Special Precautions When Dealing With R407C Unit - McQuay International A08019025531 Manuel D'installation

4MST/MST 101010AR / 101015AR / 101515AR / 151515AR
Indoor Unit 1
4WV OF COMP N2 N1 L
Outdoor Unit
Terminal Block
4WV1 OF1 COMP1 N1
• All wires must be firmly connected.
• All wires must not touch any of the refrigerant piping, compressor or any moving parts of fan motor.
• The connecting wires between the indoor unit and the outdoor unit must be clamped on the wire clamps as shown
in the figure.
• The power supply cord must be equivalent to H05RN-F (245IEC57) which is the minimum requirement.

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 perfor-
mance 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.
• 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.
Power Supply
Indoor Unit 2
4WV OF COMP N2 N1
4WV2 OF2 COMP2 N2 4WV3 OF3 COMP3 N3
Power Supply
L 4WV OF COMP
L N
Power Supply
There must be a double pole switch with minimum
!
3mm contact gap and fuse/circuit breaker as
recommended in the fixed installation circuit.
1-7
Indoor Unit 3
N2 N1 L
Indoor Unit
Terminal Block