Danfoss VLT FC 102 Programming Manual page 238

Parameter Descriptions
3.23.1 25-0* System Settings
Parameters related to control principles and configuration
of the system.
25-00 Cascade Controller
3 3
Option:
[0] Disabled
*
[1] Enabled
25-02 Motor Start
Option:
[0] Direct on Line
*
[1] Soft Starter
[2] Star-Delta
236
®
VLT HVAC Drive FC 102
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 automatically
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.
Danfoss A/S © 10/2019 All rights reserved.
25-04 Pump Cycling
Option: 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.
[0] Disabled The fixed–speed pumps are
*
connected in the order 1–2 and
disconnected in the order 2–1 (first
in–last out).
[1] Enabled The fixed–speed pumps are
connected/disconnected to have
equal running hours for each pump.
25-05 Fixed Lead Pump
Option: Function:
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.
[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 fixed (no
*
alternation) and connected 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.
M0010001