Service manual

11-4
CONTROL SYSTEM
SM HADDCI 1-A.2 GB
Notes:
When OAT is faulty or disabled OFAN will follow ‘Normal cases’ rules (left column).
1. The table above can be overruled during protections.
2. OFLowFreq = OFLowFreqC in cool mode, and OFLowFreqH in heat mode.
3. OFMedFreq = OFMedFreqC in cool mode, and OFMedFreqH in heat mode.
● The OFAN will be off when the compressor is off.
● An exception for the following rule is when compressor was operating in cool mode before
stopped. In this case OFAN will remain on in low speed for 1 minute.
● Whenever the indoor unit is under indoor coil overheating protection, as long as the
protection status is HzD2, the outdoor fan will change to off. It will be enabled to be
back on when the status of this protection becomes normal.
●Upon receiving night mode signal (ON), through communication, the OFAN will be
operating in LOW speed only in Cool. It will be back to its normal operation when
receiving OFF signal.
For S/W 370V and higher (For 467300225R Controller)
11.1.6.2 OFAN Operation in Cooling Mode
With keeping the OFAN general rules above in the highest priority, the operation of the OFAN will be operating
as the following:
OAT
Initial
Time After Compressor start up (minutes)
0 – 3min > 3min
OAT
Initial
>20
(or Faulty)
High(Relay)
OAT
Initial
≤20 Low(Triac)- Open Loop
Note:
The OAT
Initial
value represents one OAT reading exactly at the moment start up (actual freq>0).
Low (Triac)- By OMT represents the operation of the Low Fan speed controlled by Triac
according to OMT sensor.
CDT=max (OMT,OCT)
When in low (By CDT), the OFAN will reduce the speed
Whenever CDT is low, and
11.1.6 OFAN operation in heating mode
The outdoor fan will always be running at High speed during heating operation mode.
OFAN operation under Protections
The OFAN will switch to High Speed in the following cases:
1. Cooling mode AND
2. Compressor On (actual frequency>0).
HST, CTT, CDT, Current protections at HzDown1 or HzDown2 statuses
OAT (current)
High (Relay)
18 21
Low (Triac)- By CDT
Fir st Time enter s the
default is the last state
Note: OAT faulty , use High Speed
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