25-56 Staging Mode at Alternation
Option:
Function:
This parameter is only active if the option selected
in
parameter 25-50 Lead Pump Alternation
is different
from
[0] Off
.
2 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 (coasted).
[0]
*
Slow At alternation, the variable speed pump is ramped
up to maximum speed and then ramped down to a
stand still.
[1]
Quick At alternation, the variable speed pump is ramped
up to maximum speed and then coasted to stand
still.
is an example of the slow transfer-staging.
The variable speed pump (top graph) and 1 fixed speed
pump (bottom graph) run before the staging command.
When the
[0] Slow
transfer command is activated, an
alternation is carried out by ramping the variable speed
pump to
parameter 4-13 Motor Speed High Limit [RPM]
or
parameter 4-14 Motor Speed High Limit [Hz]
, and then
decelerated to zero speed. After a delay before starting
next pump (
parameter 25-58 Run Next Pump Delay
), the
next lead pump (middle graph) is accelerated and another
original lead pump (top graph) is added after the delay
before running on mains (
) as a fixed speed pump. The next lead pump (middle
graph) is decelerated to motor speed low limit and then
allowed to vary speed to maintain system pressure.
130BA369.10
Seconds
Variable speed
pump
Motor speed
high limit
Destaging
speed
Motor speed
low limit
Fixed speed
pump
Motor speed
low limit
Staging
speed
Motor speed
high limit
Seconds
Fixed speed
pump
Motor speed
high limit
Destaging
speed
Motor speed
low limit
Seconds
Delay before
running
on mains
Variable speed
pump
Delay
before starting
next pump
Staging
command
Illustration 3.81 Staging Mode at Alternation
25-58 Run Next Pump Delay
Range:
Function:
0.1 s
*
[0.1 -
5 s]
This parameter is only active if the option
selected in
parameter 25-50 Lead Pump Alternation
is different from
[0] Off
.
This parameter sets the time between stopping
the old variable speed pump and starting
another pump as a new variable speed pump.
Refer to
parameter 25-56 Staging Mode at
,
for description of
staging and alternation.
25-59 Run on Mains Delay
Range:
Function:
0.5 s
*
[ par.
25-58 - 5
s]
This parameter is only active if the option
selected in
, is different from
[0] Off
.
This parameter sets the time between
stopping the old variable speed pump and
starting this pump as a new fixed speed
pump. Refer to
for description
of staging and alternation.
3.23.5 25-8* Status
Readout parameters informing about the operating status
of the cascade controller and the pumps controlled.
25-80 Cascade Status
Range:
Function:
0
*
[0 - 25 ] Readout of the status of the cascade controller.
25-81 Pump Status
Range:
Function:
0
*
[0 -
25 ]
Pump status shows the status for the number of
pumps selected in
parameter 25-06 Number of Pumps
.
It is a readout of the status for each of the pumps
showing a string, which consists of pump number
and the current status of the pump.
Example: Readout is with the abbreviation like “1:D
2:O” This means that pump 1 is running and speed
controlled by the frequency converter and pump 2 is
stopped.
25-82 Lead Pump
Range:
Function:
0
*
[ 0 - par.
25-06 ]
Readout parameter for the actual variable speed
pump in the system. The lead pump parameter is
updated to reflect the current variable speed
pump in the system when an alternation takes
place. If no lead pump is selected (cascade
controller disabled or all pumps interlocked), the
display shows N1.
Parameter Descriptions
VLT
®
HVAC Drive FC 102
198
Danfoss A/S © 03/2015 All rights reserved.
MG11CE02
3
3
Содержание VLT HVAC Drive FC 102
Страница 1: ...Programming Guide VLT HVAC Drive FC 102 vlt drives danfoss com...
Страница 2: ......