Daikin Centrifugal Compressor Water Chiller HSC113

Maintain a log of the operating conditions, and check that the unit has the proper oil and refrigerant charge.

Suction line temperature at the compressor

Calculate the suction superheat by subtracting the saturated temperature equivalent of the suction pressure from the suction line temperature.

Test operation of Pump Interlocks

Test operation of Guardistor and Surgeguard

Test operation of High and Low Pressure Cutouts

Test operation of Oil Pump Pressure Differential Cutout

Test operation of Oil Pump Time Delay

At least once a quarter, all equipment protection controls except compressor overloads should be made to operate and their operating points checked.

Check if Pump interlocks and flow switches interrupt the control circuit when tripped.

Inspect and clean the contactors in the motor starter

Is the chiller subject to freezing temperatures?

If yes, drain the condenser and chiller of all water.

Did you use dry air to force all water out?

Did you remove the condenser heads?

Warning: Water left in the piping and vessels can rupture these parts if subjected to freezing temperature.

Did you circulate antifreeze through the water circuits?

Take measures to prevent the shutoff valve in the water supply line from being accidentally turned on.

Did you remove the water pump drain plug?

Warning: This maintenance check requires trained personnel with PPE!

Enter the leaving water temperature

Enter the saturated refrigerant temperature

Calculate the approach temperature by subtracting the saturated refrigerant temperature from the leaving water temperature

Is the approach temperature within the range of one to one and one half degrees F?

If not, excessive tube fouling could be present. Higher than normal discharge pressure and motor current are also indicators.

Enter the condenser pressure drop

Is the condenser pressure drop normal?

If not, confirm future flow rates.

Maintenance of the refrigerant cycle includes maintaining a log of the operating conditions, and checking that the unit has the proper oil and refrigerant charge.

Record the condenser water temperature

Record the chiller water temperature

The suction line temperature at the compressor should be taken at least once a month.

Record the suction line temperature at the compressor

Subtracting the saturated temperature equivalent of the suction pressure from this will give the suction superheat.