Service manual

13-6
CONTROL SYSTEM
SM DLF 1-A.1 GB
13.1.9 EEV (Electronic Expansion Valve) Control
13.1.9.1 EEV Control for DCI25/35/50/60
EEV opening is defined as EEV = EEV
OL
+ EEV
CV
EEV
OL
is the initial EEV opening as a function of the compressor frequency, operation mode, unit
model and capacity.
EEV
CV
is a correction value for the EEV opening that is based on the compressor temperature.
During the first 5 minutes of compressor operation EEV
CV
= 0.
Once the first 5 minutes are over, the correction value is calculated as follow: EEV
CV
(n) = EEV
CV
(n-1)
+ EEV
CTT
EEV
CTT
is the correction based on the compressor temperature. A target compressor temperatureзs
set depending on frequency and outdoor air temperature, and the actual compressor temperature is
compared to the target temperature to set the required correction to the EEVopening.
13.1.9.2 EEV Control for DCI72Z
The target EEV value is the sum of open loop value (OL) and a result of the accumulative correction
values (CV).


CVOL
EEVEEVEEV
Initial EEV value is set according to compressor frequency and according to indoor and outdoor
model
The corrective value is calculate every 30 sec the EEV corrective value is set to keep the discharged
super heat temperature between 20º to 30º in cooling and 12º to 20º in heating.
CONTENT