F) Led Lights And Audible Alarm Safeties - Hoshizaki KML-451MAH Service Manual

f) LED Lights and Audible Alarm Safeties

The red LED indicates proper control voltage and will remain on unless a control voltage
problem occurs. At startup a 5 second delay occurs while the board conducts an internal
timer check. A short beep occurs when the power switch is turned OFF.
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 board is 1, 4, 3, 2.
For more information, see "II.B. Sequence of Operation."
Sequence Step
1 Minute Fill Cycle 4
Harvest Cycle
Freeze Cycle
Pump Out
The built in safeties shut down the unit and have alarms as follows:
No. of Beeps
(every 3 sec.)
1 High Evaporator Temp.
(temperature > 127°F)
2 Harvest Backup Timer
(harvest > 20 min. for two
cycles in a row)
3 Freeze Timer
(freeze > specified setting
for two cycles in a row)
Timer is factory set using
dip switches 9 & 10
To manually reset the above safeties, press the alarm reset button with the power
supply on.
6 Low Voltage
(92Vac ±5% or less)
7 High Voltage
(147Vac ±5% or more)
Legend: Comp–compressor; DV–Drain Valve; FMR–remote fan motor; FMS–self-
contained fan motor; F/S–float switch; HGV–hot gas valve; HM–headmaster
(C.P.R.); LLV–Liquid Line Valve; PM–pump motor; SR–Service Relay;
TXV–thermostatic expansion valve; WV–inlet water valve
Energized
LED
Components
WV
1, 4, and 2 WV, HGV,
Comp, FMR
1 Comp, PM,
FMR/FMS,
LLV
1, 3, and 2 Comp, HGV,
PM, FMR,
SR, DV
Type of Alarm
(53°C)
Time LEDs are On
Min. Max.
2 minutes 20 minutes 3 to 5 minutes
5 minutes freeze timer
setting
10 seconds 20 seconds factory setting
Notes
Check for harvest problem (stuck HGV or
relay), hot water entering unit, stuck HM,
or shorted thermistor.
Orange LED marked H TIMER lights up.
Check for open thermistor, HGV not
opening, TXV leaking by, low charge, or
inefficient compressor.
Yellow LED marked F TIMER lights up.
Check for F/S stuck closed (up), WV
leaking by, HGV leaking by, TXV not
feeding properly, low charge, HM not
bypassing, or inefficient compressor.
Red LED will turn off if voltage protection
operates.
The control voltage safeties automatically
reset when voltage is corrected.
14
Avg.
60 seconds
30 to 35 minutes