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)
1.
!
Manifold gauge and charging hose
2.
!
Gas leak detector
3.
!
Refrigerant cylinder/charging cylinder
4.
!
Vacuum pump c/w adapter
5.
!
Flare tools
6.
!
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.
5.1) Filter-dryer must be installed along the liquid line for all R407C air conditioners. This is to minimise the
contamination of moisture and dirt in the refrigerant system. Filter-dryer must be of molecular sieve type. For a
heat-pump system, install a two-way flow filter dryer along the liquid line.
5.2) During installation or servicing, avoid prolong exposure of the internal part of the refrigerant system to
moist air. Residual POE oils in the piping and components can absorb moisture from the air.
5.3) Ensure that the compressor is not expose to open air for more than the recommended time specified by its
manufacturer (typically less than 10 minutes). Removed the seal-plugs only when the compressor is about to be
brazed.
5.4) The system should be thoroughly vacuumed to 1.0 Pa (-700mmHg) or lower. This vacuuming level is more
stringent than R22 system so as to ensure no incompressible gas and moisture in the system.
5.5) When charging R407C, ensure that only liquid is being withdrawn from the cylinder or can. This is to ensure
That only the original composition of R407C is being delivered into the system. The liquid composition can be
different from the vapour composition.
