3 Wiring and Connection
3.1.2 Main Circuit Wire
3-6
3.1.2
Main Circuit Wire
This section describes wires used in the main circuit.
(1) Wire Types
Use the following type of wire for main circuit.
The following table shows the wire sizes and allowable currents for three wires.
Use wires with specifications equal to or less than those shown in the table.
Note: These are reference values for 600-V-grade, heat-resistant, PVC-insulated wire.
• The specified wire sizes are for use when the three lead cables are bundled and when
the rated electric current is applied with a surrounding air temperature of 40
°
C.
• Use a wire with a minimum withstand voltage of 600 V for the main circuit.
• If cables are bundled in PVC or metal ducts, take into account the reduction of the
allowable current.
• Use a heat-resistant wire under high surrounding air or panel temperatures, where
polyvinyl chloride insulated wires will rapidly deteriorate.
Cable Type
Allowable Conductor Temperature
(
°
C)
Symbol
Name
IV
600 V polyvinyl chloride insulated wire
60
HIV
600 V grade heat-resistant polyvinyl chloride insulated wire
75
Nominal Cross
Section Diameter
(mm
2
)
AWG Size
Configuration
(Number of Wires/
mm)
Conductive
Resistance (
Ω
/
km)
Allowable Current at Surrounding Air
Temperature (A)
30
°
C
40
°
C
50
°
C
0.5
(20)
19/0.18
39.5
6.6
5.6
4.5
0.75
(19)
30/0.18
26
8.8
7
5.5
0.9
(18)
37/0.18
24.4
9
7.7
6
1.25
(16)
50/0.18
15.6
12
11
8.5
2
(14)
7/0.6
9.53
23
20
16
3.5
(12)
7/0.8
5.41
33
29
24
5.5
(10)
7/1.0
3.47
43
38
31
8
(8)
7/1.2
2.41
55
49
40
14
(6)
7/1.6
1.35
79
70
57
22
(4)
7/2.0
0.85
91
81
66
38
(1)
7/2.6
0.49
124
110
93
60
(2/0)
19/2.0
0.30
170
150
127
100
(4/0)
19/2.6
0.18
240
212
179