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
is set to an
option other than
Direct on Line
[0], then
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
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 automat-
ically 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
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
*
[ 2 -
9. ]
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
, is set to
No
[0]: one
variable speed pump and one fixed speed pump;
both controlled by built in relay. If
is set to
Yes
[1]: one variable speed pump and
one fixed speed pump controlled by built-in relay.
One lead pump, see
. Two
fixed speed pumps controlled by built-in relays.
3.23.2 25-2* Bandwidth Settings
Parameters for setting the bandwidth within which the
pressure will be allowed to operate before staging/
destaging fixed speed pumps. Also includes various timers
to stabilize the control.
Parameter Description
VLT
®
HVAC Drive Programming Guide
178
MG.11.CC.02 - VLT
®
is a registered Danfoss trademark
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