Hoshizaki KMD-201AWA Service Manual page 18

f) 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 "2.
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
Drain
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
(184Vac ± 5% or less)
High Voltage
7
(294Vac ± 5% or more)
Legend: Comp–compressor; DV–drain valve; FMS–self-contained fan motor; FVW–fill
water valve; HGV–hot gas valve; HM–headmaster; HWV–harvest water valve;
WRV–water regulating valve; PM–pump motor; TXV–thermostatic expansion valve
Energized
LED
Components
8 HWV
WV, HGV,
5, 6, 8
Comp
5, 7 (and Comp, PM, FMS
9 at refill) (FWV at refill)
Comp, HGV,
5, 6, 4, 7
DV, PM
Type of Alarm
Time LEDs are On
Min. Max.
2 min. 20 min.
freeze timer
5 min.
setting
10 sec. 20 sec.
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.
15
Avg.
60 sec
3 to 5 min.
25 to 30 min.
factory default setting
Notes