Danfoss VLT AQUA Drive FC 202 Programming Manual page 210

Parameter Description
3.22.1 25-0* System Settings
Parameters related to control principles and configuration
of the system.
25-00 Cascade Controller
3 3
Option:
[0] Disabled
[1] Basic
Cascade Ctrl
[2] Motor
Alternation
Only
25-02 Motor Start
Option:
[0] Direct
on Line
*
[1] Soft
Starter
[2] Star
Delta
25-04 Pump Cycling
Option:
208
Function:
For operation of multiple devices (pump/fan)
systems where capacity is adapted to actual
load with speed control combined with on/off
control of the devices. For simplicity, only
pump systems are described.
To enable the cascade controller functionality,
set parameter 1-00 Configuration Mode to
option [3] Closed Loop.
The cascade controller is not active. All built-in
relays assigned to pump motors in the cascade
function are de-energized. If a variable speed
pump is connected to the frequency converter
directly (not controlled by a built-in relay), this
pump/fan is controlled as a single-pump
system.
The cascade controller is active and stages/
destages pump according to load on the
system.
Function:
Motors are connected to mains directly with a
contactor or with a soft starter. When the value of
parameter 25-02 Motor Start is set to an option
other than [0] Direct on Line, then
parameter 25-50 Lead Pump Alternation is automat-
ically set to the default of [0] Direct on Line.
Each fixed speed pump is connected to mains
directly via a contactor.
Each fixed speed pump is connected to mains via
a soft starter.
Fixed pumps connected with star-delta starters
are staged in the same way as pumps connected
with soft starters. They are destaged in the same
way as pumps connected directly to mains.
Function:
To provide equal hours of operation with fixed
speed pumps, the pump used can be cycled. The
selection of pump cycling is either first in – last out
or equal running hours for each pump.
Danfoss A/S © 05/2018 All rights reserved.
®
VLT AQUA Drive FC 202
25-04 Pump Cycling
Option:
[0] Disabled The fixed speed pumps are connected in the order
[1] Enabled The fixed speed pumps are connected/discon-
25-05 Fixed Lead Pump
Option: Function:
[0] No
[1] Yes The lead pump is fixed (no alternation) and connected
25-06 Number of Pumps
Range:
2 [ 2 -
*
9 ]
Function:
1–2 and disconnected in the order 2–1 (first in–last
out).
nected to have equal running hours for each
pump.
Fixed lead pump is a configuration when the variable
speed pump is connected directly to the frequency
converter. If a contactor is applied between frequency
converter and pump, this contactor is not controlled by
the frequency converter.
If operating with parameter 25-50 Lead Pump Alternation
set to other than [0] Off, set this parameter to [0] No.
The lead pump function can alternate between the
pumps controlled by the 2 built-in relays. Connect 1
pump to the built-in relay 1, and the other pump to
relay 2. The pump function (cascade pump1 and
cascade pump2) is automatically assigned to the relays
(maximum 2 pumps can in this case be controlled by
the frequency converter).
directly to the frequency converter.
Parameter 25-50 Lead Pump Alternation is automatically
set to [0] Off. Built-in relays, relay 1 and relay 2, can be
assigned to separate fixed speed pumps. In total, the
frequency converter can control 3 pumps.
Function:
The number of pumps connected to the cascade
controller including the variable speed pump. If the
variable speed pump is connected directly to the
frequency converter, and the other fixed speed
pumps (lag pumps) are controlled by the 2 built-in
relays, 3 pumps can be controlled. If both the
variable speed and fixed speed pumps are to be
controlled by built-in relays, only 2 pumps can be
connected.
If parameter 25-05 Fixed Lead Pump is set to [0] No: 1
variable speed pump and 1 fixed speed pump, both
controlled by built-in relay. If parameter 25-05 Fixed
Lead Pump is set to [1] Yes: 1 variable speed pump
and 1 fixed speed pump controlled by built-in
relays.
1 lead pump, see parameter 25-05 Fixed Lead Pump.
2 fixed speed pumps controlled by built-in relays.
MG20OB02