Double Main Panels

[stubrooks]

Has anyone seen something like this? Two sets of SEC are brought in from a single 200 Amp Service meter box connection (1 meter). Each SEC is connected to separate 200 Amp size main panel mounted side by side. Each panel is wired as a Master. I've not seen or heard of this before. A master and a subpanel yes, but not dual masters.

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[Jim Katen]

Originally posted by stubrooks

Has anyone seen something like this? Two sets of SEC are brought in from a single 200 Amp Service meter box connection (1 meter). Each SEC is connected to separate 200 Amp size main panel mounted side by side. Each panel is wired as a Master. I've not seen otr heard of this before. A master and a subpanel yes, but not dual masters.

I see these frequently. There's nothing wrong with the concept.

There are some other problems with those panels though. Do you have pictures that show more detail?

- Jim Katen, Oregon

[John Dirks Jr]

Is it ok for the unused portions of those busbars to be exposed like they are?

I see a white hot that looks like it may not be marked. Make that a few unmarked white hots

[Neal Lewis]

Originally posted by AHI

Is it ok for the unused portions of those busbars to be exposed like they are?

[?][?]

John, they're not exposed. And neither are the main lugs, once the cover is on...

[John Dirks Jr]

Originally posted by Neal Lewis

Originally posted by AHI

Is it ok for the unused portions of those busbars to be exposed like they are?

[?][?]

John, they're not exposed. And neither are the main lugs, once the cover is on...

I thought about that before posting Neal. BTW, where is the cover in the picture? How can you say there is no exposure when you can't see if the knockouts in the cover are done correctly for this setup. I still think there is something not right about the busbars being exposed, cover or not.

Another thing, I don't remember seeing so many branch wires exiting a panel in one location like they do in that photo. Can someone explain that?

[jon_ran]

Keep in mind that the main cable from the supply to the meter and the meter iself should be capable of carrying the current capacity of the panels. If both panel;s are rated at 200 amps with a 200 amp feed you could be looking for trouble.

BTW, Some of the new meters do have lugs to allow 2 sets of cables to go to 2 separate panels.

[stubrooks]

Answers to some questions:

1. The panel covers do cover the exposed bus areas. All breaker slot fillers are in place. I didn't take a picture of the covers.

2. Yes, there are too many wires in a panel entry hole, in several places.

3. Yes, there are unmarked white or neutral wires connected to breakers.

4. More than one ground or neutral inserted into a single bus bar hole - multiple places. There was no need to do so because there are lots of empty connection points.

Advised client to have a licensed electrian to review panels and repair wiring. And not to call the same licensed electrician who installed it.

It is all too common in this neck of the woods for any ding-a-ling who pulls wire for a week to call himself an electrican and setup shop

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[homnspector]

Are those service equipment or are they sub panels? It looks to me like they are sub panels and should have neutrals and grounds separated. When I have seen these, there are main breakers outside at the meter.

[Jerry Simon]

I believe the unmarked white hots are okay. They're for 240-volt circuits and are in non-metallic sheathed cable wiring.

Aside from the other problems, this is an often-seen 400-ampere service. Meterbox-type outside should tell.

[msteger]

Were these dual panels to feed one home/structure with dual living areas or a storefront and residential space? Since you mention there is only one meter, I would guess it wasn't two separate living areas (like rentals).

Not sure why they'd have two panels when each is only partially populated (each appears to be slightly half full). Generally, I'll see one full main panel and then an auxiliary (sub) panel installed feeding off the main panel. If the only service disconnects to be found are the two MAIN's in each panel, then I could considered both of these as 'main panels', but indeed weird, at least in my neck of the woods. Since you are in VA, I would assume they don't put the main service disconnect outside (like they do out west) and then feed the panel(s) on the home's interior.

I have seen a few 400 Amp/240 Volt services in my time, but there is normally a large metal distribution box that feeds each panel.

I would also recommend evaluation by a licensed electrician as well as determining if the service cable from the street to the meter is capable of supplying these two panels safely.

[Jesse]

Originally posted by msteger

I would also recommend evaluation by a licensed electrician as well as determining if the service cable from the street to the meter is capable of supplying these two panels safely.

An electrician has nothing to do with the service drop. That's the domain of the power company. They dictate their own rules.

[Jim Katen]

Originally posted by AHI

Is it ok for the unused portions of those busbars to be exposed like they are?

Yes. It's fine. The deadfront is intended to protect them. There's no requirement to have the buses covered with the deadfront off.

I see a white hot that looks like it may not be marked. Make that a few unmarked white hots.

The white wires are supposed to be marked. A quick swipe from a Sharpie is adequate. Personally, I don't report on this issue.

- Jim Katen, Oregon

[Richard Moore]

"Personally, I don't report on this issue."...

Me neither. My feeling is that a white hot wire in a panel is adequately identified by being connected to a (normal) breaker's terminals. In fact I consider it "permanent" identification. Remove the wire and, well, it's no longer hot!

Frankly, I can't remember the last time I actually saw a hot white marked at the panel. It sure doesn't seem to be the custom around here.

Now...if I saw an unmarked white away from the panel, say in a junction box or as a feed to a sub, that I knew was hot, then different story. THAT, I would consider a reportable safety hazard.

[charlieb]

The white wires are supposed to be marked. A quick swipe from a Sharpie is adequate. Personally, I don't report on this issue.

Jim,

Is there not some verbage that states under a specific guage white is not allowed?

By the way, I don't write it up as part of a HI.

[Jim Katen]

Originally posted by charlieb

Jim,

Is there not some verbage that states under a specific guage white is not allowed?

By the way, I don't write it up as part of a HI.

Not that I'm aware of.

If you're using a cable such as Romex, you can use the white wire as an ungrounded conductor if you re-identify it.

If you're pulling wire through conduit, you can't use white wire as an ungrounded conductor at all. You're expected to drag your butt out to the truck and get a reel of properly colored wire.

- Jim Katen, Oregon

[Jim Katen]

Originally posted by Jesse

Originally posted by msteger

I would also recommend evaluation by a licensed electrician as well as determining if the service cable from the street to the meter is capable of supplying these two panels safely.

An electrician has nothing to do with the service drop. That's the domain of the power company. They dictate their own rules.

Very true. In general, the power company doesn't give a rip about how many 200-amp panels you've got. They're interested in the load calculation for the whole house. If the load calc shows that the house only want's to draw 125 amps, that's what they're going to use to size the drop.

- Jim Katen, Oregon

[homnspector]

Surprised nobody mentioned the doorbell transformer in the left cabinet.

[Jim Katen]

Originally posted by homnspector

Surprised nobody mentioned the doorbell transformer in the left cabinet.

I was wondering if it was actually hooked up to anything or just lying there. For the record, it should be mounted outside the cabinet, not inside.

- Jim Katen, Oregon