[buddhakii]

I'm just starting a job and in the spec. it states to come out of the slab with pvc coated grc. But from there I have to use rigid aluminum. Is it o.k. to connect the two different metals together? It also says in the spec to keep the aluminum isolated from other metals with plastic sleeves or plastic coated hangers. What are your all thoughts?

 

[BBQ]

I would send out an RFI asking how they want you to do this.

 

[Chris1971]

We did a job where the specs stated the use of rigid conduit. We did a transition from PVC to aluminum. Not sure how you would transition from rigid to rigid aluminum?:001_huh:

 

[backstay]

I can see bonding as a problem if you isolate the two.

 

[ponyboy]

I would think the continuity of ground would supersede the engineers bright idea but that's just me

 

[BBQ]

I would think the continuity of ground would supersede the engineers bright idea but that's just me

I assume there will be a copper EGC in the conduit.

 

[ponyboy]

I assume there will be a copper EGC in the conduit.

True but would the two different conduits be allowed to be mechanically isolated per the NEC?

 

[Jlarson]

RFI coated Al rigid underground.

 

[ponyboy]

Also how does the run originate, what's in the ground?

 

[buddhakii]

Also how does the run originate, what's in the ground?

It will be pvc in the slab then transition a pvc coated rigid 90 out of the slab. Do they make pvc coated aluminum conduit?

 

[buddhakii]

Nevermind, just googled it and it looks like they do make it.

 

[hardworkingstiff]

I agree with your concerns.

What kind of project is it that they want you to use aluminum conduit?

 

[buddhakii]

I agree with your concerns.

What kind of project is it that they want you to use aluminum conduit?

It's a water pumping station. I use it quite a bit in water and waste water industry. Price is pretty comparable to grc but it's sucks to work with. Come home covered in black oil everyday.

 

[RIVETER]

I'm just starting a job and in the spec. it states to come out of the slab with pvc coated grc. But from there I have to use rigid aluminum. Is it o.k. to connect the two different metals together? It also says in the spec to keep the aluminum isolated from other metals with plastic sleeves or plastic coated hangers. What are your all thoughts?

The bare threads are now, not coated. The oxide on the surface of the aluminum will cause a reaction.

 

[bkmichael65]

As long as it's not in a corrosive environment, it will probably be okay to transition steel to aluminum. I wouldn't want to rely solely on the conduit for a ground path, though

 

[pudge565]

As long as it's not in a corrosive environment, it will probably be okay to transition steel to aluminum. I wouldn't want to rely solely on the conduit for a ground path, though

Read above, water treatment plant, gonna corrode.

 

[sparky970]

It will be pvc in the slab then transition a pvc coated rigid 90 out of the slab. Do they make pvc coated aluminum conduit?

Are you an electrician?

 

[Rns]

It's a water pumping station. I use it quite a bit in water and waste water industry. Price is pretty comparable to grc but it's sucks to work with. Come home covered in black oil everyday.

It's great to work with. Weighs almost nothing.... You're going to be oily anyways threading GRC all day

 

[Cow]

Are you an electrician?

No, he's just managed to make 322 posts without getting caught yet....

 

[buddhakii]

Are you an electrician?

You caught me. Never seen pvc coated aluminum which makes me just a handyman I should've known though because I have seen pvc coated stainless steel.