Mitsubishi Electronics PDFY-P24NMU-E Precautions for devices that use R410A refrigerant

Warning:

•Note the following when building a heater in the air conditioning system.

-Leave enough space between units for proper ventilation so that the indoor unit temperature does not exceed 40˚C when windless.

-Keep the heater clean, and take appropriate measures so that the indoor unit does not suck in the dust particles that accumulate on the heater.

-Use the optional heater cable (PAC-YU24HT) to perform an interlocked operation with indoor units.

-Do not build a heater inside the indoor unit.

Recommended circuit

Wiring diagram

	88H	FS1	H1
	R
1-phase power	S	FS2
supply
	88H		H2
208V, 230V/60Hz		FS1
	R

S

FS2

26H

88H

Control board

CN24

FS1, 2 ----- Thermal fuse

H1, H2 ----- Heater

26H --------- Overheat protection

thermostat

88H --------- Electromagnetic contactor

2

2.Precautions for devices that use R410A refrigerant

Caution:

•Do not use the existing refrigerant piping.

-The old refrigerant and refrigerator oil in the existing piping con- tains a large amount of chlorine which may cause the refrigerator oil of the new unit to deteriorate.

•Use refrigerant piping made of C1220 (Cu-DHP) phosphorus deoxidized copper as specified in the *JIS H3300 “Copper and copper alloy seamless pipes and tubes”. In addition, be sure that the inner and outer surfaces of the pipes are clean and free of hazardous sulphur, oxides, dust/dirt, shaving particles, oils, moisture, or any other contaminant.

-Contaminants on the inside of the refrigerant piping may cause the refrigerant residual oil to deteriorate.

*JIS: Japanese Industrial Standard

•Store the piping to be used during installation indoors and keep both ends of the piping sealed until just before brazing. (Store elbows and other joints in a plastic bag.)

-If dust, dirt, or water enters the refrigerant cycle, deterioration of the oil and compressor trouble may result.

•Use ester oil, ether oil or alkylbenzene (small amount) as the refrigerator oil to coat flares and flange connections.

-The refrigerator oil will degrade if it is mixed with a large amount of mineral oil.

•Use liquid refrigerant to fill the system.

-If gas refrigerant is used to seal the system, the composition of the refrigerant in the cylinder will change and performance may drop.

•Do not use a refrigerant other than R410A.

-If another refrigerant (R22, etc.) is used, the chlorine in the refrig- erant may cause the refrigerator oil to deteriorate.

•Use a vacuum pump with a reverse flow check valve.

-The vacuum pump oil may flow back into the refrigerant cycle and cause the refrigerator oil to deteriorate.

•Do not use the following tools that are used with conventional refrigerants.

(Gauge manifold, charge hose, gas leak detector, reverse flow check valve, refrigerant charge base, vacuum gauge, refriger- ant recovery equipment)

-If the conventional refrigerant and refrigerator oil are mixed in the R410A , the refrigerant may deteriorated.

-If water is mixed in the R410A,the refrigerator oil may deteriorate.

-Since R410A does not contain any chlorine, gas leak detectors for conventional refrigerants will not react to it.

•Do not use a charging cylinder.

-Using a charging cylinder may cause the refrigerant to deteriorate.

•Be especially careful when managing the tools.

-If dust, dirt, or water gets in the refrigerant cycle, the refrigerant may deteriorate.