EGC insulation rating for circuits <=1000V

[Carultch]

As far as bare, I often see that specified for non-metallic conduit runs. The idea is with a bare EGC, you should be able to clear a ground fault within the non-metallic raceway quicker than if you had installed an insulated EGC. Other than the non-metallic raceways, I don't think I have installed an bare EGCs.

Interesting. Never thought about that.

Does a bare ground wire cause abrasion problems for the insulation of the remaining wires, resulting from the wire pull?

 

[Pierre C Belarge]

Since the wording of 250.118 states EGCs can be bare, it would seem that insulation type is not important.

300.2(A) Voltage.
Wiring methods specified in Chapter 3 shall be used for 1000 volts, nominal, or less where not specifically limited in some other section of Chapter 3.


So, is a bare EGC rated at 1000 volts?

If yes, would the insulation type be important in regards to 1000 volt requirements?

 

[don_resqcapt19]

Interesting. Never thought about that.

Does a bare ground wire cause abrasion problems for the insulation of the remaining wires, resulting from the wire pull?

In my opinion the bare wire does not cause abrasion problems when the conductors are all pulled in at the same time. Pulling conductors one at a time or adding conductors later may result in abrasion issues.

 

[don_resqcapt19]

...
So, is a bare EGC rated at 1000 volts?
...

Why would a bare conductor have a voltage rating? I would think that the voltage rating would be a function of the insulation and not the actual conductor.

 

[Carultch]

Why would a bare conductor have a voltage rating? I would think that the voltage rating would be a function of the insulation and not the actual conductor.

You would be correct.

The metal is what gives a conductor/insulator system its ampacity. The non-metal is what gives a conductor/insulator system its ability to withstand voltage.

In the case of bare conductors, there is no solid non-metal, and thus no guarantee of voltage rating. Air is the insulator, and the separation from other bare conductors is what gives it its ability to withstand voltage.