Danfoss VLT FC 100 Series Programming Manual page 219

®
VLT HVAC Drive Programming Guide
25-56 Staging Mode at Alternation
Option:
*
Slow
[0]
[1] Quick
The below figure is an example of the Slow transfer staging. The variable speed pump (top graph) and one fixed speed pump (bottom graph) are running
before the staging command. When the
par. 4-13, Motor Speed High Limit
Delay , ) the next lead pump (middle graph) is accelerated and another original lead pump (top graph) is added after the "Delay Before Running On
par. 25-60, Run on Mains Delay
Mains" (
allowed to vary speed to maintain system pressure.
25-58 Run Next Pump Delay
Range:
*
0.5 sec [Par.25-58 – 5.0 sec]
Function:
This parameter is only active if the option selected in
[0].
Two types of staging and destaging of pumps are possible. Slow transfer makes staging and destaging smooth.
Quick Transfer makes staging and destaging as fast as possible; the variable speed pump is just cut out (coas-
ted).
At alternation, the variable speed pump is ramped up to maximum speed and then ramped down to a stand
still.
At alternation, the variable speed pump is ramped up to maximum speed and then coasted to stand still.
Slow [0] transfer command is activated, an alternation is carried out by ramping the variable speed pump to
, or 4-14, and then decelerated to zero speed. After a "Delay Before Starting Next Pump" (
, ) as a fixed speed pump. The next lead pump (middle graph) is decelerated to Motor Speed Low Limit and then
Function:
This parameter is only active if the option selected in
[0].
This parameter sets the time between stopping the old variable speed pump and starting another pump as a
new variable speed pump. Refer to
staging and alternation.
MG.11.C5.02 - VLT ® is a registered Danfoss trademark
par. 25-50, Lead Pump Alternation
Lead Pump Alternation
Staging Mode at Alternation , par. 25-56, and Figure 7-5 for description of
3. Parameter Description
Off
, is different from
par. 25-59, Run Next Pump
Off
, par. 25-50, is different from
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