Danfoss VLT FC 100 Series Programming Manual page 218

3. Parameter Description
25-51 Alternation Event
Option:
* External
[0]
3
[1] Alternation Time Inter-
val
[2] Sleep Mode
[3] Predefined Time
25-52 Alternation Time Interval
Range:
*
24 h [1 – 999 h]
25-53 Alternation Time Value
Option:
0 N/A
25-54 Alternation Predefined Time
Range:
*
00:00 [00:00 – 23:59]
25-55 Alternation if Capacity < 50%
Option:
[0] Disabled
* Enabled
[1]
NB!
Only valid if
218
Function:
This parameter is only active if the options
par. 25-50, Lead Pump Alternation
in
place every time the event occurs.
Alternation takes place when a signal is applied to one of the digital inputs on the terminal strip and this input
Lead Pump Alternation
has been assigned to
Alternation takes place every time
Alternation takes place each time the lead pump goes into sleep mode.
set to Sleep Mode [1] or an external signal applied for this function.
Alternation takes place at a defined time of the day. If
alternation is carried out every day at the specified time. Default time is midnight (00:00 or 12:00AM depending
on the time format).
Function:
If Alternation Time Interval
speed pump takes place every time the Alternation Time Interval expires (can be checked out in
Value
, par. 25-53).
Function:
Readout parameter for the Alternation Time Interval value set in par. 25-52.
Function:
If option Predefined Time [3] in
carried out every day at the specified time set in Alternation Predefined Time. Default time is midnight (00:00 or
12:00AM depending on the time format).
Function:
If Alternation If Capacity <50% is enabled, the pump alternation can only occurs if the capacity is equal to or
below 50%. The capacity calculation is the ratio of running pumps (including the variable speed pump) to the
total number of available pumps (including variable speed pump, but not those interlocked).
N RUNNING
Capacity
=
N TOTAL
For the Basic Cascade Controller all pumps are equal size.
The lead pump alternation will take place at any pump capacity.
The lead pump function will be alternated only if the numbers of pumps running are providing less than 50%
of total pump capacity.
par. 25-50, Lead Pump Alternation
is different from
MG.11.C5.02 - VLT
VLT
At Command At Staging or Command
[2] or
. If an Alternation Event is selected, the alternation of lead pump takes
par. 5-1*, Digital Inputs
[121] in
par. 25-52, Alternation Time Interval
par. 25-54, Alternation Predefined Time
[1] option in Alternation Event , par. 25-51, is selected, the alternation of the variable
Alternation Event , par. 25-51, is selected, the variable speed pump alternation is
× 100 %
Off
[0].
® is a registered Danfoss trademark
®
HVAC Drive Programming Guide
[3] have been selected
.
, expires.
par. 20-23, No-Flow Function , must be
, is set, the
Alternation Timer