3.19.2 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 (compressor) systems where capacity is adapted to actual load by
means of speed control combined with on/off control of the devices. For simplicity only compressor
systems are described.
[0] *
Disabled
The Cascade Controller is not active. All built-in relays assigned to compressor motors in the cascade
function will be de-energized. If a variable speed compressor is connected to the frequency con-
verter directly (not controlled by a built-in relay), this compressor will be controlled as a single
compressor system.
[1]
Enabled
The Cascade Controller is active and will stage/destage compressors according to load on the sys-
tem.
NB!
This parameter can only be
Enabled
[1], if parameter 28-00
Short Cycle Protection
is set to
Disabled
[0].
25-04 Compressor Cycling
Option:
Function:
To provide equal hours of operation with fixed speed compressors, the compressor use can be
cycled. The selection of compressor cycling is either “first in – last out” or equal running hours for
each compressor.
[0] *
Disabled
The fixed speed compressors will be connected in the order 1 – 2 – 3 and disconnected in the order
3 – 2 – 1. (First in – last out)
[1]
Enabled
The fixed speed compressors will be connected/disconnected to have equal running hours for each
compressor.
25-06 Number of Compressors
Option:
Function:
The number of compressors connected to the Cascade Controller including the variable speed com-
pressor. If the variable speed compressor is connected directly to the frequency converter and the
other fixed speed compressors (lag compressors) are controlled by the two built in relays, three
compressors can be controlled. If both the variable speed and fixed speed compressors are to be
controlled by built-in relays, only two compressors can be connected.
[0] *
2 compressors
If
Fixed Lead Compressor
, par. 25-05, is set to
No
[0]: one variable speed compressor and one fixed
speed compressor; both controlled by built in relay. If
Fixed Lead Compressor
, par. 25-05, is set to
Yes
[1]: one variable speed compressor and one fixed speed compressor controlled by built-in relay
[1]
3 compressors
3 Compressors
[1]: One lead compressor, see
Fixed Lead Compressor
, par. 25-05. Two fixed speed
compressors controlled by built-in relays.
3.19.3 25-2* Zone Settings
Parameters for setting the zones within which the pressure will be allowed to operate before staging/destaging fixed speed compressors. Also includes
various timers to stabilize control.
3 Parameter Description
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Drive Programming Guide
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