Product Manual

Table Of Contents
Cable sizing according UL/cUL
Calculation method according UL 508A, table 28.1 column 5: allowable ampacities of insulated
copper conductors (75 °C (167 °F)).
Maximum allowed current in function of the wire size (NFPA70 table 310.16)
AWG or kcmil Maximum current
14 20 A
12 25 A
10 35A
8 50 A
6 65 A
4 85 A
3 100 A
2 115 A
1 130 A
Correction factors
Ambient temperature Correction factor
21-25 °C (70-77 °F) 1.05
26-30 °C (78-86 °F) 1.00
31-35 °C (87-95 °F) 0.94
36-40 °C (96-104 °F) 0.88
Calculation method for UL:
Single supply cables (3 phases + 1 PE - configuration (1)):
Add 25 % to the total current (I
tot
from the tables) (see UL 508A 28.3.2: "Ampacity shall
have 125 % of the full load current").
Install the prescribed maximum fuse on each cable
Parallel supply cable (2 x 3 phases + 2 PE - configuration (2)):
Add 25 % to the total current (I
tot
from the tables) and divide by 2
Multiply the ampacity of the cables with 0.8 (see UL 508A table 28.1 continued)
Install fuses of half the size of the recommended maximum fuse size on each cable.
When using 2 x 3 phase + 2 PE as in (3):
Add 25 % to the total current (I
tot
from the tables) and divide by √3
Multiply the ampacity of the cables with 0.8 (see UL 508A table 28.1 continued)
Fuse size: the recommended maximum fuse size divided by √3 on each cable.
Size PE cable:
For supply cables up to AWG8: same size as the supply cables
For supply cables larger than AWG8: use maximum allowed ampacity of the selected
supply cables and compare with value in table below (see CEC Part 1 table 17)
< 100 A: use AWG8
< 200 A: use AWG6
< 300 A: use AWG4
Instruction book
96 2920 7140 42