Friedrich FPHMR18A3A Service Manual page 54

M M AX. leng g th allow
Indoor unit
24 and 36k Outdoor Units
Piping Work and Refigerant Charge
Pipe length A
Refrigerant Additional Charge
The unit has been filled with refrigerant, but if L (total pipe length) exceeds standard length, additional refrigerant (R410A) change is
required.
For 24K: Additional refrigerant charge=[L-74-4/5(22.8m)
For 36K: Additional refrigerant charge=[L-98-3/7(30m)
O O il trap
When the indoor unit is lower than the outdoor unit, and the height
is larger than 16 feet, an oil bend should be employed for every 16 feet.
Slope： 1/200~1/250
NOTE:
1. To avoid storing too much oil in the oil bend, the oil bend should be as short as possible.
2. The horizontal piping should be sloped down along the refrigerant flow direction, to bring the oil back to compressor. The
slope should be between 1/200 and 1/250.
In order to ensure cooling/ heating performance better, the refrigerant piping should be as short and straight as possible.
54
e e d
INSTALLATION
D
C
B
Pipe length D
A
MAX.length allowed
Outdoor unit
Note:
Indoor
unit
Indoor unit D in the circle is only valid for 36K model.
Pipe length
Outdoor
D ====
C ====
B ::::
Pipe length A
Model
Max. Length Between Indoor Unit
and Outdoor Unit
Max. Length Between Indoor Unit
and Outdoor Unit (Total)
Max. Height Between Indoor Unit
and Outdoor Unit
Max. Height Between Indoor Units
�
E
Piping to each indoor unit
(A/B/C/D/E)
]× 0.807oz/5ft (15g/m)
Total length of piping between all
un i
units
]× 0.807oz/5ft (15g/m)
Max height difference between
indoor unit and outdoor unit (F)
max height difference between
indoor units (G)
Slop e：1/200~1/250
An oil trap should be used every 16 ft
24K
A≤ 65.6(20)
ft./m B≤ 65.6(20)
C ≤ 65.6(20)
A+B+C ≤
ft./m
197(60)
ft./m D ≤ 49(15)
ft./m E ≤ 25(7.5)
18K 24K 36K
ft.
S82 S65 S65
A+BS A+B+Cs A+B+C+DS A+B+C+D+E
ft.
ft. S49
ft. S 25
36K
A≤ 65.6(20)
B≤ 65.6(20)
C ≤ 65.6(20)
D ≤ 65.6(20)
A+B+C+D ≤
246(75)
D ≤ 49(15)
E ≤ 25(7.5)
42K
S65
¾262