|
Notice: NEC is a registered trademark of the National Fire Protection
Association, Inc. All NEC references by Electrical Helper are
interpretations of the NEC by the Electrical Helper staff and are not
NEC statements. The official position of the NEC requires that the NEC
be referred to in its entirety. |
| Table B.310.11
Adjustment Factors for More Than Three Current-Carrying Conductors in
a Raceway or Cable with Load Diversity |
| Number of
Current- Carrying Conductors |
Percent of
Values in Tables as Adjusted for Ambient Temperature if Necessary
|
| 4 – 6
|
80
|
| 7 – 9
|
70
|
| 10 – 24
|
70*
|
| 25 – 42
|
60*
|
| 43 – 85
|
50*
|
| *These factors
include the effects of a load diversity of 50 percent. |
| FPN: The
ampacity limit for the number of current-carrying conductors in 10
through 85 is based on the following formula. For greater than 85
conductors, special calculations are required that are beyond the
scope of this table. |
|
|
where:
A1= ampacity from Table 310.16; Table 310.18; Table B.310.1; Table
B.310.6; and Table B.310.7 multiplied by the appropriate factor from
Table B.310.11.
N= total number of conductors used to obtain multiplying factor from
Table B.310.11
E= desired number of current-carrying conductors in the raceway or
cable
A2= ampacity limit for the current-carrying conductors in the raceway
or cable |
| |