Diagnostics - Remote Air Cooled - Scotsman Prodigy C0322 Technical & Service Manual

Diagnostics – Remote Air Cooled
No ice
Problem
No power to unit
No power to controller
Shut down on maximum
water fill time
Shut down on maximum
freeze time
Likely Cause
Power disconnected Check breaker or fuse.
Reset or replace, restart and check
Transformer open
Water shut off
Water leak
Dirty condenser
Restricted location, intake air too hot
Ice thickness sensor dirty or disconnected
Water distributor dirty
Inlet water valve leaks through during freeze
Connected to hot water
Incomplete harvest
High pressure cut out opened
Fan motor not turning
Water pump not pumping
Pump hose disconnected
Compressor not operating
Low refrigerant charge
Hot gas valve leaks through during freeze
Thermostatic expansion valve bulb loose
Thermostatic expansion valve producing very
low or very high superheat
Liquid line valve does not open
Compressor inefficient
Debris in refrigeration system
January 2015 Page 49
Probable Solution
Replace transformer
Restore water supply
Check purge valve, curtain, sump, pump
hose
Clean condenser
Have condenser moved
Check ice thickness sensor probe
Remove and clean water distributor
Check inlet water valve
Check for bleed thru from / missing check
valve in building water supply
Check harvest system
Check fan motor pressure control, check
fan motor, check controller using test
mode
Check fan motor, check fan blade
Check pump motor, check controller
using test mode
Check hose
Check compressor contactor, check
controller using test mode
Check compressor start components,
check PTCR resistance and temperature
Check compressor voltage
Check compressor windings
Add some refrigerant and restart unit. If
cycle time improves, look for leak.
Check hot gas valve for hot
outlet during freeze
Check bulb
Check evaporator superheat, change
TXV if incorrect
Check coil of valve, check controller
using test mode
Check compressor amp draw, if low and
all else is correct, change compressor
Recover charge. Open quick connects,
check for loose or missing foil. Open
liquid line and hot gas valves. Check for
debris. Replace drier, evacuate and
weigh in nameplate charge.