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Posted By: Joe Tedesco Was this encasement really necessary? - 07/12/04 10:03 PM
Was this encasement really necessary?

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Posted By: iwire Re: Was this encasement really necessary? - 07/12/04 10:16 PM
IMO overkill for this short distance, but given the wording of the NEC I believe the inspector can require this.

I have done this to get about 40' to 60' inside of buildings.

Bob

FWIW I hope there are some dowels into the foundation to carry the weight of this. [Linked Image]
Posted By: electure Re: Was this encasement really necessary? - 07/13/04 12:24 AM
Does this make it "outside the building"?
Looks like it meets 230.6(2)from here. Cant tell if it is 2" all the way around though.
Posted By: PCBelarge Re: Was this encasement really necessary? - 07/13/04 02:34 AM
Picture a 15 inch soffit overhang for the roof of a house. Now picture the RMC raceway for a mast run up the side of the house and throught the soffit and in the void up through the roof. There was about 15 inches of RMC in the space. The inspector made the contractor incase that portion in 2 inches of concrete, as he said it was inside the house....HMMMM

Pierre
Posted By: e57 Re: Was this encasement really necessary? - 07/13/04 03:40 AM
Now picture this... A guy shows up to do demo for a remodel. Sees a 6"X6" concrete column (somewhere outside of this panel room) and thinks to himself... Well it's non-structural, what's it for... Jackhammer, or Diamond saw? Boom!

If it were just the conduit, they would call an Electrician, right?

Just so happens, I had to call the Inspector for 230.70A today, we get a different answer everytime! Today, they said they'll get back to me... I have a job where we'll need to go 38' into the building.
The picture also seems to me to be overkill. Is this the only portion in the building? Is the other side of that wall outdoors or another part of the building that the pipe goes through?
E57 I don't see how there could even be a question for 38' inside the building.
Posted By: e57 Re: Was this encasement really necessary? - 07/14/04 06:35 AM
No other place to enter building, no other place for service, 38' to get there... (22' back 16' down, all service drops)

Cusomer is building the Taj Mahal, no kidding turrets and onion domes. Boss wants exposed, customer is taking a hissy fit about a 2" pipe running all over his palace. We'll let the inspector make the call...

230.70A is left pretty much up to the inspector.

Personal thought its that it needs to be clarified!

In the past they've OK'ed it! Sometimes they don't... I'm still pushing for under-ground from the pole. But PG&E takes about 18 months to connect! The Inspector hasn't called me back yet. Let you know what he says...

[This message has been edited by e57 (edited 07-14-2004).]
Posted By: iwire Re: Was this encasement really necessary? - 07/14/04 08:51 AM
E, I can not imagine going 38' into the building without encasement. There is no chance that would be allowed here.

As far as demo guys cutting into it that can always be a problem.

I had to help repair a 4" conduit that was cut by a concrete saw, it was one of eight sets of 600 kcmils that feed a 3000 amp 480 switch gear.

The operator of the saw was OK but it knocked out a neighborhood.
Dumb question from someone not privy to the sausage-making, err, code-making process: What's the point of the encasement? I can't see how RMC by itself would be measurably less safe than RMC encased in concrete. In theory, sure, anything in 2" of concrete is more protected than the same thing without the concrete. But, in practice, RMC is practically indestructible, absent a structural collapse or vehicle impact.
Posted By: classicsat Re: Was this encasement really necessary? - 07/14/04 05:38 PM
I think it is to protect the inside of the building in the event of a fault in the feeder.
Posted By: iwire Re: Was this encasement really necessary? - 07/14/04 08:27 PM
As indestructible as RMC seems it can be eaten up quickly (vaporized) by service conductors faulting inside it.

When I weld I can cut holes through metal as thick as RMC with under 125 amps.

Service conductor may have 1000s of available amps, it is possible that even 2" encasement is not enough.

Don R (A moderator here) got to watch RMC burn back quite a way when service conductors faulted inside.

Bob
Posted By: e57 Re: Was this encasement really necessary? - 07/15/04 07:18 AM
iwire, today they're calling it 30'! I get a different answer every time! We have gotten ok'ed at 40, depends on the mood in the air. After all other options are exhausted.

So yeah, it's back to the drawing bourd for the "Designer" who is making his big move toward archetecture. He now needs an engineer to devise as way to power it. They'll have to remove steel to allow a shorter path. Or, re-engineer to hold encasement. Or, the bite the bullet and we do it my way and underground we go... This requires two retaining walls removed, re enginneered, and replaced. The owner is going to flip out!
e57,

Some of these underground contractors have gear where they can drill a bore sideways, underneath stuff like retaining walls.

My impression is that, in general, it's cheaper to use these direction drills than it is to tear up and replace concrete. I've seen them use these machines to drill under the sidewalk to install fiber, and, in another case, to drill under the street to replace a water-service lateral.

That might work for your situation. (I don't have pointers to any contractors. The machine I saw drilling to install the fiber was made by Ditch Witch, if that's of any help.)

[This message has been edited by SolarPowered (edited 07-15-2004).]
Posted By: e57 Re: Was this encasement really necessary? - 07/16/04 03:07 AM
Yeah those directional drilling rigs are hip. Unfortunately due to the grade, (super steap!) not advisable. And, the walls need to be done eventually. Don't think they'll hold a rig like that! Just don't think they were planning to do it now.

Did a walk thru with the designer/arch... It went like this...

Can we put there? NO!
There? NO!
There? NO!

He just didn't understand workspace, or the ten other codes guiding entry and service location.
E, if it were me I would tell them I have to follow code. No exception. Give them the code compliant options, disconnect here, or here, pick one. Even if the inspector said go ahead and run 30' through the building with no overcurrent protection there is no way in hell I would do it.
Posted By: e57 Re: Was this encasement really necessary? - 07/17/04 12:15 AM
Yeah, I'm not into it either...

Unfortunatley, the building has to get fed somehow. It's not ever a question of where it will go at this point. It all comes down to a design without fore-thought as how it would function. And, I get to make it work, being caught in the middle of the Arch, and Inspector. My loyalty to the later! The only reason I even call about items like this, is for CYA purposes.

The inspector called it at 30', so over-head is out. I needed 38' for that. So under-ground we go.

As for following the code, I don't vary, and won't let anyone else lead me to. That is something I am very aggressive about. (something that gets me in trouble sometimes, but I don't care.) As by the end of this, the Arch will have a $50K past buget edjucation about where, and how services are done. The next one will be built around the service...
Posted By: e57 Re: Was this encasement really necessary? - 08/05/04 02:32 AM
Up-date on that job...
They found someone to do it! (38' through the building) And the rest of the job at half the price too!

Good riddin's!
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