Daikin EWAD740C-SS [274/304] Procedure to clean the refrigerant circuit in case of frozen evaporators

Procedure to Clear the Refrigerant Circuit in Case of Frozen Evaporators ESIE10-01

3–74 Part 3 – Troubleshooting

5.2 Procedure to Clean the Refrigerant Circuit in Case of Frozen Evaporators

If water is detected in the refrigerant circuit after an evaporator damage, the following procedure

should be executed to clear the system.

Step Action

1 Inspection and cleaning of compressor.

Vacuum and heat-up the compressor to remove moisture.

Fill with oil and N

2 Cleaning & drying refrigerant circuit.

Cleaning components:

■ Expansion valve body.

■ Liquid line solenoid valve.

■ Suction and liquid line.

Replace components:

■ Sight glass

■ Drier filter element by high density filter

■ Compressor oil

Actions:

■ Drill a hole on the bottom of the condenser headers to remove water.

■ Braze the drilled holes.

■ Draw the rags through the suction and liquid line.

■ Blow-dry N2 through all the pipes.

■ Drain compressor oil

■ Vacuum the whole installation:

Check on a regular basis the condition of the oil of the vacuum pump. If the vacuum

oil becomes milky, it should be replaced by new vacuum oil. The crankcase heater

must be activated. It is advisable to connect a second heater tape at the suction of

the compressor.

■ Stop the vacuum and purge with dry nitrogen.

■ Restart the vacuum of the installation; check after a couple of hours the condition of

the vacuum oil. If OK the unit can be recharged.

■ Charge the unit with R-134a.

■ Start the unit & re-commissioning.

■ After 24 hours replace HD filter by new HD filter & replace compressor oil.

■ Check oil contamination with measuring kit.

■ After 48 hours replace HD filter by normal filter drier + check sight glass and

pressures.

3 Find the cause of this evaporator breakdown and take the necessary actions to prevent

recurrence in the future.