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OPERATION (CONT'D)TEST MODECOMMISSIONING
7. TEST MODE
Test mode can only be activated when both compressors are OFF.
To start test mode press and hold down the push button on the lower board between 1 and 5 seconds.
In test mode each output is activated for 5 to 10 seconds, one output at a time. When test mode completes the unit
automatically returns to normal operation.
Display indication during test mode - letter A
8. COMMISSIONING MODE
To start commissioning mode press and hold down the push button on the lower board between 10 and 15 seconds.
In commissioning mode all time delays are reduced to 1/10th their standard value to enable rapid diagnostic testing.
Commissioning mode automatically completes after 30 minutes and the unit will return to normal operation. Cycling
mains power off and on again also ends commissioning mode.
Display indication during commissioning mode - letter C
When indoor coil frost protection is activated the
compressor is stopped for 15 minutes, after which it is
allowed to restart.
If three consecutive trips occur then the unit will be
“locked out”. The trip counter is reset to 0 when there
has been no compressor run request for longer than 60
minutes.
Display indication when protection is active -
number 7 (ashing)
6.5 High discharge line temperature protection (HDT)
The controller monitors the discharge line temperature
(inputs DT1, DT2) and should it rise above 110°C the
compressor will be stopped.
When high temperature protection is activated the
compressor is stopped for at least 3 minutes. The
compressor is allowed to restart after 3 minutes
provided that the discharge line temperature has fallen
to below 100°C.
If three consecutive trips occur then the unit will be
“locked out”. The trip counter is reset to 0 when there
has been no compressor run request for longer than 60
minutes.
Units with a variable compressor or digital scroll
compressor will automatically reduce capacity before
the discharge temperature rises close to the threshold.
Display indication when protection is active -
number 9 (ashing)
6.6 Compressor lock-out
Certain faults (as outlined in the preceding paragraphs)
can cause the unit to be “locked out” if they occur
three consecutive times while the compressor-run
request has remained active. When a unit is locked out
the compressor is not allowed to start until the lock-
out is manually reset. Lock-out protects the unit from
repeatedly starting the compressor when a serious fault
exists that requires the attention of a service technician.
When a unit is locked out the alarm relay output (NO7,
NC7) will be active.
A unit that is locked out can be reset by either of the
following two methods:
1. Remove mains power from the unit for at least 3
seconds, then restore power.
2. Use a UC6 service tool service tool to manually reset
the lock-out condition.
Display indication when protection is active -
letter F (ashing)
6.7 Sensor alarm
If the signal of a temperature sensor or pressure
transducer is out of normal operating range the UC6
will generate an alarm. The sensor may be faulty,
disconnected or short circuit.
Display indication temperature sensor alarm -
number 5 (ashing)
Display indication pressure transducer alarm -
number 6 (ashing)
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