TM_i-BX(-N)_NC05_00_06_20_EN
MEHITS S.p.A.
●
TECHNICAL MANUAL
Version NC05 - Translation of the Original Instructions
40
4.8
ELECTRONIC EXPANSION VALVE
The electronic expansion valve is driven based on the PID algorithm, the proportional, integral and derivative values of which are set using the
parameter.
4.8.1
VALVE PRE-OPENING
Using parameter
136T
it is possible to set the type of valve pre-opening before the start of the compressor.
With
136T
= YES, valve pre-opening is equal to the number of steps defined by parameter
1360
(no relation with the requested capacity).
136K
defines the pre-opening time.
Other parameters:
1386
pre-opening in chiller
136U
pre-opening in heat pump
With
136T
= NO valve pre-opening is based on the requested capacity.
On i-BX-N units always set 136T = YES
4.8.2
EQUALIZATIONS AT START-UP
Parameter
131K
is used to set the type of valve pre-opening before the start of the compressor in compressor startup conditions with pressure
difference defined by parameter
1358
not being met.
With
131K
= YES, the valve pre-opening is equal to the number of steps defined by parameter
131Q
(no relation with the requested capacity).
On i-BX-N units always set 131K = YES
Other parameters:
1359
maximum equalization time
4.8.3
PRESSURE EQUALIZATIONS AT COMPRESSOR SHUTDOWN
In order to guarantee pressure equalization, at compressor shutdown the valve will open to the set number of steps (equal to parameter
1362
“Steps
valve open eq.”), a
nd will maintain this opening level for the time set in parameter
1361
(“time equalization EEV”). At the lapsing of this time, the valve
will switch to the set stand-by position.
Also this function is managed by parameter
131K
= YES.
On i-BX-N units always set 131K = YES
For the default values of the various parameters, see the parameters table