3.23.1 25-0* System Settings
Parameters related to control principles and conguration
of the system.
25-00 Cascade Controller
Option: Function:
For operation of multiple devices (pump/fan)
systems where capacity is adapted to actual load
with speed control combined with on/o control
of the devices. For simplicity, only pump systems
are described.
[0] * Disabled The cascade controller is not active. All built-in
relays assigned to pump motors in the cascade
function are de-energised. 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.
[1] Enabled The cascade controller is active and stages/
destages pump according to load on the system.
25-02 Motor Start
Option: Function:
Motors are connected to the 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.
[0]
*
Direct
on Line
Each xed speed pump is connected to mains
directly via a contactor.
[1] Soft
Starter
Each xed speed pump is connected to mains via
a soft starter.
[2] Star-
Delta
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.
25-04 Pump Cycling
Option: Function:
To provide equal hours of operation with xed
speed pumps, the pump use can be cycled. The
selection of pump cycling is either “rst in – last
out” or equal running hours for each pump.
[0] * Disabled The xed speed pumps are connected in the
order 1–2 and disconnected in the order 2–1 (rst
in–last out).
[1] Enabled The xed speed pumps are connected/discon-
nected to have equal running hours for each
pump.
25-05 Fixed Lead Pump
Option: Function:
Fixed lead pump means that the variable speed pump
is connected directly to the frequency converter, and 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]
O, set this parameter
to [0] No.
[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).
[1]
*
Yes The lead pump is xed (no alternation) and connected
directly to the frequency converter. The
parameter 25-50 Lead Pump Alternation is automatically
set to [0] O. Built-in relays RELAY 1 and RELAY 2 can
be assigned to separate xed speed pumps. In total, 3
pumps can be controlled by the frequency converter.
25-06 Number of Pumps
Range: Function:
2* [ 2 -
3 ]
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 xed speed
pumps (lag pumps) are controlled by the 2 built-in
relays, 3 pumps can be controlled. If both the
variable speed and xed 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 xed 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
xed speed pump controlled by built-in
relays.
1 lead pump, see parameter 25-05 Fixed Lead Pump.
2 xed speed pumps controlled by built-in relays.
3.23.2
25-2* Bandwidth Settings
Parameters for setting the bandwidth within which the
pressure is allowed to operate before staging/destaging
xed speed pumps. Also includes various timers to stabilise
the control.
Parameter Descriptions
Programming Guide
MG11CE02 Danfoss A/S © 03/2015 All rights reserved. 191
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