Special Precaution When Dealing With R410A Unit; Special Precaution When Dealing With R407C Unit; Vacuuming And Charging - McQuay SLC Serie Manual De Instalación

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.
Purging The Piping And The Indoor Unit
Except for the outdoor unit which is pre-charged with
refrigerant R22, the indoor unit and the refrigerant
connection pipes must be air-purged because the air
containing moisture that remains in the refrigerant cycle may
cause malfunction of the compressor.
• Remove the caps from the valve and the service port.
• Connect the center of the charging gauge to the vacuum
pump.
• Connect the charging gauge to the service port of the
3-way valve.
• Start the vacuum pump. Evacuate for approximately
30 minutes. The evacuation time varies with different
vacuum pump capacity. Confirm that the charging gauge
needle has moved towards -76mmHg (0~76mmHg).
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VACUUMING AND CHARGING

Caution
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1-10
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, a poisonous gas may occur.
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) 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
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.
If the gauge needle does not move to 0~76mmHg, be
sure to check for gas leaks (using the refrigerant
detector) at flare type connection of the indoor and
outdoor unit and repair the leak before proceeding to
the next step.
Close the valve of the changing gauge and stop the
vacuum pump.
On the outdoor unit, open the suction valve (3 way) and
liquid valve (2 way) (in anti-clockwise direction) with
4mm key for hexagon sacked screw.