Danfoss VLT CDS302 Operating Instructions Manual page 116

Parameter Descriptions
25-81 Compressor Status
Option:
[X] Disabled
6 6
[O] Off
[D] Running on
Frequency
Converter
[R] Running on
Mains
25-82 Lead Compressor
Option: Function:
0 N/A Readout parameter for the actual variable speed
compressor in the system. It is updated to reflect the
current variable speed compressor in the system when
an alternation takes place. If no lead compressor is
selected (Cascade Controller disabled or all
compressors interlocked) the display will show NONE.
25-83 Relay Status
Array [2]
On
Off Read out of the status for each of the relays assigned to
control the compressors. Every element in the array
represents a relay. If a relay is activated, the corresponding
element is set to "On". If a relay is deactivated, the
corresponding element is set to "Off".
25-84 Compressor ON Time
Array [2]
0 [0 –
h 2147483647
*
h]
116
Operating Instructions VLT
Function:
Compressor Status shows the status for the
number of compressors selected in
25-06 Number of Pumps. It is a readout of the
status for each of the compressors showing a
string, which consists of compressor number
and the current status of the compressor.
Example: Readout is with the abbreviation like
"1:D 2:O" This means that compressor 1 is
running and speed controlled by the
frequency converter and compressor 2 is
stopped.
The compressor is interlocked either via
25-90 Pump Interlock, or signal on a digital
input programmed for Compressor (number
on compressor) Interlock in parameter group
5-1* Digital Inputs. Can only refer to fixed
speed compressors.
Stopped by the cascade controller (but not
interlocked).
Variable speed compressor, regardless if
connected directly or controlled via relay in
the frequency converter.
Running on mains. Fixed speed compressor
running.
Readout of the value for Compressor ON
Time. The Cascade Controller has sete
counters for the compressors and for the
relays that control the compressors.
Compressor ON Time monitors the
"operating hours" of each compressor. The
value of each Compressor ON Time counter
can be reset to 0 by writing in the
®
MG34M302 - VLT is a registered Danfoss trademark/Commercial Compressor
®
CDS302 and CDS303
parameter, e.g. if the compressor is replaced
in case of service.
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 25-84 Pump ON Time counter is
reset. In order to use 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 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 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