desmon GBC-15, Service Manual

Page: 10 / 100

Rev 07/04/2015
10
1.1. ALARM/FAILURE LIST
Tab 1
CODE CAUSE CONSEQUENCE
Er0 ROOM PROBE FAILURE Does not allow unit to cycle. If running,
cycle will stop.
Er1 EVAPORATOR PROBE FAILURE During storage cycle, evaporator fans
do not run.
Er3 NEEDLE PROBE FAILURE Does not allow a needle probe set
temperature cycle to run. Unit will stop
if running on needle probe set
temperature cycle.
HP HIGH DISCHARGE PRESSURE (OR
LOW SUCTION PRESSURE)
1
Unit will not operate in any cycle. If
running, compressor, evaporator and
condenser fans will stop.
d-r DOOR IS OPEN FOR MORE THAN
P39 Compressor and condenser fan will
stop.
Evaporator fan will cycle
according to P37
AH HIGHT ROOM TEMPERATURE None
AL LOW ROOM TEMPERATURE None
Err MOTHER BOARD-KEYBOARD
CONNECTION FAILURE
2
None
Res POWER FAILURE DURING
RUNNING OF CYCLE Cycle will restart when power is
restored. Message
will flash to
indicate cycle has restarted.
1
The pressure switch in this model series provides a single output, open or closed. The
circuit is normally open and will close when either the High or Low Pressure limits are
reached. In effect, the failure code, HP, could mean either high discharge pressure as well
as low suction pressure.
2
Additional troubleshooting at the Key Pad – Control Module connections:
No Ground connection – Display flashes and/or dims
No Negative (-) connection – Display may work normally without failure code
No Positive (+) connection – Failure Code Error is displayed
No 12V connection – Display will not light up.