Metallic conduit GEC

[hhsting]

If I have metallic conduit non ferrous that bas grounding electrode conductor to main service grounding electrode system then I have to bond the metallic conduit to the grounding electrode conductor?

 

[infinity]

No. Non-ferrous metal raceways such as aluminum do not require bonding.

 

[tom baker]

Al is a good choice andif it is bonded at each end the large surface area and OD greatly reduces the impedance. But PVC is the most practical if physical protection is needed
Source: IEEE Green Book,

 

[hhsting]

No. Non-ferrous metal raceways such as aluminum do not require bonding.

Is EMT. IMT or RMC considered ferrous?

 

[Dsg319]

Is EMT. IMT or RMC considered ferrous?

Yes

 

[infinity]

Is EMT. IMT or RMC considered ferrous?

Yes and some stainless steel can be ferrous also. Aluminum is guaranteed to be non-ferrous.

 

[suemarkp]

I wouldn't say RMC is considered ferrous, as it is available in different metals (steel, aluminum, stainless steel). It depends on which metal you pick. IMC may also be available in these metals. Not sure if EMT is ever anything but steel, but I would not assume a given metallic conduit is steel.

 

[infinity]

I wouldn't say RMC is considered ferrous, as it is available in different metals (steel, aluminum, stainless steel). It depends on which metal you pick. IMC may also be available in these metals. Not sure if EMT is ever anything but steel, but I would not assume a given metallic conduit is steel.

EMT comes in both steel and aluminum so like RMC it can be either ferrous or non-ferrous.

 

[tom baker]

I wouldn't say RMC is considered ferrous, as it is available in different metals (steel, aluminum, stainless steel). It depends on which metal you pick. IMC may also be available in these metals. Not sure if EMT is ever anything but steel, but I would not assume a given metallic conduit is steel.

I have seen AL EMT advertised, but don’t know about availability. And are the fittings AL or steel?

 

[wwhitney]

And are the fittings AL or steel?

For better or worse, 250.64(E) refers to "Ferrous metal raceways, enclosures, and cable armor." So does it matter for code compliance if the fittings are ferrous or not?

Would a single ferrous fitting that encircles the GEC cause a significant impedance increase at lightning frequencies?

Cheers, Wane