Hoshizaki F-300BAF Manuale Utente

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IV. Service Diagnosis
A. Diagnostic Procedure
This diagnostic procedure is a sequence check that allows you to diagnose the electrical 
system and components under normal operating conditions of 70°F or warmer air and 
50°F or warmer water temperatures. Before proceeding, check for correct installation, 
proper voltage per unit nameplate and adequate water supply. 
1)  Unplug the unit from the electrical outlet and access the control panel.
) Plug the unit back in. Make sure the flush switch is in the ICE position, then place the 
power switch in the ON position. 
3) Fill Cycle – The water valve energizes. The reservoir begins to fill and the lower float 
switch closes. Nothing occurs at this time. The reservoir continues to fill and the upper 
float switch closes, energizng the water control relay. When the water control relay 
energizes, the inlet water valve de-energizes and the low water safety circuit closes to 
the timer board. 
Diagnosis: Check that the water valve fills the reservoir. If not, check 
for clogged water filters, clogged water valve screen, power supply to the unit, power 
circuit to the water valve (power switch, high pressure switch, transformer, safety switch, 
safety relay contacts, fuse, bin control, flush switch, flush relay, flush relay contacts, 
float switch, water control relay contacts), and the coil on the water valve.
3)  Ice Purge Cycle – (short cycle protection) The gear motor and the gear motor protect 
relay energize, and the 60 second compressor short cycle protection timer starts. 
Diagnosis: Check that the gear motor starts. If not, check the low water safety circuit 
on terminals 3 and 4 on the timer board, check for 10 volts on the gear motor relay 
terminal 8 on the timer board, check the gear motor fuse, thermal protector, and gear 
motor windings. If the gear motor starts but the auger does not turn: check the gear 
motor coupling between the auger and the gear motor. If the compressor starts the 
same time the gear motor starts: Check the compressor relay on the timer board (the 
black relay on the timer board is the compressor relay).
4) Freeze Cycle – The compressor and fan motor energize, the gear motor, gear motor 
protect relay, flush switch relay, and the water control relay remain energized. Ice 
production begins 4 to 6 minutes after the compressor and fan motor start depending 
on ambient and water conditions. 
Diagnosis: Check that the compressor and fan 
motor are running. If not, check for 10 volts on the compressor relay terminal 4 on the 
timer board (the black relay on the timer board is the compressor relay), check for 10 
volts on the gear motor protect relay, check gear motor relay contacts 4 and 6, check 
voltage on the compressor terminals, check the internal overload (motor protector), the 
compressor capacitors, and voltage to the fan motor and fan capacitor.