| Table 5.8 - Values of
k for protective conductors |
||||
|
Nature of protective conductor
|
Initial temp.
(°C) |
Final temp
|
Conductor
material |
K
|
|
p.v.c. insulated, not in cable
or bunched |
30
|
160
|
Copper
|
143
|
|
-
|
30
|
160
|
Aluminium
|
95
|
|
-
|
30
|
160
|
Steel
|
52
|
|
-
|
||||
|
p.v.c. insulated, in cable
or bunched |
70
|
160
|
Copper
|
115
|
|
-
|
70
|
160
|
Aluminium
|
76
|
|
-
|
||||
|
Steel conduit or trunking
|
50
|
160
|
Steel
|
47
|
|
-
|
||||
|
Bare conductor
|
30
|
200
|
Copper
|
159
|
|
-
|
30
|
200
|
Aluminium
|
105
|
|
-
|
30
|
200
|
Steel
|
58
|
Extracted from The Electricians Guide Fifth Edition
by John Whitfield
Published by EPA Press Click Here to order your Copy.