Overall Checking; Special Precautions When Dealing With R410A Unit; Special Precautions When Dealing With R407C Unit - McQuay D Serie Manual De Instalación

Ensure the following, in particular:-
1) The unit is mounted solidly and rigid in position.
2) Piping and connections are leak proof after charging.
3) Proper wiring has been done.
Drainage check:- Pour some water into left side of drain pan
(drainage are in right side of unit).
• Test run:
1) Conduct a test run after water drainage test and gas leakage test.
2) Watch out for the following:-
a) Is the electric plug firmly inserted into the socket?
b) Is there any abnormal sound from unit?
c) Is there smooth drainage of water?

SPECIAL PRECAUTIONS WHEN DEALING WITH R410A UNIT

R410A is a new HFC refrigerant which does not damage
the ozone layer. The working pressure of this new refriger-
ant is 1.6 times higher than conventional refrigerant (R22),
thus proper installation / servicing is essential.
• Never use refrigerant other than R410A in an air condi-
tioner which designed to operate with R410A.
• POE oil is used as lubricant for R410A compressor,
which is different from the mineral oil used for R22 com-
pressor. During installation or servicing, extra precau-
tion must be taken not to expose the R410A system too
long to moist air. Residual POE oil in the piping and
components can absorb moisture from the air.
• To prevent mischarging, the diameter of the service port
on the flare valve is different from that of R22.

SPECIAL PRECAUTIONS WHEN DEALING WITH R407C UNIT

• R407C is a zeotropic refrigerant mixture which has zero ozone
depletion potential 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.
• POE oil is used as lubricant for R407C compressor, which is
different from the mineral oil used for R22 compressor. During
installation or servicing, extra precaution must be taken not to
expose the R407C system too long to moist air. Residual POE
oil in the piping and components can absorb moisture from the
air.
• 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.

OVERALL CHECKING

• Check that:
1) Condenser fan is running, with warm air blowing off the
condensing unit.
2) Evaporator blower is running and discharge cool air.
3) The remote controller incorporates a 3 minute delay in the circuit.
Thus, it requires about 3 minutes before the outdoor condensing
unit can start up.
• Use tools and materials exclusively for refrigerant
R410A. Tools exclusively for R410A are manifold valve,
charging hose, pressure gauge, gas leak detector, flare
tools, torque wrench, vacuum pump and refrigerant cyl-
inder.
• As an R410A air conditioner incurs higher pressure than
R22 units, it is essential to choose the copper pipes cor-
rectly. Never use copper pipes thinner than 0.8mm even
though they are available in the market.
• If the refrigerant gas leakage occurs during installation /
servicing, be sure to ventilate fully. If the refrigerant gas
comes into contact with fire, highly hazardous gas may
be produced.
• When installing or removing an air conditioner, do not
allow air or moisture to remain in the refrigerant cycle.
• No additional charge of compressor oil is permitted.
• No other refrigerant other than R407C.
• Tools specifically for R407C only (must not be used for R22 or
other refrigerant)
i)
ii)
iii)
iv)
v)
vi)
• 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.
1-12
Manifold gauge and charging hose
Gas leak detector
Refrigerant cylinder/charging cylinder
Vacuum pump c/w adapter
Flare tools
Refrigerant recovery machine