Delta 21UT024C24 Instruction Manual page 28

Floor Ceiling Air-Conditioning Unit
D1 [Red] D2 [Red]
OFF OFF
0.5s
Circulating OFF
Flash
0.5s
OFF Circulating
Flash
0.5s
Continuous
Circulating
Light
Flash
Continuous
OFF
Light
0.5s 0.5s
Circulating Circulating
Flash Flash
To stop test running, press the ON/OFF button.
For the operation method, refer to the operating manual and perform operation check.
Check that there are no abnormal sounds or vibration during the test running.
Trouble Case Origin of Trouble
No power (24V)
to demand control
board terminals R
Power problem
and C or demand
control board
Actuation of high High pressure
pressure switch
Actuation of low Low pressure
pressure switch
Air discharge
Exhaust over-
high-temperature
temperature
protection of
compressor
Malfunction of
exhaust Temp. temperature
Sensor
Unit operating
Normal operation normally or in
standby mode.
Table.12
1.Check control transformer power (24V).
2.If power is available to demand control
board and LED(s) do not light, replace
control board.
failure.
Abnormality is detected when the contact
of the high pressure switch opens for 3
sec. The system will be shut down. The
unit will report this fault. For the first two
switch faults within 30 minutes, the unit can be
recovered automatically. If over three
times, the unit cannot be recovered
automatically.
When the unit runs more than 4 minutes
or does not run, the low pressure switch
opens for more than3sec and the system
will be shut down..The unit will report
switch this fault. For the first two faults within
30 minutes, the unit can be recovered
automatically. If over three times, the unit
cannot be recovered automatically.
The exhaust temperature is higher than
125°C for more than 5s, the system
will be shut down. After stopping the
compressor for 3 mins, if the exhaust
temperature is lower than 90°C for more
than 5s, the compressor will re-start.
Protection
For the first two faults within 30 minutes,
the unit can be recovered automatically.
If over three times, the unit cannot be
recovered automatically.
If the exhaust temperature sensor is
detected of open circuit 5 seconds
successively after the compressor is
Exhaust
started for 3 minutes or short circuit 5
seconds successively at any time The
sensor
system will be shut down. After the fault is
eliminated, the system can automatically
resume to operation.
None required
24
Measure