Airwell SX 12 DCI, Service Manual

Page: 54 / 86

CONTROL SYSTEM
SM YAZ318 1-A.1 GB
11-13
11.5.3.6 Balance time
During the first 5 minutes after SB, the correction is not calculated. After that, the correction
value is updated every
30
seconds.
11.5.3.7 EEV corrections
The corrections in cool mode will keep the compressor in the proper operation temperature and
will balance between the indoor units by controlling their super heat.
11.5.3.8 Accumulative correction value storage
For each combination of active IDUs, the accumulated EEV correction value (for each IDU) will
be stored in the memory. Default correction values after power up are zero.
11.5.4 Outdoor Fan Speed Control
The OFAN operation keeps the outdoor heat exchanger temperature within a predefined values by
increasing or reducing the OFAN speed. Whenever the OFAN speed is abnormal, the OMT and
OCT sensors need to be checked.
11.5.4.1 Behavior when there is a failure in OFAN
Whenever OFAN fault occurs, the compressor will be stopped immediately.
11.5.4.2 Protection Behavior
•
In cool mode the OFAN will operate according to CTT or HST protection level:
Protection level
Action
SR, D1 or D2 OFAN will go to the Max. speed
Stop-Compressor
Continue to operate for maximum 3 minutes at 500 rpm or until normal level is
achieved.
11.5.4.3 OFAN Force On condition
If HST is faulty, OFAN will continue to operate for 3 minutes at 500 rpm after COMP is OFF.
11.5.4.4 Night mode
Upon receiving night mode, the OFAN will be limited to max
NightRPM
speed only in Cool. It
will be back to its normal operation when receiving the mode is cleared.
11.5.5 RV State Setting
During heat mode (except during Deicing) RV is ON.
During cool/SB mode, RV is OFF.
RV status will be changed only if COMP is OFF for 3 minutes or more.
11.5.6 Base Heater Setting
Base heater should be ON when unit is in heating and according to the below graph.
If OAT is disconnected, Base heater will be ON when unit is in heating.