Mitsubishi Electric PAA-A18AA1 Service Manual page 11

CAUTION
Risks related to PAA unit service
• When servicing and relocating the PAA unit, do not charge it with a refrigerant different
from the refrigerant specified on the unit.
– If a different refrigerant or air is mixed with the original refrigerant, the refrigerant cycle
may malfunction and the unit may be damaged. Use only recommended refrigerant
specified in outdoor unit (ODU) manual for system operation (ONLY R410A).
• The PAA unit is designed for indoor installation only.
• The PAA unit must be installed downstream (discharge air) side of the furnace.
• Do not alter the cabinet or braze inside the cabinet. Quench all brazed joints with water
or a wet rag to avoid overheating after brazing.
– It may affect the performance of the PAA unit.
• Do not use leak detection additive.
– ODU and PAA unit parts may be damaged by the refrigerant/additive mixture.
Refrigerant leak risks
• The service (technician) shall ensure there is no refrigerant leakage according to local
regulations and standards.
– Refrigerant leakage will affect the performance of the heat pump.
Service guidelines
• For PAA unit piping connections, use flare connection as the equipment was designed
for. Mitsubishi Electric US, Inc. is not responsible for improper brazing connection done
by the service technician.
– Improper brazing connections may cause damage to the PAA unit.
– For pipe flaring, use an R410A flaring tool.
Specifications are subject to change without notice.
PAA-A18, 24, 30, 36, 42AA1/BA1/CA1 and all-
11 © 2022 Mitsubishi Electric US, Inc.