Hitachi RAS-FSXNSE Series Instruction Manual page 42

PIPING WORK AND REFRIGERANT CHARGE
• 2 and 3 Units Combination
Indoor unit side
Indoor unit side
The refrigerant oil is stagnated to the unit stopped.
Oil trap min 200 mm
Oil trap min 200 mm
Indoor unit side
Max 300 mm
• 4 Units Combination
Indoor unit side
Indoor unit side
The refrigerant oil is stagnated to the unit stopped.
Oil trap min
Oil trap min
200 mm
200 mm
Max 300 mm Max 300 mm
3 In case that the piping length between outdoor units is 2m or
more, the oil trap for the gas pipe should be provided so that
accumulation of refrigerant oil may not occur.
• 2 and 3 Units Combination
Less than 2m
Indoor unit side
Less than 2 m
2m or More
20 PMML0479 rev.4 - 11/2018
Oil trap min 200 mm
Max 300 mm Max 300 mm
Oil trap min Oil trap min
200 mm 200 mm
Max 300 mm
Max 300 mm
Less than 2 m
Oil trap
min 200 mm
Indoor unit side
Less than 2 m
2 m or more
• 4 Units Combination
Less than 2m
Indoor unit side
Less than
Less than 2 m
2 m
Less than 2 m
Oil trap
Indoor unit side
min 200 mm
Less than
Less than
2 m
2 m or more
2 m
Less than 2 m
2 m or more
10 m or more
4 Place the outdoor unit pipe horizontally or with the pipe
slanted downward towards the indoor unit side so that
accumulation of refrigerant oil may not occur in the pipe.
• 2 and 3 Units Combination
Indoor unit side
Indoor unit side
Oil trap
min 200 mm
Less than 2 m
2 m or more
Less than 2 m
2m or More
Oil trap
Oil trap
min 200 mm
min 200 mm
Less than
2 m
2 m or more
Refrigerant oil accumulates in the pipe.