Heatcraft Refrigeration Products 25001501 Installation & Operating Instructions Manual page 19

SERVICE DIAGNOSIS CHART - BEACON
PROBLEM
Compressor will not run
Cannot get to box temp
Superheat light indicates
1 deg then 8 deg
Freezer coil icing
Compressor Cycles off at
startup w/o pumping down
Unit Cycles on and off
without 4 min. time delay
BEACON CONTROLLER
POSSIBLE CAUSE
1. 4 min. off cycle
2. Box temp is below t'stat setting
3. Loose wiring
4. Bad sensor
5. Discharge temp. too high
6. Beacon board defective
7. Low pressure switch open
8. Supply voltage too low
9. Evap coil temp too high
1. Wrong t'stat setting
2. Wrong selection on board
3. Comp. run time too short
4. Bad expansion valve
5. Wrong charge
6. Box temp fluctuate
7. Evap coil iced up
8. Wrong nozzle
9. Low pressure switch
tripping compressor
1. Incorrect refrigerant charge
2. Expansion valve oversized
3. Superheat set too low
4. System not stabilized
5. Evap coil iced up
1. Insufficient refrigerant.
2. Wrong defrost termination setting
3. Wrong defrost fail-safe setting
4. Evap fan not running
5. Defrost heater not working
6. Faulty defrost termination sensor
7. Not enough defrost for
conditions or infiltration
8. Undersized system
1. Low pressure switch setting
too high
2. Low pressure switch
tripping compressor
3. Compressor out on thermal
overload protector
1. Incorrect wiring
2. Low pressure switch
tripping compressor
3. Time delay bad or
not set for 2 minutes
POSSIBLE CORRECTIVE ACTION
1. Wait 4 min.
2. Lower t'stat setting
3. Check all wire terminals; tighten if necessary.
4. Check status light for problem sensor
5. Check general diagnosis chart
6. Check "Status" light; if out, replace board
7. Check pressure switch setting.
8. Change transformer primary to correct supply
voltage tap. 208 or 240 volts.
9. Temporarily disconnect "Evap Coil" sensor from
board; reconnect when coil temp is lowered
1. Check and adjust t'stat
2. For box temp of 20 F and above, select
"MEDIUM"; for box temp below 20 F,
select "LOW"
3. a) Increase time between defrost. b) May need
time delay across low pressure switch. (See
"Compressor cycles off at startup" below.)
4. Check if expansion valve is operating
5. Check charging procedure
6. Allow system to run longer
7. Clear ice and check defrost setting
8. Check if distributor tubes are sweating evenly; if
not, have factory check nozzle selection for
application.
9. EXV closing down due to low superheat; check
"EVAP IN" & "EVAP OUT" sensors; check
refrigerant charge.
1. Check refrigerant charge
2. Check expansion valve size
3. Raise superheat setting
4. Allow system to run longer
5. Clear ice
1. Check system for leaks; repair leaks &
add refrigerant
2. Raise setting on the board
3. Raise setting on the board
4. Check fan circuit and board relay
5. Check heater circuit and board relay
6. Check sensor on evap coil
1. Change low pressure cutout to 0 PSIG
and 10 PSIG cut-in
2a.EXV closing down due to low superheat; check
"EVAP IN" & "EVAP OUT" sensors
2b.Check refrigerant charge.
2c.Check if sensors are connected to correct
terminals on Beacon board.
1a.Check wiring
1b.Bad Beacon board
2a.EXV closing down due to low superheat; check
"EVAP IN" & "EVAP OUT" sensors
2b.Check refrigerant charge.
2c.Check if sensors are connected to correct
terminals on Beacon board.
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