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Multi Meter Service
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Joined: Jun 2003
Posts: 1,143
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DougW Offline OP
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OK - I've done several "panel swaps", where I replaced fuse boxes for breaker panels; I've also changed out single drop services.

I've never had to re-do an outside service drop for a multiple family dwelling, so this is partly a lack of experience admission.

I removed the old (1 1/4") RMC and double meter box, and replaced it with 2" EMT to the first meter - two separate single-meter boxes nippled together. I then branched off into the units, following the original run paths, ones runs from each meter to each unit's new breaker panel.

The AHJ just bounced my install. I missed the section in the Commonwealth Edison handbook about bussed meters [Linked Image] -

Quote
(6.33) In the case of multiple-position or grouped meter connection devices, conductors or bus from the source of supply shall be continuous to the last meter connection device and connected to the meter connection device terminals in accordance with the Company's requirements.

(6.34) Metered load conductors shall not pass through adjacent meter connection devices unless such conductors are properly
barriered from the unmetered conductors and are an integral part of an approved prewired multiple-position meter socket assembly.

"My bad" as they say in the hood.

Then the AHJ tells me that the entrance riser has to be GRC. The only ComEd ref. I can find that requires rigid is the following:

Quote
® Service run.
Rigid conduit must be used if the service run is extended through the roof.

Since the riser is supported on the wall, and doesn't penetrate the roof (not a mast), isn't EMT allowable?

The AHJ went on to tell me that EMT isn't allowed as a riser in the NEC... but in the '96 Code (which our city follows), there's the following:

Quote
230.45 Wiring Methods for 600 Volts, Nominal, or Less

Service-entrance conductors shall be installed in accordance with the applicable requirements of this Code covering the types of wiring methods used and limited to the following methods: (1) open wiring on insulators; (2) Type IGS cable; (3)rigid metal conduit; (4)intermediate Metal Conduit; (5) [u]electrical metallic tubing[u]...

I can understand the requirements for RMC as a riser, but if it's supported?

Just venting before I go out and buy more materials for this job...

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Joined: Jan 2004
Posts: 105
C
Member
Hi Doug- tough one there, I'm in n.IL too and we've always had to use rmc for the riser- I was trying to find that in writing somewhere, but can't. So it was either Al or steel, but always threaded rigid, EMT isn't raintight vertically, and if you had to use a no-thread, it had to be on down side of coupling(threaded)- so you would thread into hub, and put weatherhead on the other cut end, or if higher than 10', then put the merchant coupling on the bottom of the top piece and the no-thread on the top of the bottom piece. And it is for sure about the continuous feeder through to the last socket. And to have to redo with all the rain!! Uff-da. good luck.

Joined: May 2004
Posts: 697
D
Member
I've always used RMC all the way to the distibution panel, Doug. I call the service "Un-fused ComEd". Even though it is fused, if the wires were damaged it would probably shoot fire until they came out and disconnected. With their overload of work these days, that could be awhile.

I feel for you, buddy. Some days it just doesn't pay to get out of bed, and as chi spark said, don't you just love this ongoing drizzle?

Dave

Joined: Feb 2003
Posts: 169
R
Member
Chicago code is the only one that I know of that doesn't allow EMT.

(on the line side of the main)

[This message has been edited by russ m (edited 11-19-2004).]

Joined: Feb 2001
Posts: 159
C
CRW Offline
Member
So what the Com-Ed rule is saying about your ganged up meters is that the nipple is no good; that you need a real factory 2-gang meter base?

I've never seen an EMT service anywhere, although out here in PA PVC services are common for apartment buildings. Never saw that in Chicago! Don't remember about the Com-Ed book, but in Chicago we had to put all rigid threaded pipe, aluminum or galvanized steel, up to the disconnect or main panel. Even the nipple between the meter and the panel, through the outside wall. Once I had to take apart a newly energized service and replace a 2" EMT nipple, 12" or less long which was back to back from a meter pedestal into the back of a main 200A panel. Com-Ed had pulled in and energized the underground lateral before the city inspector had seen it, and we had temp lights and receptacles running off the new panel already. The inspector failed it and we had to change the nipple. Stupidly, we did it with the meter pedestal still hot, and wouldn't you know, it started raining too!

Joined: Apr 2001
Posts: 518
J
Member
What your AHJ wants is similar to what we do in Reno.
When I have a feed to several meters, I use a gutter above them.
I never considered using EMT; apart from local code requiring RMC/IMT, it neve made sense to me to run EMT to a panel or myers' hub. If nothing else, a compression fitting atop a hub looks awkward to me.

Now- for those who never run rigid- I reccomend a cheap pipe die, for cleaning the excess zinc off of the threads.

Joined: Feb 2003
Posts: 687
A
Member
Hey Doug,

Sorry to hear about the trouble. I can't think of a reasonable way to make the supply continous with out a factory multi meter bank. The Com Ed diagram just says typical with the multi gang meter. Not saying you could not do it another way if you can comply. If you have the basic 200 amp overhead meter socket they don't have much wire bending space as it is.

As for having to be ridgid I could not find anything saying it had to be ridgid if is is not supporting the drop. I'm not saying it not there. It can be a local Requirement. It just seems to be the way everyone does it. I take the GRC into the panel because some places require it and others don't have a written requirement but expect it.

You did not say what town it is. It sounds strange the the village inspector is enforcing Com Ed rules. Unless the village adopted Com Eds requirements I don't think they have a right to bounce you for a utility requirement. If it does not meet the utility standards they can't bounce you for it.

Sometimes you get a village that does not have much for a building department has not much for codes or amendments. They still expect it to be the same as every other place in the area. Maybe the inspector knows it would meet NEC standards and the village has nothing on paper saying what they want so he is bouncing it for utility requirements.

I'm not saying not to change anything. I'm just saying it probibly looked different from the way eveyone elce does it so it got taged. Right or wrong it does not allways pay to be different.

Let me know if you need to borrow a threader.

Tom

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Joined: Jun 2003
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DougW Offline OP
Member
Thanks for all the feedback, guys. Looks like I'll be puttin' the new rig up... once/if it stops raining.

The important thing is the HO has power for now, and at least that was the only potentially "unusual" aspect of the install.

I'll let you know how it goes.

Joined: Apr 2003
Posts: 362
Member
I don't think there are any fitting rated for EMT that are UL approved for wet locations. The compression type fitting are no longer suitable.

Phil


Choose your customers, don't let them choose you.
Joined: Feb 2003
Posts: 169
R
Member
There are several brands of conduit fittings with the (new) rain-tight listing.

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