Scotsman FDE474 - Manual (Page 12)

Electrical Sequence
There are 7 indicator lights on the control board:
· WTR-OK. Water OK. Normal = Glowing. Glows
when there is water in the reservoir.
· PWR-OK. Power OK. Normal = Glowing. Glows
when the control board has power and is
functional.
· Service. Normally Off.
· Freeze. Normally Glowing when making ice.
· Bin Full. Normally Off when making ice.
· LED1. Normally Glowing when making ice.
· LED3. Normally Glowing when making ice.
Connecting power to the machine does the
following:
· The PWR-OK light glows.
· If there is water in the reservoir the WTR-OK
light glows.
· After 10 seconds the Freeze, LED1 and LED3
lights glow and the machine starts up.
Start Up:
· The compressor relay and auger motor relay
become energized, connecting power to the
windings of the auger motor and contactor coil.
· The contactor is energized, connecting power to
the compressor, and the compressor starts.
· During normal operation ice passes between
the ice level sensors but only interrupts their
infrared beam momentarily. The bin full light
remains off and the machine stays on until ice
builds up in the bin and blocks the path between
the sensors for 6 seconds or longer. When that
occurs the bin full light glows and the machine
shuts down.
Ice Vending
When the glass filler lever is pushed in the vend
switch closes, connecting power to the vend drive
motor.
Shut Down:
· The board’s compressor relay opens, LED1
goes out.
· The external compressor relay opens
· The compressor stops
· The auger motor stays on for 1 more minute,
clearing out ice in the evaporator, and then
· The auger motor relay opens, LED3 goes out
and the auger motor stops.
The compressor will not restart until 2 minutes or
more have passed after the last shut down.
If the path between the ice level sensors remains
clear for more than 10 seconds the ice machine
will restart.
Another purpose of the control board is to turn the
machine off when necessary:
· When the water level in the reservoir falls below
the water level sensor’s tip, the WTR-OK light
goes out and the machine shuts down. When
water refills the reservoir the WTR-OK light
glows and the machine starts up again.
· If the auger drive motor current becomes
excessive the compressor and auger drive
motor will be switched Off and the Service light
will blink. The control board will restart the auger
drive motor in 4 minutes. If during the first 60
seconds after restart the auger motor current
stays within limits, the compressor is restarted
and the machine returns to normal operation. If
the current is excessive within 60 seconds after
the restart, the process will be repeated once
more. If after that try the current is still
excessive the machine shuts down and must be
manually reset. The service light will then be
glowing continuously.
To Reset: Disconnect and reconnect electrical
power
FDE474
March 2000
Page 12