Service manual

12-5
CONTROL SYSTEM
SM DNGDCI 2-E.1 GB
Compressor
Target Frequency
OFAN Speed
Routin
A
Routin
B
Routin
C
Routin
D
Freq=0 OFF OFF OFF OFF
10 = Freq < OFLowFreq Low Low VL Low
OFLowFreq = Freq< OFMedFreq Medium Low VL Low
OFMedFreq= Freq High Low Low Medium
OFAN
O A T
S
t
a
t
e
at C ool Mode
20
A
B
C
3 Degrees
3 Degrees
7
Note: Periorities A>B>C
Change To Higher
OFAN Cool state (*1)
45
50
HST
Change To lower
OFAN Cool state
(*1) If State C, change to B
If State B, change to A
When compressor is switched to OFF and the heat sink temperature is above 55 degrees, theoutdoor
fan will remain ON in low speed for up to 3 minutes.
12.1.7.2 Outdoor Fan Control for DCI72/80
OFAN operates between OFMinRPM to OFMaxRPM.
Min time for speed change of OFAN OFMinTimeReduce (60 seconds).
There are 4 defined speeds – High, Med, Low, and Very Low.
The fan speed is also related to protections and OMT value.
12.1.8 EEV (Electronic Expansion Valve) Control
12.1.8.1 EEV Control for DCI60
EEV opening is defined as EEV = EEV
OL + EEVCV.
EEVOL is the initial EEV opening as a function of the compressor frequency, operation mode, unitmodel
and capacity.
EEVCV is a correction value for the EEV opening that is based on the compressor temperature.
During the first 5 minutes of compressor operation EEVCV = 0.Once the first 5 minutes are over, the
correction value is calculated as follow: EEVCV(n) =EEVCV(n-1) + EEVCTT.
EEVCTT is the correction based on the compressor temperature. A target compressor temperatureis
set depending on frequency and outdoor air temperature, and the actual compressortemperature is
compared to the target temperature to set the required correction to the EEVopening.
CONTENT