Danfoss VLT FC 100 Series Programming Manual page 189

Parameter Description
3.23.1 25-0* System Settings
Parameters related to control principles and configuration
of the system.
3 3
25-00 Cascade Controller
Option:
[0] Disabled The Cascade Controller is not active. All built-in
*
[1] Enabled The cascade controller is active and will stage/
25-02 Motor Start
Option:
[0] Direct on
*
Line
[1] Soft Starter Each fixed speed pump is connected to line
[2] Star-Delta
25-04 Pump Cycling
Option:
[0] Disabled The fixed-speed pumps will be connected in the
*
[1] Enabled The fixed-speed pumps will be connected/discon-
3-162
VLT
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.
relays assigned to pump motors in the cascade
function will be de-energized. If a variable-speed
pump is connected to the Adjustable frequency
drive directly (not controlled by a built-in relay);
this pump/fan will be controlled as a single pump
system.
destage pumps according to load on the system.
Function:
Motors are directly connected to the line
power with a contactor or a soft starter. When
the value of 25-02 Motor Start is set to an
option other than Direct on Line [0], then
25-50 Lead Pump Alternation is automatically
set to the default of Direct on Line [0].
Each fixed speed pump is directly connected
to line via a contactor.
via a soft starter.
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.
order 1 – 2 and disconnected in the order 2 – 1.
(First in – last out).
nected to have equal running hours for each
pump.
MG11CD22 - VLT
®
HVAC Drive Programming Guide
25-05 Fixed Lead Pump
Option:
Fixed Lead Pump means that the variable-speed pump
is connected directly to the Adjustable frequency drive
and if a contactor is applied between Adjustable
frequency drive and pump, this contactor will not be
controlled by the Adjustable frequency drive.
If operating with 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 automat-
ically be assigned to the relays (maximum two pumps
can in this case be controlled from the Adjustable
frequency drive).
[1] Yes The lead pump will be fixed (no alternation) and
*
connected directly to the Adjustable frequency drive.
The 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 Adjustable frequency
drive.
25-06 Number Of Pumps
Range:
2 [ 2 -
*
9. ]
3.23.2 25-2* Bandwidth Settings
Parameters for setting the bandwidth within which the
pressure will be allowed to operate before staging/de-
staging fixed-speed pumps. Also includes various timers to
stabilize the control.
® is a registered Danfoss trademark
Function:
Function:
The number of pumps connected to the Cascade
Controller including the variable speed pump. If the
variable-speed pump is connected directly to the
Adjustable frequency drive 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 25-05 Fixed Lead Pump, is set to No [0]: one
variable-speed pump and one fixed-speed pump;
both controlled by built-in relay. If 25-05 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 25-05 Fixed Lead Pump. Two
fixed-speed pumps controlled by built-in relays.