Need a little Help with main disconnect

Older Home (1954) looks like 100 amp on exterior.
Panel it rated for 125 amps.
Main Disconnect is 60 amp.

Are you asking or telling?
What are your concerns on this panel?
What do you want to know? Really!


Looks like some removed the old panel and installed a new panel. Since the service disconnect is 60 amps you have a 60 amp service. That 2-pole Main CB should have a clip, rivet, screw or other means to keep it in place since it’s back-fed. Not sure why they didn’t move the main up two slots to take some strain off of those conductors that were probably short.

The master has spoken!

Sorry Roy, I didn’t see your post as we posted at the same time. Had I seen It I would have waited for Terrill to respond to you questions. :sunglasses:

Thanks, that’s what I have 60 amp service. Always was told to go with the lowest determined amps.

Of course nothing was labeled

You now have your answer!

I have another concern. I’m not sure because it is hard to be sure from the photograph but it looks like both the black and the red wires from a multi-wire branch circuit are connected to the same busbar. That subjects the neutral of that circuit to the strong possibility of overloading because when both conductors are supplied from the same bus bar so that the voltage between them is 0 the neutral has to carry the sum of the two energized (hot) conductors current. If each of them is fed from a 20 ampere breaker the neutral can end up carrying 40 amperes. Believe me when I tell you that the 12 gauge neutral cannot do that without the insulation melting. The resultant fault may cause an arc that could kindle a fire. This is why the 2014 code requires that such circuits originate at adjacent breakers with a handle tie installed between the handles so that when you turn off one hot you also turn of the other. In modern panels each set of breakers left and right are supplied from the other busbar than either breakers above or below. If the 2 conductors are connected to 2 adjacent breakers on either side of the box there will be 240 volts between them and 120 volts from each conductor to ground. The result of that arrangement is that the neutral only has to carry the difference of the current flow between the 2 energized conductors. Even if one of the breakers opens on an overload or fault the maximum current on the shared neutral is only the same as the current flowing through the breaker that remained on. That holds the maximum load on the neutral to 20 amperes rather than 40.

Trace each red and black that comes from the same cable. Measure between the terminals of the two breakers. If the voltage is not twice the voltage between either terminal and ground the circuit is disarranged and can end up badly overloaded without either breaker tripping.

Tom Horne

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It is are to help someone when all they do is say they need help but don’t ask a question.

I don’t know what you are looking at but, if two circuits come off the same phase leg, that is NOT a multi wire branch circuit. A multi wire branch circuit is two circuits originating on opposite phase legs and sharing a grounded conductor.

Nice catch, Tom. It looks that way to me as well.

I have been wrong before and I will be wrong again but I don’t think I am wrong this time. Your description of the nature of a Multi-wire branch circuit jibes with the description in the US National Electric Code (NEC) viz…
Branch Circuit, Multiwire. A branch circuit that consists of two or more ungrounded conductors that have a voltage between them, and a grounded conductor that has equal voltage between it and each ungrounded conductor of the circuit and that is connected to the neutral or grounded conductor of the system.

So we don’t disagree on what a Multiwire Branch Circuit is supposed to be. Now if you look at the yellow jacketed three wire plus ground cable that enters the cabinet ~2/3rds of the way up the left hand wall of the cabinet and trace the red and the black wire from that cable You may conclude; as I obviously did; that the red wire is terminated on the bottom right breaker and the black wire is terminated on the bottom left breaker. With modern panels breakers that are directly opposite each other are connected to the same busbar. If I did not see it wrong the 2 energized conductors in that cable are connected to the same busbar so they do not have a voltage between them and yet they are in the same cable and share the same neutral. That means that a Multiwire Branch Circuit has been misinstalled or has been disarranged so as to make one neutral carry the sum of the current from 2 energized conductors each of which is terminated on a 20 ampere breaker. When a Multiwire Branch Circuit is disarranged in this manor the neutral may end up carrying up to the total amperes of current which is available from both breakers. A 12 gauge wire is not listed to carry that much current. The insulation on that neutral will melt and fail if it carries more than 25 amperes for any significant period of time. At 40 amperes of current that failure will not take long at all. Once those two energized conductors are loaded at a total between them of 30 Amperes or more a failure of the insulation is inevitable. As luck would have it that has not happened yet. But if it is left connected in that manor then it is only a matter of time before that neutral wire is damaged.

Another issue: 2 neutral conductors are terminated in the same terminal on the neutral busbar just to the left of breaker number 9; if you count by the usual numbering convention of odd numbers on the left side and even numbers on the right. That practice violates the listing of the panel and is specifically forbidden by the US NEC.
408.41 Grounded Conductor Terminations. Each grounded conductor shall terminate within the panelboard in an individual terminal that is not also used for another conductor.

I hope I was a little clearer this time. If anyone still sees a problem with what I have written please let us all know what that problem is.

Tom Horne

It does appear that the black and red conductors from the same cable terminate on the same phase leg which could potentially overload the neutral. This wouldn’t be a problem if the NM cable was 12-2-2 instead of 12-3.

“Work appears to have been performed without approvals or inspections. Have an electrician evaluate or if your state requires, an electrical inspector.”

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