Friedrich FPHFC36A3B Wi-Fi Service & Parts Manual page 70

Piping Work and Refigerant Charge
Indoor unit
Max. Pipe
Model
length (L)
9K/12K 8 2 . t f 2 (
18K 98 ft. (30m)
24K/36K 164 ft. (50m)
13.2 Oil trap
When the indoor unit is lower than outdoor unit and height difference is larger than 16.4 ft (5m),
set an oil trap every 16.4 ft (5m) (height difference) on suction piping.
NOTE:
1) To avoid storing too much oil in the oil trap, the oil trap should be as short as possible.
2) The horizontal piping should slope down along the refrigerant flow direction, to bring the oil
back to compressor , the slope is about 1/200 to1/250.
3) In order to ensure cooling/heating performance better, the refrigerant piping should be as short
and straight as possible.
70
INSTALLATION
Pipe length L
Outdoor unit
Max. Height Add. Refrigerant
(L) difference (H)
[exceed 2 ft. (7.6m)]
5 m ) 3 3 . t f 1 ( 0 m ) 0
49 ft. (15m) 0.161 oz/ft (15g/m)
98 ft. (30m) 0.376 oz/ft (35g/m)
Slope: 1/200~1/250
1 . 6 1 z o t f / 1 ( 5 / g m )
Slope: 1/200~1/250
Oil trap