Service Manual

18
2. LED Lights and Audible Alarm Safeties
At startup, a 5-second delay occurs while the control board conducts an internal timer
check.Abeepoccurswhenthecontrolswitchismovedtothe"ICE"position.
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 X10 Relay, WV 1 minute
Harvest Cycle 1, 4, 2 Comp, FMR, WV,
HGVs
2 minutes 20 minutes 3 to 5 minutes
Harvest Pump Timer 1, 3, 2 Comp, FMR, PM,
HGVs
0 seconds 50 seconds harvest pump timer
setting
Freeze Cycle 1 Comp, FMR, PM,
LLVs
5 minutes freeze timer
setting
30 to 35 minutes
Pump-Out Cycle 1, 3, 2 Comp, FMR, PM,
HGVs
10 seconds 20 seconds
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 HGVs), hot water
entering unit, stuck HM, or shorted thermistor.
2 Harvest Backup Timer
(harvest > 20 min. for two cycles
in a row)
Check for open thermistor, HGVs not opening, TXV or
LLVs leaking by, low charge, or inefficient Comp.
3 Freeze Timer
(freeze > freeze timer setting for
two cycles in a row)
Timer is factory set using S4 dip
switch 9 & 10
Check for F/S stuck closed (up), WV leaking by, HGVs
leaking by, PM not pumping, TXV not feeding properly,
LLVs 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; FMR–fan motor-remote; F/S–oat switch; HGVs–hot gas
valves (KMS and SRK); HM–headmaster (C.P.R.); LLVs–liquid line valves (KMS
and SRK); PM–pump motor; TXV–thermostatic expansion valve; WV–inlet water
valve;