Hoshizaki KM-2500SWH3 User Manual

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IV. Service Diagnosis
 WARNING
1. This unit should be diagnosed and repaired only by qualified service 
personnel to reduce the risk of death, electric shock, serious injury, or fire.
2. Risk of electric shock. Use extreme caution and exercise safe electrical 
practices. 
3. Moving parts (e.g., fan blade) can crush and cut. Keep hands clear.
4. 
CHOKING HAZARD: Ensure all components, fasteners, and thumbscrews 
are securely in place after the unit is serviced. Make sure that none have 
fallen into the storage bin.
5. Make sure all food zones in the icemaker and storage bin are clean after 
the unit is serviced. For cleaning procedures, see "VI. Cleaning and 
Maintenance."
A. Diagnostic Procedure 
The diagnostic procedure is basically a sequence check which can be used at unit 
startup or for system diagnosis. This procedure allows you to diagnose electrical system 
and component failures in normal operating conditions of 70°F (21°C) or warmer air and 
50°F (10°C) or warmer water temperatures. Before conducting the diagnostic procedure, 
check for correct installation, proper voltage per unit nameplate, and adequate water 
supply. The maximum allowable voltage variation is ±10 percent of the nameplate 
rating. Check the dip switch settings to assure that S4 dip switch 3, 4, 7, 8, 9, & 10 are 
in the factory default position. S4 dip switch 1, 2, 5, & 6 are cleaning adjustments and 
the settings are flexible. For factory default settings, see "II.C.4.a) Default Dip Switch 
Settings." Check CB using the steps in "IV.B. Control Board Check." As you go through 
the diagnostic procedure, check to assure the components energize and de-energize 
correctly. If not, those components or controls are suspect. Always choose a white (W) 
neutral wire to establish a good neutral connection when checking high voltages.
1) Turn off the power supply, then access the control box. Clear any ice from BC.
2) Turn on the power supply, then move the control switch to the "ICE" position. A 5-second 
delay occurs. The red "POWER OK" LED on CB comes on.
 
3) 
1-Minute Fill Cycle – LED 4 is on. WV energizes. After 1 minute, CB checks for a 
closed F/S. If F/S is closed, harvest cycle begins. If closed, continue to step 4. If open, 
WV remains energized through additional 1-minute fill cycles until water fills the tank 
and closes F/S (low water safety). 
Diagnosis: If WV does not open, check for 115VAC 
at WV terminals. If 115VAC is not present, CB is defective and must be replaced. If 
115VAC is present, check continuity of WV coil, confirm the screen or external filter 
is not plugged (no water flow). If unit fails to start harvest, check for open F/S or bad 
1-minute timer in CB. See "IV.D. Float Switch Check and Cleaning" and "IV.B. Control 
Board Check."