
Unit Installation
Unit Installation
Charging Hose
Refrigerant R410A : special precaution
ii) Check List Before Installation / Servicing
• Tubing -Refrigerant R410A is more easily affected by dust or 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.
• Tools - Tools used for R410A only (must not be share with other refrigerant)
Gauge manifold and charging hose ,Refrigerant cylinder/charging cylinder
Vacuum pump c/w adapter, Refrigerant recovery machine etc
iii) Handling and Installation Guidelines
Like R22 systems, the handling and installation of R410A 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 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.
b) 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.
c) 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.
d) When charging R410A, ensure that only liquid is being withdrawn from the cylinder or can. This is to
ensure that only the original composition of R410A is being delivered into the system. The liquid
composition can be different from the vapor composition.
e) Normally, the R410A cylinder or can is being equipped with a dip-pipe for liquid withdrawal. However, if
the dip-pipe is not available, invert the cylinder or can so as to withdraw liquid from the valve at the
bottom.