to
neutral. If 115VAC is not present, replace CB. If 115VAC is present, check capacitor,
motor winding, and fan blade for binding.
e) PM: Confirm water is flowing over evaporator. If not, check for 115VAC at CB CN3
#1 (BK) to neutral (W). If 115VAC is not present, replace CB. If 115VAC is present
and PM is de-energized, check PM impellar for binding, capacitor, and motor winding
continuity.
f) WV Diagnostics: WV energizes, 144-sec. or 52-sec. WV on timer starts. 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. 144-sec. or 52-sec. WV on timer terminates. WV de-energizes.
If WV continues, check for 115VAC at CB CN3 #7 (V) to neutral (W). If 115VAC is
present, and WV on timer time has expired, replaced CB . If WV de-energizes and
water continues to fill the reservoir, replace WV.
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