Hoshizaki TempGuard FH1-SSB, Service Manual, Page: 27 / 63

7
III. Service Diagnosis
A. Diagnosis Chart
Problem Possible Cause Remedy
[1] Compressor will
not start—no
current draw.
a) Power Supply
1. "OFF" position. 1. Move to "ON" position.
. Loose connection. . Tighten.
3. Failure. 3. Call electrician.
4. 08/30 volt; wrong leg to
power control board.
4. Correct wiring.
b) Cord and Plug 1. Defective. 1. Replace.
c) Ground Fault Circuit
Interrupter
1. Tripped. 1. Check and reset.
. Defective. . Replace.
d) Transformer 1. Open coil winding. 1. Check continuity and replace.
e) Wiring to Control Board 1. Loose connection. 1. Tighten.
. Faulty. . Check continuity and replace.
f) Voltage 1. Too low. 1. Call electrician.
. Too high. . Call electrician.
3. 08/30 volt; wrong leg to
power control board.
3. Correct wiring.
g) High Pressure Switch 1. Bad contacts. 1. Check continuity and replace.
. Has operated 5 or more times
in one hour. (E4 should be
displayed)
. Press "RESET" on control board.
Determine why pressure switch
is activated.
h) Thermistor 1. Defective. 1. Replace.
i) Control Board 1. Defective. 1. Replace control board.
j) Compressor Overload 1. Defective. (Contacts open) 1. Replace.
k) Compressor 1. Open windings. 1. Check continuity and replace.
l) Relay (Condensing Unit) 1. Bad contacts. 1. Replace.
. Open coil winding. . Check and replace.
[] Compressor will
not run—draws
current and trips
on overload.
a) Voltage 1. Too low. 1. Call electrician.
b) Start Relay 1. Bad contacts. 1. Replace.
. Open coil windings. . Replace.
c) Compressor 1. Locked rotor. 1. Replace.
d) Start Capacitor 1. Defective. 1. Check and replace.
[3] Compressor runs
intermittently
and trips on
overload.
a) Voltage 1. Too low. 1. Call electrician.
. Too high. . Call electrician.
b) Condenser Filter 1. Clogged. 1. Clean filter.
c) Refrigerant Line or
Component
1. Plugged or restricted. 1. Clean and replace drier.
d) Condenser Fan Motor 1. Failed 1. Replace.
e) Refrigerant 1. Overcharged. 1. Evacuate and recharge.
. Non-condensibles in system. . Evacuate and recharge.
f) Location of Unit 1. Restricted air flow to
condenser.
1. Move unit or increase ventilation.
g) Boards not
Communicating (Dual
Temp units only)
1. Communication
disconnected.
1. Restore communication.
. Wrong dip switch setting; #6
off, either board.
. Turn #6 on.