Specifications

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or R407Cor R407C

or R407C

Special Precautions When Dealing With Refrigerant R407C Unit

1) What is new refrigerant R407C?

R407C is a zeotropic refrigerant mixture which has Zero Ozone Depletion Potential (ODP = 0) and

thus conformed to the Montreal Protocol regulation. It requires Polyol-ester oil (POE) oil for its

compressor’s lubricant. Its refrigerant capacity and performance are about the same as the

refrigerant R22.

2) Components

Mixture weight composition R32(23%), R125(25%), R134a(52%)

3) Characteristic

• R407C liquid and vapor components have different compositions when the fluid evaporates or

condenses. Hence, when leak occurs and only vapor leaks out, the composition of the refrigerant

mixture left in the system will change and subsequently affect the system performance. DO NOT

add new refrigerant to leaked system. It is recommended that the system should be evacuated

thoroughly before recharging with R407C.

• When refrigerant R407C is used, the composition will differ depending on whether it is in gaseous or

liquid phase. Hence when charging R407C, ensure that only liquid is being withdrawn from the

cylinder or can. This is to make certain that only original composition of R407C is being charged into

the system.

• POE oil is used as lubricant for R407C compressor, which is different from the mineral oil used for

R22 compressor. Extra precaution must be taken not to expose the R407C system too long to moist

air.

4) Check list before installation/servicing

• Tubing

Refrigerant R407C is more easily affected by dust of moisture compared with R22, make sure to

temporarily cover the ends of the tubing prior to installation

• Compressor oil

No additional charge of compressor oil is permitted.

• Refrigerant

No other refrigerant other that R407C

• Tools

Tools specifically for R407C only (must not be used for R22 or other refrigerant)

i) Manifold gauge and charging hose

ii) Gas leak detector

iii) Refrigerant cylinder/charging cylinder

iv) Vacuum pump c/w adapter

v) Flare tools

vi) Refrigerant recovery machine

5) Handling and installation guidelines

Like R22 system, the handling and installation of R407C system are closely similar. All precautionary

measures; such as ensuring no moisture, no dirt or chips in the system, clean brazing using nitrogen, and

thorough leak check and vacuuming are equally important requirements. However, due to zeotropic

nature of R407C and its hydroscopic POE oil, additional precautions must be taken to ensure optimum

and trouble-free system operation.

a) During installation or servicing, avoid prolong exposure of the internal part of the refrigerant system

to moist air. Residual POE oil in the piping and components can absorb moisture from the air.