Led Lights And Audible Alarm Safeties - Hoshizaki KM-230BAJ Service Manual

B. LED Lights and Audible Alarm Safeties
The control board includes LED indicator lights, audible alarm safeties, and an output
test feature. The "POWER OK" LED indicates control voltage and will remain on unless
a control voltage problem occurs. The "POWER OK" LED flashes continuously when the
bin is full and DV energizes for a maximum of 5 minutes to drain the water tank.
At startup, a 5 second delay occurs to stabilize the circuit. LEDs 4 through 8 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 5, 6, 8, 9, 4, 7. For more information, see "II. A.
Sequence of Operation".
Sequence Step
1 Minute Fill Cycle
Harvest Cycle
Last 0, 10, 30, or 50 seconds (adjustable by dip switch) of harvest, WV de-energizes
and PM energizes (LEDs 5, 6, and 7 are on)
Freeze Cycle
Pump-Out Cycle
The built in safeties shut down the unit and have alarms as listed below.
No. of Beeps
(every 3 sec.)
High Evaporator Temp.
1 (temperature > 127°F (53°C))
Harvest Backup Timer
2 (harvest > 20 min. for two
cycles in a row)
Freeze Timer
(freeze > specified setting for
3 two cycles in a row)
Timer is factory set using S1
dip switch 9 & 10
To reset the above safeties, press the "ALARM RESET" button with the power supply
on.
Low Voltage
6
(92Vac ± 5% or less)
High Voltage
7
(147Vac ± 5% or more)
Legend: Comp–compressor; DV–drain valve; FMS–self-contained fan motor; HGV–hot
gas valve; PM–pump motor; TXV–thermostatic expansion valve; WRV–water
regulating valve; WV–inlet water valve
Energized
LED
Components
8 WV
WV, HGV,
5, 6, 8
Comp
Comp, PM,
5, 7
FMS
Comp, HGV,
5, 6, 4, 7
DV, PM
Type of Alarm
Time LEDs are On
Min.
2 minutes 20 minutes 3 to 5 minutes
freeze timer
5 minutes
setting
10 seconds 20 seconds
Check for harvest problem (stuck HGV or
relay), hot water entering unit, stuck HM, or
shorted thermistor.
Check for open thermistor, HGV not
opening, TXV leaking by, low charge,
inefficient Comp, or WRV leaking by.
Check for a float switch stuck closed (up),
WV leaking by, HGV leaking by, PM not
pumping, TXV not feeding properly, low
charge, or inefficient Comp.
"POWER OK" LED will turn off if voltage
protection operates.
The control voltage safeties automatically
reset when voltage is corrected.
32
Max. Avg.
60 seconds
25 to 30 minutes
factory default
setting
Notes