Question for the welders-EMT versus rigid conduit

[Bluedog225]

I got to thinking about putting high-voltage direct current lines inside a house and enclosing them with EMT or rigid conduit.

My gut tells me that EMT could burn through at say 600 volts and 100 amps. But I don’t know that for a fact.

My gut also tells me that the same might not make it through rigid conduit. The heat capacity of that heavy pipe would absorb some energy.

I bet one of you welders has a better feel for this.

Either with a simple arc between conductors or an arc to the metal tube itself.

Anybody care to speculate?

 

[hwy17]

Let's not take any chances and just stick to mineral insulated copper clad.




But yeah I think rigid would for sure be better, until you see the price.

 

[Brucey]

I got to thinking about putting high-voltage direct current lines inside a house and enclosing them with EMT or rigid conduit.

My gut tells me that EMT could burn through at say 600 volts and 100 amps. But I don’t know that for a fact.

My gut also tells me that the same might not make it through rigid conduit. The heat capacity of that heavy pipe would absorb some energy.

I bet one of you welders has a better feel for this.

Either with a simple arc between conductors or an arc to the metal tube itself.

Anybody care to speculate?

You aren't going to be getting 600V and 100A at the same time, that would be 60kW. More than likely you'll be in the 500V range at maybe 10A? For a 100A SCC.

 

[Bluedog225]

Fair point. I was estimating a large array. Looks like I overshot.

 

[Bluedog225]

Let's not take any chances and just stick to mineral insulated copper clad.


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But yeah I think rigid would for sure be better, until you see the price.

I’ve got the rigid laying around from craigslist. But dang that wire’s going to be expensive.

 

[Brucey]

Fair point. I was estimating a large array. Looks like I overshot.

Well if you had a few arrays you'd be getting up there, say four 5-6kW strings.

I'm planning on 3" pipe from the outside threshold of the house and then vertical to a midnite mnpv6 combiner. I'm not too worried about 48V nominal cabling exposed from SCC to lynx power in etc, unlike the higher voltage pv wires. Now per NEC everything should be in conduit even the 48V stuff?