Daikin Water Chiller WCC100

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

Maintenance of the refrigerant cycle

Record the condenser water temperature

Record the chiller water temperature

Record the 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

Note any extreme changes in subcooling and/or superheat over a period of time

Warning: A dangerous condition can exist if power is applied to a faulty compressor motor starter that has been burned out.

This is a good time to check all the motor winding resistance to ground.

Enter the resistance between any motor terminal and ground.

If readings are less than 50 megohms, the motor cover must be removed for inspection of the winding prior to starting the unit.

If readings are less than 5 megohms, motor failure is imminent and the motor should be replaced or repaired.

Is the control circuit energized?

If the control circuit has been off and oil is cool, energize oil heaters and allow 24 hours for heater to remove refrigerant from the oil before starting.

Have all electrical connections been checked and tightened?

Has the drain plug in the cooling tower pump been replaced if it was removed at shutdown time the previous season?

Compare the compressor current draw to the nameplate RLA value. Normally, the actual current will be lower, since the nameplate rating represents full load operation.

Compare all pump and fan motor amperages with nameplate ratings.

Warning: This procedure requires trained personnel with PPE!

Enter the leaving water temperature

Enter the saturated refrigerant temperature

Calculate the approach temperature (subtract saturated refrigerant temperature from leaving water temperature)

Note: Daikin's high efficiency heat exchangers have very low design approach temperatures, in the order of one to one and one half degrees F.

Is the approach temperature within the normal range?

If not, excessive tube fouling could be present.

Enter the condenser pressure drop