capicity for wire

[cactusjack]

What is the rated capicity for a 25" run of # 4 ga
stranded wire in amps ?

 

[ryan_618]

Re: capicity for wire

What is the conductor made of? What is the insulation? Is it in a conduit? Is it underground? Is it in free air? Need more information, please

 

[notwellman]

Re: capicity for wire

see nec table 310-13. allowable ampacities of insulated conductors in raceway, cable or earth (direct buried) based on ambient temperature of (30 degrees C) for copper conductor with a temperature rating 90 degrees C AWG 4 would be 95 amps maximum. safer to go bigger than smaller

 

[notwellman]

Re: capicity for wire

have to add - not more than (3) three conductors in raceway, cable or earth

 

[iwire]

Re: capicity for wire

4 AWG copper not more than 3 current carrying together is rated 70 amps at 60C, 85 amps at 75C, and 95 amps at 90C.

I doubt highly that your equipment is rated 90C so forget that.

It will be either 60C or 75C rated wire or terminals, you have to go with the lowest temperature rating of either the wire or terminals.

 

[heco]

Re: capicity for wire

Originally posted by iwire:
4 AWG copper not more than 3 current carrying together is rated 70 amps at 60C, 85 amps at 75C, and 95 amps at 90C.

I doubt highly that your equipment is rated 90C so forget that.

It will be either 60C or 75C rated wire or terminals, you have to go with the lowest temperature rating of either the wire or terminals.

 

[heco]

Re: capicity for wire

The # 4 cu wire is sized based on the termination of 60c table as it is less than 100 am and smaller than #1..see ii0-14.c for temp termination limit....

 

[justin]

Re: capicity for wire

also see; section 110.14C(1)(a)(3). Conductors with higher temp ratings if the equipment is listed and identified for use with such conductors.

 

[iwire]

Re: capicity for wire

Hi heco, Welcome to the Forum.

The # 4 cu wire is sized based on the termination of 60c table as it is less than 100 amp and smaller than #1

Most times that is 100% correct, however if the termination is marked 75C you can base your ampacity at that higher temp.

110.14(C)(1) Equipment Provisions. The determination of termination provisions of equipment shall be based on 110.14(C)(1)(a) or (C)(1)(b). Unless the equipment is listed and marked otherwise, conductor ampacities used in determining equipment termination provisions shall be based on Table 310.16 as appropriately modified by 310.15(B)(1) through (6).

Bob