Advanced Control Status - Carel EVD evolution User Manual

ENG
ON
A
OFF
ON
S
OFF
ON
P
OFF
ON
R
OFF
T1
Key:
A Control request
S Standby
P Pre-positioning
R Control
Positioning (change cooling capacity)
This control status is only valid for the pLAN driver.
If there is a change in unit cooling capacity of at least 10%, sent from the
pCO via the pLAN, the valve is positioned proportionally. In practice, this
involves repositioning starting from the current position in proportion to
how much the cooling capacity of the unit has increased or decreased
in percentage terms. When the calculated position has been reached,
regardless of the time taken (this varies according to the type of valve
and the position), there is a constant 5 second delay before the actual
control phase starts.
Note: if information is not available on the variation in unit cooling
capacity, this will always be considered as operating at 100% and therefore
the procedure will never be used. In this case, the PID control must be
more reactive (see the chapter on Control) so as to react promptly to
variations in load that are not communicated to the driver.
ON
A
OFF
ON
C
OFF
ON
NP
OFF
ON
R
OFF
T3
Key:
A Control request
C Change capacity
NP Repositioning
R Control
Stop/end control
The stop procedure involves closing the valve from the current position
until reaching 0 steps, plus a further number of steps so as to guarantee
complete closing. Following the stop phase, the valve returns to standby.
"EVD evolution" +0300005EN - rel. 3.1 - 25.07.2011
t
t
t
t
W T2
Fig. 6.b
W Wait
T1 Pre-positioning time
T2 Start-up delay after defrost
t Time
t
t
t
t
W
Fig. 6.c
T3 Repositioning time
W Wait
t Time
ON
A
OFF
ON
S
OFF
ON
ST
OFF
ON
R
OFF
T4
Key:
A Control request
S Standby
ST Stop

6.5 Advanced control status

As well as normal control status, the driver can have 3 special types of status
related to specifi c functions:
•
manual positioning: this is used to interrupt control so as to move the
valve, setting the desired position;
•
recover physical valve position: recover physical valve steps when
fully opened or closed;
•
unblock valve: forced valve movement if the driver considers it to be
blocked.
Manual positioning
Manual positioning can be activated at any time during the standby or
control phase. Manual positioning, once enabled, is used to freely set
the position of the valve using the corresponding parameter.
Parameter/description
CONTROL
Enable manual valve position
Manual valve position
Control is placed on hold, all the system and control alarms are enabled,
however neither control nor the protectors can be activated. Manual
positioning thus has priority over any status/protection of the driver
Note:
•
the manual positioning status is NOT saved when restarting after a
power failure.
•
in for any reason the valve needs to be kept stationary after a power
failure, proceed as follows:
-
remove the valve stator;
-
in Manufacturer programming mode, under the confi guration
parameters, set the PID proportional gain= 0. The valve will remain
stopped at the initial opening position, set by corresponding
parameter.
30
t
t
t
t
Fig. 6.d
R Control
T4 Stop position time
t Time
Def. Min. Max. UOM
0 0 1 -
0 0 9999 step
Tab. 6.n