Air conditioning: Adjustments

SERVICE PRECAUTIONS

Care should be taken when handling the components in the refrigeration system. Units must not be lifted by their hoses, pipes or capillary lines. Hoses and lines must not be subjected to any twist or stress. Ensure that hoses are positioned in their correct run before tightening couplings, and ensure that all clips and supports are used. Torque wrenches of the correct type must be used when tightening refrigerant connections to the stated value. An additional spanner must be used to hold the union to prevent twisting of the pipe.

Before connecting any hose or pipe ensure that refrigerant oil is applied to the seat of the new ’O’ ring but not to the threads.

Check the oil trap for the amount of oil lost.

All protective plugs must be left in place until immediately prior to connection.

The receiver/drier contains desiccant which absorbs moisture. It must be positively sealed at all times.

CAUTION: Whenever the refrigerant system is opened, the receiver/drier must be renewed immediately before evacuating and recharging the system.

Use alcohol and a clean cloth to clean dirty connections.

Ensure that all new parts fitted are marked for use with R134a.

Refrigerant oil

Use an approved refrigerant lubricating oil:

Sarden SP-10 Unipart SP - 10

CAUTION: Do not use any other type of refrigerant oil.

Refrigerant oil easily absorbs water and must not be stored for long periods. Do not pour unused oil back into the container.

When renewing system components, add the following quantities of refrigerant oil:

Condenser 30cm₃³ Evaporator 30cm₃ Pipe or hose 10cm₃ Receiver drier 30cm

Total amount of oil in the system: 135cm³

A new compressor is sealed and pressurised with Nitrogen gas, slowly release the sealing cap, gas pressure should be heard to release as the seal is broken.

NOTE: A new compressor should always have its sealing cap in place and must not be removed until immediately prior to fitting.

Fitting a new compressor

A new compressor is supplied with an oil fill (Qcm₃³) of 135 cm .

A calculated quantity of oil must be drained from a new compressor before fitting.

To calculate the quantity to be drained:

1. Remove the drain plug from the OLD compressor.
2. Invert the compressor and gravity drain the oil in a calibrated measuring cylinder. Rotating the compressor clutch plate will assist complete draining.₃
3. Note the quantity of oil drained (Ycm ).
4. Calculate the quantity of oil to be drained from the NEW compressor using the following formula:

Qcm3 - (Ycm3 + 20cm3) = Xcm3