Evaporator Is Frozen Up - Hoshizaki KMD-900MRH Service Manual

Problem
[7] Continued from
previous page.

2. Evaporator is Frozen Up

Problem
[1] Freeze cycle time is
too long.
[2] All ice formed on
evaporator does not
fall into bin in harvest
cycle.
[3] Other
Possible Cause
e) Water Supply Line
[Water-cooled model
only]
Possible Cause
a) Float Switch
b) Water Solenoid Valve
c) Controller Board
a) Evaporator
b) Water Supply Line
c) Water Solenoid Valve
d) Ambient and/or water
temperature.
e) Line Valve
f) Thermistor
g) Controller Board
a) Spray Tubes
b) Water System
c) Refrigerant
d) Expansion Valve
e) Hot Gas Solenoid
Valve
1. Condenser water pressure
too low or off and pressure
control opens and closes
frequently.
1. Leads short-circuit or
defective switch.
2. Float does not move
freely.
1. Diaphragm does not close. 1. Check for water leaks with
1. Defective.
1. Scaled up.
1. Water pressure too low.
1. Dirty mesh filter or orifice. 1. Clean.
2. Diaphragm does not close. 2. Check for water leaks with
1. Too cool.
1. Continues to open in
harvest cycle.
1. Out of position or loose
attachment.
1. Defrost timer is set too
short.
2. Defective.
1. Clogged.
2. Out of position.
1. Dirty.
1. Undercharged.
1. Bulb out of position or
loose attachment.
2. Defective.
1. Coil winding opened.
2. Plunger does not move.
3. Wiring to hot gas valve.
55
Remedy
1. Check and get
recommended pressure.
Remedy
1. Check and replace.
2. Clean or replace.
icemaker off.
1. See "II.2[e] Checking the
Controller Board."
1. Clean.
1. Check and get
recommended pressure.
icemaker off.
1. Increase temperature.
1. Check operation in harvest
cycle and replace.
1. See "V.11. Removal and
Replacement of
Thermistor."
1. Adjust longer, referring to
"II.2.[d] Controls and
Adjustments, 2) Defrost
Timer."
2. See "II.2[e] Checking the
Controller Board."
1. Clean
2. Place in position.
1. Clean.
1. Check for leaks and
recharge.
1. Place in position.
2. Replace.
1. Replace.
2. Replace.
3. Check for loose
connection or open, and
replace.