York Centrifugal Chiller YKWTWSK75DDGS

Test all system joints for refrigerant leaks with a leak detector

Were any refrigerant leaks found?

Repair any detected refrigerant leaks before long-term shutdown

Periodically check the tightness of the system during idle periods

Drain water from cooling tower, condenser, condenser pump, chilled water system, chilled water pump, and coils if freezing temperatures are expected

Open drains on evaporator and condenser liquid heads to ensure complete drainage

Drain water from additional systems if applicable

Disable the clock on the SETUP Screen to conserve battery

Check graphic control centre (OptiView) displays.

Check for any signs of dirty or fouled condenser tubes.

Is the compressor in operation?

Enter the bearing oil pressure on the SYSTEM Screen.

Check the oil level in the oil reservoir.

Check the refrigerant charge (See Refrigerant Charge Checking)

7.4.1 Checking The Refrigerant Charge

Record the refrigerant level after initial charging

Is the refrigerant level visible in the sight glass?

Ensure the system is shut down before checking and trimming the refrigerant charge

Has the pressure and temperature equalised between the condenser and evaporator?

Connect a high capacity vacuum pump with indicator to the system charging valve and start the pump.

Open wide all system valves and ensure all valves to the atmosphere are closed.

Operate the vacuum pump until a wet bulb temperature of 0°C or a pressure of 5 mm Hg (absolute) is reached.

Circulate warm water (not to exceed 50°C) through the evaporator and condenser tubes to dehydrate the shells.

Close the system charging valve and the stop valve between the vacuum indicator and the vacuum pump. Disconnect the vacuum pump leaving the vacuum indicator in place.

Hold the vacuum in the system for 8 hours. Record any rise in pressure.

After 8 hours, has the wet bulb temperature in the vacuum indicator remained below 4.4°C or pressure below 6.3 mm Hg?

If the vacuum does not hold for 8 hours within the limits specified, find and repair the leak.

7.1.6 Annually (more often if necessary)

Drain and replace the oil in the compressor oil sump

Verify the nominal oil charge for the compressor is 75.7 litres of York 'K' oil

Ensure only York 'K' refrigeration oil is used in the centrifugal compressor

Keep oil tightly capped until used to prevent moisture absorption

Open the oil charging valve and pump oil until the level is midway in the upper sight glass