18
f) LED Lights and Audible Alarm Safeties
The control board includes LED indicator lights, audible alarm safeties, and an output
test. The red LED indicates 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 beep occurs when the control switch is moved to the "ICE" position.
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,
. For more information, see "II.B. Sequence of Operation."
Sequence Step
LED
Energized
Components
Time LEDs are On
Min.
Max.
Avg.
1 Minute Fill Cycle 4
FWV
60 seconds
Harvest Cycle
1, 4 and
Comp, FMR
HWV, HGV
minutes
0 minutes 3 to 5 minutes
Last 50 seconds of harvest, HWV de-energizes and PM energizes.
LEDs 1, 3 and are on.
Freeze Cycle
1 (and 4 at
refills)
Comp, FMR,
PM, LLV
(FWV at refill)
5 minutes
freeze timer
setting
30 to 35
minutes
Pump-Out Cycle
1, 4*, 3, and
Comp, FMR,
HWV*, PM,
HGV, DWV,
10 seconds 0 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 > 17°F)
(53°C)
Check for harvest problem (stuck HGV or
relay), hot water entering unit, stuck HM or
shorted thermistor.
Harvest Backup Timer
(harvest > 0 min. for two
cycles in a row)
Check for open thermistor, HGV not opening,
TXV leaking by, low charge or inefficient Comp.
3
Freeze Timer
(freeze > specified setting
for two cycles in a row)
Timer is factory set using
S4 dip switch 9 & 10
Check for a float switch stuck closed (up),
HWV or FWV leaking by, HGV leaking by,
PM not pumping, TXV not feeding properly,
low charge, HM not bypassing or inefficient
compressor.
To reset the above safeties, press the "ALARM RESET" button with the power supply on.
6
Low Voltage
(9Vac ±5% or less)
Red LED will turn 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;
DWV
–drain water valve;
FMR
–remote fan motor;
FWV
–fill
water valve;
HGV
–hot gas valve;
HM
–headmaster;
HWV
–harvest water valve;
LLV
–liquid line valve;
PM
–pump motor;
TXV
–thermostatic expansion valve