Wiring question in panel

The panel was not labeled.

There is one wire with a red and black connected two 2 breakers. It is located at the bottom right of the panel.

Can someone explain why this is wired this way.

The dryer & stove are gas.

Thanks

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Well…it could be either the IMFAMOUS multiwire circuit or a 240V load that they simply did not understand the concept of EITHER having to be on a properly TIED breaker.

If no other ACTUAL 240V loads in the house to speak of…then it is a multiwire circuit…and if so…read my explanation on THIS thread listed below

http://www.nachi.org/forum/showthread.php?t=13442

What is the amperage of the breakers. Looks like a multi-wire circuit or a 240 breaker with a missing handle tie. You would almost have to know what it goes to to make a determination if the breakers are 20 amp or 15 amp.

There 2 20 amp breakers. The basement was poorly finished. I had to dismantle half the wall to get to the panel. I left all the framing on the floor & told my client to have the framing removed as it is a violation of panel clearences. The home was vacant & I try to do my best to open the panel.

Was that the service equipment or a distribution panel. If it is a distribution panel, the grounds and neutrals need to be separated.

William,

Lets HOPE it is the Main Distribution Panel because not only that but the NICE large GREEN bonding screw in place would be a problem as well…lol

Yes it is the main distribution panel & I did call out the green bonding screw.

I have asked the question pertaining to this screw many times.

Correct me if I am wrong. The purpose of the bond screw is to direct any stray current to ground & not to the panel cover. For example if a hot wire was energizing the panel & someone touched the metal dead front cover then hopefully the current is directed to groungd & not the person in contact with the cover.

It seems there are many different ways that the bonding screw & strap are connected.

It seems like this is often not done correctly.

Thanks

No the green bonding screw needs to be installed when it is the main panel…only when it is a distribution panel is it removed.

[quote=dmacy]
Yes it is the main distribution panel & I did call out the green bonding screw./quote]

Allright guys, now I’m confused.
Paul, please clear up any confusion here.
Please bear with me.

?What would you need to call out if the panel pictured is the “Main Distribution PANEL” as I assume you mean it contains the Service Discontent?
The Green bonding screw is as it should be and I also see the strap tyeing the neutral and ground bus together.

I am sorry that I am confused & confusing you.

The panel pictured is the main panel. It is not a sub panel.

Sorry

Then why would you “call out” the green screw?

The bonding screw in the picture grounds the neutral buss to the main service panel housing, so that if it became energized it would not shock you…it would have a path to ground.

The difference is in the distribution panels (sub panels) that have isolated ground and neutrals. Removal of the bonding screw is important to keep the neutral and grounds seperate.

Paul can probably explain it better, but that is my best.

Yes, that is exactly my understanding.

David said he “called out” the green screw.
Perhaps he only means that he called out its presence and not that it was a defect.

David,

NO…what I was saying in response to Williams question…not your post. He was asking IF it was a Sub-Panel so to speak and if to the G & N should be separated…I was saying if it TRULY was ( which I do not think it is ) a SUB-PANEL then that GREEEEENNNN screw would need to be removed also.

On the STRAY thing…ahh…not really…lol…the excessive voltage or fault current is making its way BACK to the panel and to the source which is at the transformer…but you have the concept in that the bonding jumper is NEEDED to complete the path…

So in this case…it is VERY needed if this is a main distribution panel.

lol…HE DID NOT call out the green screw I hope…Sorry I was on the phone with a customer when I was replying…read my post please

Man you guys are FAST…I had to stop and answer a emergency electrical problem for a local person…I talked this 30 year old lady with a 3 year old how to FIX her GFCI while on the phone…priceless…:slight_smile:

Is the green bonding screw making contact with the panel enclosure or is a strap needed?

Some times there is a strap.

Sorry about the fuzzy picture. That is how my head feels.

There is some serious snow & drifting going on. Between inspecting & shoveling/blowing I am worn out.

My client asked me yesterday what the roof looked like. I told her it looks like a ski slope.

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If this is a PROPER bonding screw ( which it looks like it is ) it is making contact with the panel through tapped and threaded screw holes thru the bar and into the panel enclosure itself and is considered the bond.

Some panels do this with a Bonding Screw, Bonding Strap and the Bonding “Z” bar many of you see…all are considered effective.

Both are needed as long as this panel contains the Service Disconnect.

Michael,

If you are talking about the small " Z" connection that connects the grounded/grounding bar to the metal enclosure…only (1) is needed. If there is no connection BETWEEN multiple buss bars then they would need to be connected together…which would simply be multiple bonding jumpers…technically speaking…but if the two buss bars are connected let say with a drop under bar or through a built in mechanical connection then only one bonding jumper would be required.

In this case…notice the BONDING BAR under the panel…that makes the connection to the other buss bar so only (1) Bonding to the case method is needed.

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