Air Handler
10
7.2 Wire Sizing
Wire size is important to the operation of your equipment. Use the following check list when
selecting the appropriate wire size for your unit.
● Wire size must carry the Minimum Circuit Ampacity (MCA).
table 13
Model
Nominal
CFM
Nominal
Capacity
BTU/H
Electric Heat
Kw
Min. Circuit Ampacity
Max. Fuse or Breaker
(HACR) Ampacity
240V
208V
240V
208V
240V
208V
706
24000
5
3.8
26.9
23.4
30
25
8
6
42.5
36.9
45
40
10
7.5
52.9
45.9
60
50
1150
35000
5
3.8
28.0
24.4
30
25
8
6
43.6
37.8
45
40
10
7.5
54.0
47.0
60
50
15
11.3
54.0/26.0 47.0/22.5
60/30
50/25
20
15
54.0/52.1 47.0/45.1
60/60
50/50
1300
4
2
0
0
0
5
3.8
28.1
24.6
30
25
8
6
43.7
38.1
45
40
10
7.5
54.2
47.1
60
50
15
11.3
54.2/26.0 47.1/22.5
60/30
50/25
20
15
54.2/52.1 47.1/45.1
60/60
50/50
1420
55
000
5
3.8
29.3
25.8
30
25
8
6
44.9
39.3
45
40
10
7.5
55.3
48.3
60
50
15
11.3
55.3/26.0 48.3/22.5
60/30
50/25
20
15
55.3/52.1 48.3/45.1
60/60
50/50
Wire size allows for no more than a 2% voltage drop from the building breaker/fuse panel to
the unit.
Refer to the latest edition of the National Electric Code (NEC) in USA or the Canadian Electric
Code (CSA) in Canada when determining the correct wire size. The following table shows the
current carrying capabilities for copper conductors rated at 75ºC with a 2% voltage drop. Use the
Table 10 to determine the voltage drop per foot of various conductors.
table 14
Maximum Allowable Length in Feet to Limit Voltage Drop to 2% *
Wire
Size(AWG)
Minimum Circuit Ampacity(MCA)
10
15
20
25
30
35
40
45
14
75
50
37
12
118
79
59
47
10
188
125
95
75
63
54
8
301
201
150
120
100
86
75
68
6
471
314
235
188
157
134
118
110
*Based on NEC 1996
VAF-24A308I
VAF-36A308I
VAF-42A308I
VAF-55A308I
