KGL Operating Manual – VS 3010 BS
2018-07-02
/
67 178
4.8.6 Low-pressure monitoring Z1/Z2
The low-pressure monitoring is performed separately for the Z1 and Z2 temperature range. If the low-pressure
falls to a configurable threshold (menu 3-3 to Comp. OFF Z1/Z2), all compressors are unloaded. If the low-
pressure rises to the proportional t0 se NZ/2 pressure value, the compressors are loaded stage by
stage as already described.
An alarm is signalled after expiry of a delay time. Delay time (menu 3-3 Del. To OFF) and alarm priority can be
configured. The threshold is input in °C. The controller calculates an absolute proportional pressure value from
this value. The LP cutout is also evaluated. If the pressure drops below the threshold of the LP cutout, a forced
shutdown of all compressors occurs.
4.8.7 Z1/Z2 minimum suction gas superheat monitoring
Introduction
The suction gas superheat in two circuits (Z1/Z2) is recorded and monitored separately in the pack controller.
The recording is performed using the following Pt1000 temperature sensors:
Z1: Pt1000 input 12, terminals 31/32
Z2: Pt1000 input 13, terminals 33/34
The suction gas superheat is the difference between the suction gas temperature and t0, and can only have
positive values.
Functionality
The suction gas superheat is monitored for undercutting of a configurable threshold. The alarm "Low
SuperHeat Zx" is output if the superheat remains below the threshold for a configurable time. The alarm
signalling has no effects on the control function of the pack controller.
Criteria for tripping the "Low SuperHeat Zx" message
Superheat remains below the
threshold for the delay time
Min. Superheat Zx
delay min SH Zx
At least one compressor in the respective circuit must be ON (the delay time is reset if no compressor is
