M&M
R
EFRIGERATION
I
NC
. 3-11
Chapter 3: Capacity Control
Remote Capacity Control
I/O Control
When remote operation is desired using discrete I/O signals, and the compressor is in
the Remote mode, capacity control is performed using the Remote Load and Remote
Unload inputs. The relationship of these signals to slide valve movement is shown in
the following table.
NOTE: Remote Capacity Control is only active while the screw compressor is running.
Network Control
When the Network Communications option is enabled, and the compressor is in the
Remote mode, capacity control is performed using load and unload messages from a
remote computer. For more information on network operation, please refer to Appen-
dix C.
Auto-Remote Capacity Control
I/O Control
When remote operation is desired using discrete I/O signals, and the compressor is in
the Auto-Remote mode, capacity control is performed using Automatic Capacity Con-
trol. Remote Setpoint signals A and B are used to select the current active setpoint
group to be used for automatic capacity control in the Auto-Remote mode. The input
settings for the different group numbers are shown in the following table.
The operator can enable and disable Remote setpoint selection from the Miscella-
neous Control screen under the MISC hot key.
NOTE: Scheduling should be disabled when the Remote setpoint selection feature is enabled.
REMOTE LOAD REMOTE UNLOAD SLIDE VALVE MOVEMENT
Low Low Holding
High Low Loading
Low High Unloading
High High (Should not be used)
GROUP
NUMBER
REMOTE SET-
POINT A
REMOTE SET-
POINT B
1LowLow
2HighLow
3LowHigh
4 High High
To Next Page
Loading...
Need help?
General