Start-Up; Adding Refrigerant - Single-Zone Systems; Adding Refrigerant - Multi-Zone Systems - Lennox MPA009S4S Service Manual

19. Start-Up

19.1. Adding Refrigerant - Single-Zone Systems

The outdoor unit is factory-charged with refrigerant. Calculate the additional refrigerant required according to the diameter
and the length of the liquid pipe between the outdoor unit and indoor unit connections.
Be sure to add the proper amount of additional refrigerant. Failure to do so may result in reduced performance.
NOTE: Interconnecting pipe work between outdoor and indoor units must be 10 ft. or longer.
NOTE: Do not remove refrigerant for line lengths less than 25 ft. R-410A is a blended refrigerant. If you must remove
charge, it is necessary to remove the entire charge and weigh in the new charge.
System Size (KBtu)
09
12
18
24
36
48

19.2. Adding Refrigerant - Multi-Zone Systems

The outdoor unit is factory-charged with refrigerant. Calculate the additional refrigerant required according to the length of
the liquid pipe (one way) between the outdoor unit and indoor unit connections.
Be sure to add the proper amount of additional refrigerant. Failure to do so may result in reduced performance.
NOTE: Interconnecting pipe work between outdoor and indoor units must be 10 ft. or longer.
NOTE: Do not remove refrigerant for line lengths less than 25 ft. R-410A is a blended refrigerant. If you must remove
charge, it is necessary to remove the entire charge and weigh in the new charge.
System
Two-port
Three-port
Four-port
Five-port
Table 1.
Pipe Length
>25 ft. (7.5m)
>25 ft. (7.5m)
>25 ft. (7.5m)
>25 ft. (7.5m)
>25 ft. (7.5m)
>25 ft. (7.5m)
Table 2.
Pre-charge
Pipe Length
0.16 oz ((L1 ft + L2 ft) - 50 ft)
50 ft. (15 m)
0.005 kg ((L1 m + L2 m) - 15 m)
0.16 oz ((L1 ft + L2 ft + L3 ft) - 75 ft)
75 ft. (23 m)
0.005 kg ((L1 m + L2 m + L3 m) - 23 m)
0.16 oz ((L1 ft + L2 ft + L3 ft + L4 ft) - 100 ft)
100 ft. (30 m)
0.005 kg ((L1 m + L2 m + L3 m + L4 m) - 30 m)
0.16 oz ((L1 ft + L2 ft + L3 ft + L4 ft + L5 ft) - 125 ft)
125 ft. (38 m)
0.005 kg ((L1 m + L2 m + L3 m + L4 m + L5 m) - 38 m)
Adding Refrigerant
Adding Refrigerant
Amount of Refrigerant to add
90
Amount of Refrigerant to add
0.161 oz/ft (15g/m)
0.161 oz/ft (15g/m)
0.161 oz/ft (15g/m)
0.322 oz/ft (30g/m)
0.322 oz/ft (30g/m)
0.322 oz/ft (30g/m)