F) Led Lights And Audible Alarm Safeties - Hoshizaki KM-1900SAH 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 beep occurs when the control switch is moved to the "OFF" 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,
2. For more information, see "II.B. Sequence of Operation."
Sequence Step
1 Minute Fill Cycle 4
Harvest Cycle
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.)
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
S4 dip switch 9 & 10
To 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; FMR–remote fan motors; FMS–self-contained fan motors;
F/S–float switch; HGV–hot gas valve; HM–headmaster (C.P.R.); LLV–liquid
line valve; PM–pump motor; 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, 4*, 3, and Comp, FMR,
2 WV*, HGV,
PM
Type of Alarm
(53°C)
Time LEDs are On
Min.
2 minutes 20 minutes 3 to 5 minutes
5 minutes freeze timer
setting
10 seconds 20 seconds *pump-out timer
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, inefficient Comp,
or WRV leaking by.
Yellow LED marked "F TIMER" lights up.
Check for F/S stuck closed (up), WV leaking
by, HGV leaking by, PM not pumping, TXV
not feeding properly, low charge, HM not
bypassing, or inefficient Comp.
Red LED will turn off if voltage protection
operates.
The control voltage safeties automatically reset
when voltage is corrected.
23
Max. Avg.
60 seconds
30 to 35 minutes
setting
Notes