Diagnostic Chart; Unit Not Cooling - Hoshizaki Commercial Series Service Manual

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D. Diagnostic Chart

1. Unit Not Cooling

Problem
[1] Unit does not
start.
[2] Evaporator fan
does not start.
[3] Cool down
does not start.
(compressor)
Possible Cause
a) Power Supply
b) Cord and Plug
c) Power Switch (control box) 1. "OFF" position.
d) Wiring
e) Control Module
a) Door Switch
b) Door Switch Relay
c) Control Module (freezer)
d) Evaporator Fan Motor
a) Setpoint
b) Control Module
c) High-Pressure Switch
d) Compressor Relay
(freezer)
1. Unplugged, off, blown fuse,
or tripped or defective circuit
breaker.
2. Loose connection.
3. Not within specifications.
1. Defective.
2. Bad contacts.
1. Loose connection or open.
2. Faulty.
1. In alarm or "- - -" displayed.
2. Defective.
1. Defective.
1. Power supply not within
specifications.
2. Bad contacts.
3. Open coil windings.
1. Defective.
1. Defective.
1. Incorrect.
1. In alarm or "- - -" displayed.
2. Defective.
1. Bad contacts.
2. Dirty air filter or condenser.
3. Ambient temperature too
warm.
4. Refrigerant overcharge.
5. Condenser fan not operating. 5. Replace.
6. Refrigerant lines or
components restricted.
1. Bad contacts.
2. Open coil windings.
30
Remedy
1. Plug in, turn on, replace, or reset.
2. Tighten.
3. Refer to nameplate and correct.
1. Replace.
1. Move to "ON" position.
2. Check for continuity and replace.
1. Tighten, check for continuity and
repair.
2. Check for continuity and replace.
1. See "II.D.2. Alarm Safeties."
2. See "IV.B. Control Module
Check."
1. Check for continuity and replace.
1. Refer to nameplate and correct.
2. Check for continuity and replace.
3. Replace.
1. See "IV.B. Control Module
Check."
1. Replace.
1. Correct setpoint. See "II.C.2.a)
Default Settings."
1. See "II.D.2. Alarm Safeties."
2. See "IV.B. Control Module
Check."
1. Check for continuity and replace.
2. Clean.
3. Reduce temperature.
4. Recharge. See "V.A. Service for
Refrigerant Lines."
6. Recover, repair, replace drier,
evacuate, and recharge. See
"V.A. Service for Refrigerant
Lines."
1. Replace.
2. Replace.