Led Lights And Audible Alarm Safeties; K Control Board (2A8242-02) - Hoshizaki KM-420MWJ Service Manual

B. LED Lights and Audible Alarm Safeties

1. K Control Board (2A8242-02)

Beep occurs and red CB "POWER OK" LED turns on when control switch is moved to
"ICE" position.
Green LEDs 1 through 5 turn on and sequence from initial startup as listed in the table
below. Order of green LEDs from the outer edge of control board is 1, 4, 5, 3, 2.
Sequence Step
1-Minute Fill Cycle
Harvest Cycle
Harvest Pump Time
(harvest assist)
Freeze Cycle
Anti-Slush Control
Pump-Out Cycle
*pump-out timer setting
Type
1 High Evaporator Temp.
Beep (temperature > 127°F) (53°C)
2 Harvest Backup Timer
Beep (harvest > 20 min. for two
cycles in a row)
3 Freeze Timer
Beep (freeze > freeze timer setting
for two cycles in a row)
To reset above safeties, press "ALARM RESET" button with power supply on.
6 Low Voltage
(92Vac±5% or less)
7 High Voltage
(147Vac±5% or more)
Legend: Comp–compressor; DV–drain valve; FM–fan motor; FMR–fan motor remote;
FS–float switch; HGV–hot gas valve; HM–headmaster (C.P.R.); LLV–liquid line
valve; PM–pump motor; TXV–thermostatic expansion valve; WRV–water regulating
valve; WV–inlet water valve
Sequence
LED
4 WV
1, 4 Comp, FMR, HGV, WV
1, 3 Comp, FMR, HGV, PM
1, 2, 3 Comp, FM/FMR, PM, LLV
1, 2 Comp, FM/FMR, LLV
1, 4 , 5, 3 Comp, FMR, HGV, PM, WV*, DV
*
Alarm
Energized
Components
Alarms
Check for harvest problem (stuck HGV or relay),
hot water entering unit, stuck HM, or shorted thermistor.
Check thermistor (open), HGV not opening, TXV or LLV
leaking by, low charge, inefficient Comp, or WRV leaking
by.
Check FS stuck closed (up), WV leaking by, HGV leaking
by, PM not pumping, TXV defective, LLV not opening, low
charge, HM not bypassing, or inefficient Comp.
Red LED turns off if voltage protection operates.
Control voltage safeties automatically reset when voltage
is corrected.
55
Time LEDs are On
Min. Max.
1 minute 20 minutes
0 seconds 50 seconds
5 minutes freeze timer
setting
PM off 10 sec. when
thermistor at 36°F (2°C)
10 seconds 20 seconds
Notes