F) led lights and audible alarm safeties – Hoshizaki KM-901MWH User Manual
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f) LED Lights and Audible Alarm Safeties
(1) "E" Control Board: Auxiliary Code T-0, U-0
At startup, a 5-second delay occurs while the control board conducts an internal timer
check. A beep occurs when power is turned off. The red LED indicates proper control
voltage and remains on unless a control voltage problem occurs. The green LEDs
1 through 4 energize and sequence from initial startup as listed in the table below. Note
that the order of the LEDs from the outer edge of the control board is 1, 4, 3, 2.
For details, see "II.B. Sequence of Operation."
Sequence Step
LED
Energized
Components
Time LEDs are On
Min.
Max.
Avg.
1-Minute Fill Cycle 4
WV
1 minute
Harvest Cycle
1, 4, 2
Comp, FMR, WV,
HGV
2 minutes
20 minutes 3 to 5 minutes
Freeze Cycle
1
Comp, FM/FMR, PM,
LLV
5 minutes
freeze timer
setting
30 to 35 minutes
Pump-Out Cycle
1, 4*, 3, 2 Comp, FMR, WV*,
PM, HGV
10 seconds 20 seconds *pump-out timer setting
The built-in safeties shut down the unit and have alarms as listed below.
No. of Beeps
(every 3 sec.)
Type of Alarm
Notes
1
High Evaporator Temp.
(temperature > 127°F)
(53°C)
Check for harvest problem (stuck HGV or relay), hot
water entering unit, stuck HM, or shorted thermistor.
2
Harvest Backup Timer
(harvest > 20 min. for two cycles
in a row)
Orange "H TIMER" LED on.
Check for open thermistor, HGV not opening, TXV or
LLV leaking by, low charge, inefficient Comp, or WRV
leaking by.
3
Freeze Timer
(freeze > freeze timer setting for
two cycles in a row)
Yellow "F TIMER" LED on.
Check for F/S stuck closed (up), WV leaking by, HGV
leaking by, PM not pumping, TXV not feeding properly,
LLV not opening, low charge, HM not bypassing, or
inefficient Comp.
To reset the above safeties, press the "ALARM RESET" button with the power supply on.
6
Low Voltage
(92Vac±5% or less)
Red LED turns off if voltage protection operates.
The control voltage safeties automatically reset when
voltage is corrected.
7
High Voltage
(147Vac±5% or more)
Legend:
Comp–compressor; FM–fan motor; FMR–fan motor-remote;
F/S–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