Aluminum weatherheads on steel conduit

[dcollinsrn]

Installing a 400 amp drop in 3" steel conduit - but it seems all the 3" weatherhead are aluminum.
Is the a safe way to use an aluminum weatherhead with steel conduit?
Is it a matter of using antiseize?

 

[letgomywago]

I've never seen it be an issue I used aluminum and pvc weather heads on GRC and never saw any issues. In fact the only ones I've never been able to remove are the 75 year old steel or cast iron ones that they used on 1 1/4 old 100 amp services.

 

[infinity]

Are they really aluminum? I always thought that they were an alloy similar to that used on die cast fittings.

 

[kwired]

Are they really aluminum? I always thought that they were an alloy similar to that used on die cast fittings.

Zinc die cast maybe?

 

[infinity]

Could be aluminum. I did a random search of two threaded weatherheads and both said that they were made of aluminum.

 

[roger]

It is specifically allowed in 342.14, 344.14, and as an exception in 358.12

 

[Dennis Alwon]

I've never seen it be an issue I used aluminum and pvc weather heads on GRC and never saw any issues. In fact the only ones I've never been able to remove are the 75 year old steel or cast iron ones that they used on 1 1/4 old 100 amp services.

I think the real issue is PVC conduit with a metal weatherhead. The weatherhead would need to be grounded.

 

[infinity]

I think the real issue is PVC conduit with a metal weatherhead. The weatherhead would need to be grounded.

I thought that too but what about a metallic weatherhead on SE cable?

 

[garbo]

I thought that too but what about a metallic weatherhead on SE cable?

Only reasoning that my old mind can come to is being the metal weather head is outdoors and too high for a person to come in contact with risk of an electrical shock is very low. Never came across a weather head that was energised. Was scary cutting out some old 30 amp services high off the ground that had cracked rubber insulation. Would cut both wires close to utility splice but some times old rusted 1/2" conduit was higher then utility point of attachment. Not a big fan of plastic weather heads. The day before I would do a 100 or 200 amp service liked to make up the weather head with 3' of wire hanging out and two layers of white tape on the grounded conductor and silicone the top hood on so it could not fall off. I would start maybe an inch below where the wires left SE jacket so cable clamp tightened down on a few layers of tape.

 

[CoolWill]

I thought that too but what about a metallic weatherhead on SE cable?

There was a time that lights above a certain height weren't required to be grounded. But you could sell 33% more wire if they are grounded, so the code changed to require them to be grounded. The manufacturers haven't found a way to make money by requiring the weather head be grounded. Yet.

 

[dcollinsrn]

It is specifically allowed in 342.14, 344.14, and as an exception in 358.12

Thank you!!!

 

[Dennis Alwon]

I thought that too but what about a metallic weatherhead on SE cable?

I think it is ridiculous but IMO, it would fail in some areas. I can see someone on a ladder who touches the bare neutral and the metal weatherhead where there was a short in it. How unlikely that would be....

 

[infinity]

I think it is ridiculous but IMO, it would fail in some areas. I can see someone on a ladder who touches the bare neutral and the metal weatherhead where there was a short in it. How unlikely that would be....

I think that with a really old service it would be possible for the dried out, cracked ungrounded conductor to actually touch the metallic weatherhead.

 

[Eddie702]

Don't give the code writers the idea. I can see it now. The metal clamp on a PVC weather head for SE cable will have a lug on it to attach to the neutral.

 

[kwired]

Only reasoning that my old mind can come to is being the metal weather head is outdoors and too high for a person to come in contact with risk of an electrical shock is very low. Never came across a weather head that was energised. Was scary cutting out some old 30 amp services high off the ground that had cracked rubber insulation. Would cut both wires close to utility splice but some times old rusted 1/2" conduit was higher then utility point of attachment. Not a big fan of plastic weather heads. The day before I would do a 100 or 200 amp service liked to make up the weather head with 3' of wire hanging out and two layers of white tape on the grounded conductor and silicone the top hood on so it could not fall off. I would start maybe an inch below where the wires left SE jacket so cable clamp tightened down on a few layers of tape.

That is my thoughts for this as well as a metallic head on PVC raceway.

Other sections of NEC basically don't allow the open conductors that leave the weather head to be at levels that are easily reached to begin with so the weatherhead is always above certain level anyway.

Lighting on wood poles that is maintained by POCO's almost never has grounding conductors. But also is up and away from people and IMO is not really a hazard. Many don't have any overcurrent protection either. Yet if I were installing them technically NEC still would require an EGC and overcurrent protection. I'll admit to installing many on farms over the years and connecting to overhead distribution with no EGC or overcurrent protection. Was doing that way before even giving much thought to whether they needed EGC or OCP. If we made a drop to a switch on the pole or even a switch in a building controlling the light then there at least was going to be OCP involved.