175ZA671.11
(27-24) SBW destage delay
SBW
SBW
Setpoint
(27-20)
(27-20)
Illustration 5.5
27-23 Staging Delay
Range:
Function:
15
s
*
[0 -
3000 s]
Staging Delay is the time that the system
feedback must remain below the operating
range before a pump may be turned on. If the
system is operating with at least one variable
speed pump available,
27-20 Normal Operating
Range
is used. If there are no variable speed
pumps available,
27-22 Fixed Speed Only
Operating Range
is used.
27-24 Destaging Delay
Range:
Function:
15
s
*
[0 -
3000 s]
De-staging Delay is the time that the system
feedback must remain above the operating
range before a pump may be turned off. If the
system is operating with at least one variable
speed pump available, the Normal Operating
Range (
27-20 Normal Operating Range
) is used. If
there are no variable speed pumps available
27-22 Fixed Speed Only Operating Range
is used.
27-25 Override Hold Time
Range:
Function:
10
s
*
[0 -
300 s]
Override Hold Time is the minimum time that
must elapse after a stage or de-stage before a
stage or de-stage may take place due to the
system exceeding the Override Limit (parameter
27-21). The override hold time is designed to allow
the system to stabilize after a pump is turned on
or off. If this delay is not long enough, the
transients caused by turning a pump on or off
may cause the system to add or remove another
pump when it should not.
27-27 Min-Speed De-stage Delay
Range:
Function:
15
s
*
[0 -
300 s]
Min-Speed De-stage Delay is the time that the
lead pump must be running at minimum speed
while the system feedback is still inside the
normal operating band before a pump will be
turned off to save energy. Energy savings may be
27-27 Min-Speed De-stage Delay
Range:
Function:
realized by turning off a pump if the variable
speed pumps are operating at minimum speed
but the feedback is still in band. Under these
conditions, a pump may be turned off and the
system will still be able to maintain control. The
pumps that remain on will then be operating
more efficiently.
175ZA640.11
(4-12)
(27-27)
F
min
F VLT pump
De-stage
timer period
Pump
switch-off
Illustration 5.6
5.1.6 Staging Speed, 27-3*
Parameters for configuring Master/Follower control
response.
27-30 Auto Tune Staging Speeds
Option:
Function:
[0] Disabled
[1] Enabled When parameter 27-30 is
[1] Enabled
, parameters
27-31, 27-32, 27-33 and 27-34 will be kept up to
date with new automatically calculated values. If
27-31 Stage On Speed [RPM]
,
27-32 Stage On Speed
[Hz]
,
27-33 Stage Off Speed [RPM]
and
27-34 Stage
Off Speed [Hz]
are modified from the bus or LCP,
then the new values will be used but will continue
to be automatically tuned.
Values will be recalculated and the parameters
updated when staging occurs.
When enabled the stage on and off speeds will continually
be auto tuned during operation. The settings will be
optimized in order to ensure a high performance and low
energy consumption.
27-31 Stage On Speed [RPM]
Range:
Function:
Size
related
*
[ 0 - par.
4-13 RPM]
To be used if RPM is chosen.
If the lead pump is operating above
Stage On Speed for the time specified
Parameter Descriptions
VLT
®
AQUA Drive MCO 101/MCO 102
28
MI38C402 - VLT
®
is a registered Danfoss trademark
5
5
