Service; Compressor Interlock; Manual Alternation; Relay On Time - Danfoss VLT CDS 303 Operating Instructions Manual

Parameter Descriptions

25-85 Relay ON Time

Array [2]
0 [0 – Readout of the value for Relay ON time. The
h 2147483647 Cascade Controller has set counters for the
*
h] compressors and for the relays that control
the compressors. Compressor cycling is always
done based on the relay counters, otherwise
it would always use the new compressor if a
compressor is replaced and its value in
parameter 25-84 Pump ON Time counter is
reset. In order to use parameter 25-04 Pump
Cycling, the Cascade Controller is monitoring
the Relay ON time.
25-86 Reset Relay Counters
Option: Function:
[0] Do not reset
*
[1] Do reset Resets all elements in parameter 25-85 Relay
ON Time.

6.14.6 25-9* Service

Parameters used in case of service on one or more of the
compressors controlled.

25-90 Compressor Interlock

Array [2]
In this parameter, it is possible to disable one or more
of the fixed lead compressors. For example, the
compressor will not be selected for staging on even if it
is the next compressor in the operation sequence. It is
not possible to disable the lead compressor with the
Compressor Interlock command.
The digital input interlocks are selected as [130 – 132]
Compressor 1-3 Interlock in parameter group 5-1* Digital
Inputs.
[0] Off The compressor is active for staging/destaging.
*
[1] On The Compressor Interlock command is given. If a
compressor is running it is immediately destaged. If the
compressor is not running it is not allowed to stage on.

25-91 Manual Alternation

Option: Function:
[0] 0 = Off - This parameter is only active if the options
Number of At Command or At Stating or Command are
*
Compressors selected in parameter 25-50 Lead Compressor
Alternation.
The parameter is for manually setting of
what compressor to be assigned as variable
speed compressor. The default value of
Manual Alternation is [0] Off. If a value other
MG34M422
Operating Instructions
25-91 Manual Alternation
Option:
Danfoss A/S © Rev. 2013-07-03 All rights reserved.
Function:
than [0] Off is set, the alternation is carried
out immediately and the compressor that is
selected with Manual Alternation is the new
variable speed compressor. After the
alternation has been carried out, the Manual
Alternation parameter is reset to [0] Off. If
the parameter is set to the number which
equals the actual variable speed
compressor, the parameter will be reset to
[0] immediately after.
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