Control Board Alarms (Ea And Ed); Service Chart; No Operation - Hoshizaki REFRIGERATED PREP TABLE WITH RAISED RAIL 73168 Service Manual

7. Control Board Alarms (EA and ED)

"EA" is displayed when an EEPROM write error is detected. "ED" is displayed when an
EEPROM verification or read error is detected.
Reset Options
Replacing the control board with a functioning control board will eliminate this alarm
condition.
B. Service Chart

1. No Operation

Problem
[1] The unit will not
start.
[2] Cabinet, rail, or
condenser fan will
not start.
[3] Compressor will
not start or stops
operating.
Possible Cause
a) Power Supply
b) Cord and Plug
c) Control Switch
d) Transformer
e) Wiring to Control Board 1. Loose connections or
f) Control Board
a) Fan Motor
b) Evaporator Fan, Rail
Fan, or Compressor
Relay
c) Control Board
a) Compressor Relay
b) Compressor Control
Relay
c) Start Relay
d) Start Capacitor
e) Wiring to Compressor
1. Unplugged, off,
blown fuse, or tripped
or defective circuit
breaker.
2. Loose connection.
3. Not within
specifications.
1. Defective.
1. "OFF" position.
2. Bad contacts.
1. Open coil winding.
open.
1. In alarm.
2. Defective.
1. Motor winding open.
2. Bearing worn out.
3. Wiring to fan motor.
4. Fan blade bound.
1. Bad contacts.
2. Coil winding open.
1. Defective.
1. Bad contacts.
1. Bad contacts.
2. Open winding.
1. Bad contacts.
2. Coil winding open.
1. Defective.
1. Loose connection(s).
2. Faulty.
33
Remedy
1. Turn on, replace, or check
and reset. Call electrician if
breaker trips repeatedly.
2. Tighten.
3. Refer to nameplate and
correct.
1. Replace.
1. Move to "ON" position.
2. Check for continuity and
replace.
1. Check continuity and
replace.
1. Check for continuity and
replace.
1. See "III.A. Alarm Signals."
2. Replace.
1. Replace.
2 Replace.
3. Check for loose or open
connection, and replace.
4. Check and replace.
1. Check for continuity and
replace.
2. Replace.
1. Replace.
1. Check for continuity and
replace.
1. Check for continuity and
replace.
2. Replace.
1. Replace.
2. Replace.
1. Check and replace.
1. Tighten.
2. Check continuity and
replace.