| Table
4.3 Correction factors to current rating for ambient temperature
-------------- (Ca) |
||||
|
Ambient temperature
|
Type of insulation
|
|||
|
(°C)
|
70°C p.v.c
|
85°C rubber
|
70°C m.i
|
105°C m.i
|
|
25
|
1.03 (1.03)
|
1.02 (1.02)
|
1.03 (1.03)
|
1.02 (1.02)
|
|
30
|
1.00 (1.00)
|
1.00 (1.00)
|
1.00 (1.00)
|
1.00 (1.00)
|
|
35
|
0.94 (0.97)
|
0.95 (0.97)
|
0.93 (0.96)
|
0.96 (0.98)
|
|
40
|
0.87 (0.94)
|
0.90 (0.95)
|
0.85 (0.93)
|
0.92 (0.96)
|
|
45
|
0.79 (0.91)
|
0.85 (0.93)
|
0.77 (0.89)
|
0.88 (0.93)
|
|
50
|
0.71 (0.97)
|
0.80 (0.91)
|
0.67 (0.86)
|
0.84 (0.91)
|
|
55
|
0.61 (0.84)
|
0.74 (0.88)
|
0.57 (0.79)
|
0.80 (0.89)
|
|
Figures in brackets apply to semi-enclosed
fuses
used for overload protection |
||||
Extracted from The Electricians Guide Fifth Edition
by John Whitfield
Published by EPA Press Click Here to order your Copy.