3.23.2 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 sys-
tems 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.
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/disconnected 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 con-
verter 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 (maxi-
mum 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.
VLT
®
HVAC Drive Programming Guide 3 Parameter Description
MG.11.C9.02 - VLT
®
is a registered Danfoss trademark
241
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