Daikin Water Chilling Unit CUW120A5Y

Warning: Ensure the cooling tower is turned off before starting the cleaning process.

Is the cooling tower turned off?

If the cooling tower is not turned off, stop the procedure and report to the maintenance team.

Is there any visible scale or fungus inside the cooling tower?

If scale or fungus is visible, proceed with the cleaning process.

Upload a photo of the condenser before cleaning.

Describe the condition of the condenser before cleaning.

Was the cleaning process successful?

- Check refrigerant charge using the condenser liquid level gauge (refrigerant is within range on the gauge)

- Check refrigerant oil charge using the compressor oil gauge (refrigerant oil is within range on the gauge)

- Check water quality (according to JIS K0101 or this manual; see water quality standards on page 50);

Caution: Never touch parts which tend to become hot such as compressors and refrigerant piping. Doing so could result in skin burning. Do not attempt to run the compressor by pushing the magnetic contactor with your finger. Doing so could result in electrical shock or fire.

Check open-closed state of all valves before usage

Check valves against instructions given in the operation manual and on the nameplate

Safety valves are open while the equipment is running

If valves are open or closed when they shouldn't be, water may leak. In worse cases, the equipment may catch fire or explode.

Before inspecting: It would be a good idea to read “SAFETY” once more before starting inspection. Be sure to let other maintenance technicians know that you are going to inspect the chiller. Push the STOP/RESET button to stop the unit. Place an “under inspection” warning sign on the switch box.

Drain some of the water from the air purge plug

If the water is dirty, replace all the water in the system

Warning: This procedure requires trained personnel with PPE!

Is the stop valve on the condenser outlet closed?

Did the pressure switch (Low pressure protection) trip?

Is the compressor discharge stop valve shut?

Note: Do not short-circuit the pressure switch (Low pressure protection) or the temperature switch (discharge gas) for any reason whatsoever

Operate the compressor for about 15 minutes before performing pump down

Sign off on the Chilling Unit Pump Down

To maintain the unit in prime operating condition, check the following items daily, making adjustments where necessary and keeping a record of all checks. Values under “Passing grade” are indicated for chiller under typical operating conditions.

Check discharge pressure gauge (1.1–1.7 MPa when cooling; 1.5–1.8 MPa when heating)

Check discharge pressure difference between left and right compressors (for 2-compressor circuits, max. 0.1 MPa)

Check suction pressure using the compound gauge (0.3–0.6 MPa when cooling; 0.3–0.6 MPa when heating)

Check suction pressure difference between left and right compressors (for 2-compressor circuits, max. 0.05 MPa)

Check power supply voltage with a voltmeter (within ±10% of rated voltage)

Check condenser water outlet temperature (30–40 °C)

Check chilled (hot) water outlet temperature (5–10 °C when cooling; 40–45 °C when heating)

Check for abnormal vibrations and noises (no abnormal vibrations or noises)