12-21
CONTROL SYSTEM
SM DLSDCI 3-A.1 GB
12.5.2.9 Compressor taget frequency
During normal operation (excluding protections) the compressor target frequency is set according to
the ODU NLOAD number received from the indoor unit
.
ODU NLOAD
Target Frequency [Hz]
0
0
0
< ODU NLOAD ≤ MinFreq
MinFreq
>MinFreq
Linear relation between Min and Max freq.
12.5.3
EEV Control
12.5.3.1 EEV General Rules
The EEV is controlled to keep the optimal system performance at all times. It is done by means of discharge
superheat temperature and optimum compressor temperature control.
The target EEV value is the sum of open loop value (OL) and a result of the accumulative correction values (CV).
EEVi = EEVOLi
+ ∑EEVCV
i
12.5.3.2 EEV initialization procedure
After power up, the EEVs perform initialization procedure while it closed completely and reopened to predefined
position.
12.5.3.3 Balance time
During the first 5 minutes after SB the correction is not calculated. After that the correction value is updated every
EEVCVTConst seconds.
12.5.3.4 Operation Range
The EEV operation range is defined according to the operation mode as following:
Comp Status
ODU Mode
EEV
On
COOL
From
EEVMinOperOpenC
to
EEVMaxOperOpenC
On
HEAT
From
EEVMinOperOpenC
to
EEVMaxOperOpenC
On/Off
De-ice
EEVDeiceOpenSingle
OFF
Cool/Heat/Idle
400
12.5.3.5 EEV initial value determination (EEVOL
i
)
The EEV initial value (open loop) is determined according to the operation mode, the actual compressor speed
and indoor/outdoor conditions.
