Electric Control Working Environment; Start-Up; Adding Refrigerant - Single-Zone Systems; Adding Refrigerant - Multi-Zone Systems - Lennox MMA018SM4 Service Manual

15.2. Electric Control Working Environment.

• Input voltage: 230V.
• Input power frequency: 60Hz.
• Indoor fan standard working amp.: <1A
• Outdoor fan standard working amp.: <1.5A.
• Four-way valve standard amp.: <1A

16. Start-Up

16.1. 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.
Table 10. Adding Refrigerant
System Size
(KBtu)
18
24
30
36
48
60
Note: 1/4" = 0.16 oz/ft; 3/8" = 0.32 oz/ft

16.2. 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 each indoor unit connection.
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.
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.
Pre-charge
System
Pipe Length
Two-port 50 ft. (15 m)
Three-
75 ft. (23 m)
port
Four-port 100 ft. (30 m)
Five-port 125 ft. (38 m)
Amount of Refrigerant
Pipe Length
>25 (7.5) 0.16 oz/ft (15g/m)
>25 (7.5) 0.32 oz/ft (30g/m)
>25 (7.5) 0.32 oz/ft (30g/m)
>25 (7.5) 0.32 oz/ft (30g/m)
>25 (7.5) 0.32 oz/ft (30g/m)
>25 (7.5) 0.32 oz/ft (30g/m)
Table 1.
0.16 oz [(L1 ft + L2 ft) - 50 ft]
0.005 kg [(L1 m + L2 m) - 15 m]
0.16 oz [(L1 ft + L2 ft + L3 ft) - 75 ft] 0.005 kg [(L1 m + L2 m + L3 m) - 23 m]
0.16 oz [(L1 ft + L2 ft + L3 ft + L4 ft) - 100 ft] 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] 0.005 kg [(L1 m + L2 m + L3 m + L4 m + L5
m) - 38 m]
to add
Adding Refrigerant
Amount of Refrigerant to add
70