Flooded Type Water Cooled Screw Chiller Technical M
anual
29
Normal startup sequence of star-delta: switch on power supply; press startup key of unit;
three minutes later, main and star A/C contactor attract; after 2-5s, star A/C contactor
disconnects; angle A/C contactor attracts; unit begins to start at startup load and load
gradually.
Normal startup sequence of shunt winding: switch on power supply; press startup key of unit;
three minutes later, main contactor attract; after main contactor attracts for 0.5s, unit begins to
start at startup load and load gradually.
Before starting, check if external system of unit meets condition of startup (if refrigeration water
pump and cooling water pump of system are in mode of external control or main linkage; as
for external control, it’s necessary to firstly open water pump before starting main unit)
(enclosed with checklist)
Step 2: Check compressor and refrigeration pipeline
All refrigerant valves (angle valve at outlet of condenser, intake and discharge cut-off valve of
compressor, cut-off valve at connection of high & low pressure switch of compressor) in refrigeration
system should be opened to make refrigeration system smooth;
Check if oil level in compressor is normal; normal oil level of compressor is usually in the
middle of sight glass;
Check if protection setting value (shown below) of high and low pressure is normal;
Item
Setting value
Protection value of high pressure
1.8MPa
Protection value of low pressure
0.35MPa
Protection value of difference between high and low pressure
0.4 MPa
Check if pipeline system of unit is damaged during transportation and handling;
Check if there is pressure in refrigerating system and if there is leaking point of refrigerant;
Step 3: Check Water System
Check if pipeline of cooling and refrigeration water is cleanly flushed and if there are sundries
at the connection part of cooling and water pool with outside, ensure there are no sundries
and foreign matters in pipe.
Check if pressure gauge and thermometer at water side are correctly connected. Pressure
gauge should be installed vertically to the water pipe. Thermometer should be installed in
