Operating instructions
3.23.1 25-0* System Settings
Parameters related to control principles and configuration of
the system.
25-00 Cascade Controller
Option: Function:
For operation of multiple devices (pump/fan)
systems where capacity is adapted to actual load
by means of speed control combined with on/off
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 will be de-energized. If a variable speed
pump is connected to the frequency converter
directly (not controlled by a built-in relay); this
pump/fan will be controlled as a single pump
system.
[1] Enabled The Cascade Controller is active and will stage/
destage pumps 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
par. 25-02 Motor Start is set to an option other
than Direct on Line [0], then par. 25-50 Lead Pump
Alternation is automatically set to the default of
Direct on Line [0].
[0]
*
Direct on
Line
Each fixed speed pump is connected to line
directly via a contactor.
[1] Soft
Starter
Each fixed speed pump is connected to line via a
soft starter.
[2] Star-Delta
25-04 Pump Cycling
Option: Function:
To provide equal hours of operation with fixed
speed pumps, the pump use can be cycled. The
selection of pump cycling is either “first in – last
out” or equal running hours for each pump.
[0]
*
Disabled The fixed speed pumps will be connected in the
order 1 – 2 and disconnected in the order 2 – 1.
(First in – last out).
[1] Enabled The fixed speed pumps will be 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 will not be controlled by the
frequency converter.
If operating with par. 25-50 Lead Pump Alternation set to
other than Off[0], this parameter must be set to No [0].
[0] No The lead pump function can alternate between the
pumps controlled by the two built in relays. One pump
must be connected to the built-in RELAY 1, and the
other pump to RELAY 2. The pump function (Cascade
Pump1 and Cascade Pump2) will automatically be
assigned to the relays (maximum two pumps can in this
case be controlled from the frequency converter).
[1]
*
Yes The lead pump will be fixed (no alternation) and
connected directly to the frequency converter. The
par. 25-50 Lead Pump Alternation is automatically set to
Off [0]. Built-in relays Relay 1 and Relay 2 can be
assigned to separate fixed speed pumps. In total three
pumps can be controlled by the frequency converter.
25-06 Number of Pumps
Range: Function:
2
*
[Applica-
tion
depend-
ant]
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 two built
in relays, three pumps can be controlled If both
the variable speed and fixed speed pumps are to
be controlled by built-in relays, only two pumps
can be connected.
If par. 25-05 Fixed Lead Pump, Fixed Lead Pump, is
set to No [0]: one variable speed pump and one
fixed speed pump; both controlled by built in
relay. If par. 25-05 Fixed Lead Pump, Fixed Lead
Pump, is set to Yes [1]: one variable speed pump
and one fixed speed pump controlled by built-in
relay.
One lead pump, see par. 25-05 Fixed Lead Pump.
Two fixed speed pumps controlled by built-in
relays.
Parameter Description
VLT
®
HVAC Drive Programming Guide
168 MG.11.CA.02 - VLT
®
is a registered Danfoss trademark
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