Insulated wire ampacity.

[Josesaucedo]

Does any body know two factors that determine the ampacity of an insulated wire?
I need five factors and I have three already.
1. Material from which the wire is made.
2. Type of insulation used.
3. Ambient or surrounding, air temperature.
4.
5.

thanks for your help.

 

[charlie b]

Two others would include:
(4) Proximity of other current-carrying conductors ? refer to 310.15(B)(2)(a).
(5) Method of routing (e.g., underground versus free air versus in conduit)

 

[snewman24]

6. Wire diameter

 

[Pierre C Belarge]

7.wire length

 

[bob]

1. Material Cu or AL
2. Cross sectional area
3. Insulation
4. Operating Temperature
5. installation in free air, conduit, duct bank, underground.

 

[charlie b]

7.wire length

I think not, or at least not directly.

Wire length might influence your choice of wire diameter, in that you might want to compensate for voltage drop. That is the only way I can think of that length could indirectly influence ampacity.

 

[kulukoy]

Thermal resistance is one factor per IEC 287.

 

[johnny watt]

Amount of time that current is flowing.
Hertz as it pertains to skin effect

 

[Pierre C Belarge]

The OP did not mention any variables
We have been taught the length and diameter are two of the determing factors in ampacity of a conductor. If either is changed, the ampacity of the conductor will be affected.

 

[charlie b]

Not length, Pierre. Length does not impact ampacity. Length might impact your choice of conductor, in that you might pick a larger conductor if you were concerned about voltage drop. But neither the ampacity of the original conductor nor the ampacity of the "upsized" conductor would be changed if you changed the length of the conductor.