6
Function description
RC.1J.Z4.02
©
Danfoss
09/1999
AKC 25H1
Neutral zone and regulating band
Neutral zone is set.
+zone and -zone bands are set.
Time delay in +zone and -zone band is set.
Time delay in ++zone and --zone band is set.
Compressor Capacity Ctrl.
Settings Compressor Ctrl.
NZ K
___
+Zone K
___
+Zone s
___
++Zone s
___
-Zone K
___
-Zone s
___
- -Zone s
___
Compressor definition
The controller can regulate up to nine compressor steps distributed on one, two or more
compressors. (If all nine steps are used for compressor control, there is no room left for the
control of condenser steps).
The controller is based on all the connected compressor steps being equally sized but this is
not a requirement.
The compressor steps must be defined in groups, so that the controller will know which steps
belong to compressor 1, which to compressor 2, etc. This definition is made by setting relay
outputs DO1 to DO9.
For each relay output you select the compressor that is to belong to it. If several are selected
with the same compressor number, it will be the relay with the lowest number that stops and
starts the compressor. The subsequent relays will control the individual unloaders.
Output Configuration
DO Relay No. ( )
DO( ) Type = 1(1=compressor)
DO( ) Dev. No
Example:
A system consists of two compressors. One with three steps and one with two steps. The
definition here is performed, as follows:
Output Configuration
DO Relay No. 1
DO1 Type = 1(1=compressor)*
DO1 Dev. No = 1
DO2 Type = 1(1=compressor)
DO2 Dev. No = 1
DO3 Type = 1(1=compressor)
DO3 Dev. No = 1
DO4 Type = 1(1=compressor)*
DO4 Dev. No = 2
DO5 Type = 1(1=compressor)
DO5 Dev. No = 2
The two relay outputs marked with a * will start and stop the compressors, and the others will
cut in and cut out the unloaders.
Time delays for cut ins and cut outs
To protect the compressor motor against frequent restarts, two time delays can be set.
- a minimum period which shall pass from a compressor starts till it can be restarted.
- a minimum period (on-time), during which the compressor must be operating, before it can be
stopped again (to avoid a cutout before the suction pressure has had time to become stable).
The setting ranges are from 0 to 25 minutes.
Output Configuration
DO Relay No. ( )
DO( ) Recy m ___
DO( ) ON m ___