Is it okay to use a tandem breaker in this service panel? It is supplying a 100-amp apartment.

1-20 amp Bath
2-20 amp small appliance circuit 1
3-20 amp small appliance circuit 2
4-15 amp Lights/Receps
5-20 amp lights/receps

Circuit 5 will be upgraded to an AFCI breaker if that matters.

Sure, no problem adding a tandem breaker to this panel, I believe this panel can handle six tandem breakers.

However, may I list a few observations of other problems/violations I see?

The Main Breaker is clearly a 100 Amp breaker, and the incoming wires, and the subfeed wires off the subfeed lugs do not appear to be 100 Amp rated.

The Main incoming wires are only clamped by the connector, and are not in any raceway(conduit).

Main neutral is not combined with the incoming hot wires.( Must be combined to prevent induction heating effect caused by the magnetic flux of AC current.)

The top and right connectors appear to be for Service Entrance Conductors, (The top must be if they are feeding a Main breaker) and even thou one has a bonding bushing, neither are bonded correctly.

The Neutral lug on the right has two wires in a lug only rated for one wire.

Since the Main breaker is in this panel, the Neutral bar should be bonded to metal box, I do not see a Main Bonding screw or jumper.

The Romex cable at bottom left is missing a connector.

The MC cable at the bottom right is missing an Anti-Short Bushing (AKA Redhead).

The bit of utility meter I see at the bottom tells me that his building is a multi-family dwelling (apartment), should check to determine if non-licensed or permits are not required in that town, city, county, state.

Clearly, by the violations I found in one picture, tells me that a un-qualified person did that work.

Thanks for the feedback. The last owner/maintenance person clearly did not wire this properly. As it is a multi-family I am not doing the wiring myself. I am in the process of determining exactly what needs to be done and will then hired a licensed electrician.

Could you tell me what gauge the main wires are and what gauge would be rated for 100 amps?

#3 THHN copper or #2 XHHW aluminum

Sorry I misread your last question:




Could you tell me what gauge the main wires are and what gauge would be rated for 100 amps?


When I gave #3 copper and # 2 aluminum, I meant these are the 100 amp rated wires.

The existing wires appear to be #6.

Is it okay to use a tandem breaker in this service panel? It is supplying a 100-amp apartment.

1-20 amp Bath
2-20 amp small appliance circuit 1
3-20 amp small appliance circuit 2
4-15 amp Lights/Receps
5-20 amp lights/receps

Circuit 5 will be upgraded to an AFCI breaker if that matters.
That panel is against the NEC.If that is a subpanel you will have to take those grounds off the neutral bare and put a ground bar in mounted straight the inside of the panel.Yes tandems are OK

Why is this panel against the NEC? It is not a subpanel it is a service panel for an apartment. Assuming the violations that tkrussell mentioned are taken care of it still will not comply with the NEC?

As far as I am concerned it is fine to use. I am not sure what dei2007 means by "That panel is against the NEC.", besides what I have mentioned.

Oh, one thing I omitted from my list, the Main breaker will need a Retaining kit, your electrician should know what I mean and why.

Why is this panel against the NEC? It is not a subpanel it is a service panel for an apartment. Assuming the violations that tkrussell mentioned are taken care of it still will not comply with the NEC?

You probably have a main panel outside where all your 240 volt stuff is fed from.Then your inside panel is considered a subpanel, then in return your grounds have to be separated from the neutral bar.

Die if you look close below the panel, there is meter for another apartment, and Ohio admits this is a multifamily dwelling, and there is a breaker labeled 'MAIN", therefore this is not a subpanel, which if it was, you are exactly correct about separating grounds from neutral, but this appears to be not applicable.

Very seldom is there a Main Switch upstream of metering such as this type and age.

Otherwise, I would have mentioned it.

And what concerned Ohio is your statement that the panel itself was not code compliant.

The best thing he said was he will be having an electrician make any necessary repairs or changes.

The bset method of offering advice is to only offer defintite advice about a condition that is definite, otherwise, offer advice conditional on a possibility of a condition.