Flooded Type Water Cooled Screw Chiller Technical M
anual
51
2.2
Loading/Unloading Process Control of Unit
When shutdown time of compressor exceeds set time of 300S and return temperature of
cold water exceeds set value plus 1
℃
, compressor starts. When starting, it automatically
selects and makes head with the shortest time start firstly.
Unit operates by loading when return temperature of cold water is in loading area and
speedup loading area.
Unit unloads when return temperature of cold water is in unloading area. All compressors
stop operation if return temperature of cold water reaches emergency shutdown area.
Time interval of previous ON/OFF and next ON/OFF of each heads is at least five
minutes.
2.3 Protection Function
Flow Protection of Chilled Water Pump
Prerequisites for flow protection of refrigeration water pump:
①
After refrigeration water pump operates for 30S in case of set operation or power-on initial
startup;
②
ON/OFF state reflected by flow of refrigeration water pump is OFF state;
Emergency
Shutdown Area
Unloading Area
Stability Area
Stability Area
loading Area
Speedup Loading
Area
T
set
=12
