I am in the process of selling a home and after the inspection, the buyer has requested that I:

"Have certified electrician replace over amped 100 amp breaker in garage electrical panel with correct amp breaker."

I do not know what the term "over amped" means. I am not an electrician, but I have worked in construction for a good portion of my life and have also done a fair amount of electrical work over the years.

The panel in question is in the garage and is powered off of a breaker in the main panel in the house. I am not currently at the house and did not note how large the breaker or the panel in the house is.

I will be taking care of the double and quad taped breakers by adding 6 additional breakers for a total of 12, 20 amp breakers.

Please see attached photos and thanks in advance!

 

Should have a real electrition look this one over.
What's that main breaker say?
That sure looks like a really small panel and the neutrals and grounds are not seperated.

 

The main breaker in this sub panel is a 100 amp Square D.

 

IF the breaker in the main (in the house) is 100 amp you don't have any problems with that. As Joe mentioned, since this is a subpanel, the grounds and neutrals must be on separate busses. You also need another ground to an electrode (ground rod). What size wire is that connected to the breaker?

 

"Overamped" probably means double tapped.

That's the one thing home inspectors look for. The last job I went on the "lady" home inspector made a big deal out of how dangerous double tapping a breaker is.

They don't know. It's technically wrong but it is not dangerous. The breaker will only deliver 20A and then trip. You could remove the two wires from the breaker, make a splice and add a tail. Now you have one wire in the breaker. Any safer.... nope. Code approved.... yes.

The breaker looks to be fed by #2 copper. It's printed on the jacket.

 

Even if the breaker in the main panel in the house is more or less than 100 amp, would it matter? Doesn't the main, 100 amp, breaker in the garage sub panel just act as a disconnect?

I can separate the grounds and neutrals and add ground rod. I don't know what size the wire is.

 

Each breakers in the garage breaker panel should be rated smaller than the feed breaker in the house. When an electrical fault occurs in the garage, you want the breaker in the garage to trip before the feed breaker in the house. This is called breaker coordination.
The breaker in the house feeding the garage should be rated based on the wire gauge from this breaker to the garage breaker panel.
Hope this helps.

 

The breaker in the main panel can not exceed the amp rating of the panel or the maximum amps for the cable connecting it.

 

The home inspector's use of that phrase says it all to me.

 

I'm pretty sure that "over amped" only means that the amperage of the breaker is too great for the circumstances.

My wire table gives 100 amps as okay for the #2 gauge wiring. You need to double check the garage panel rating (on a paper label) to be sure the entire panel is rated for 100 amps.

Sometimes coordinating the supra panel feed breaker and the subject panel top breaker is not practical. The feed from house panel to garage panel can only take 100 amps so the house panel breaker will be that. To coordinate the breakers the garage panel breaker has to be less (80 amps the next size downward?). You might not want that.

Also coordinating the breakers does not guarantee that the subpanel breaker will trip first. Some breakers may be faster acting than others.

 

In my opinion ThisOldMan has the best answer.

I DO have one question, is this garage detached from the main house? Different rules apply for attached and detached structures.

Home inspectors are generally NOT that well-versed in electrical codes and they often make mistakes by relying on "rules of thumb" when it comes to electrical installations. A prime example is what you have with the so-called "double tapped" circuit breakers. MOST circuit breakers are "listed" (by a nationally recognized testing laboratory, or NRTL,) for only a single wire to the CB. However, the Square D QO CB (which you have) are specifically listed for TWO conductors of the same size. That means that your installation with two wires per circuit breaker IS acceptable.

There is also a matter of when this installation was made. Several members have pointed out that you have both neutral and equipment grounding conductors on the neutral bus bars. IF this is in a detached structure AND was completed prior to about 2003, having a "three conductor feed" was acceptable provided that there were no other metallic connections between the building having the service (main) panel and the detached building. This means no metal water or sewer piping, no telephone wiring, no metallic data wiring or any kind of control wiring. It was not the preferred method but it WAS LEGAL under the National Electrical Code (NEC). I'm betting the only code violation, if any, is the lack of a "grounding electrode" also known as a ground rod, at the detached structure.
Further, any "sub-panel" (that term does not exist in the NEC) may have a "main breaker" of a larger amperage rating than the circuit breaker at the source (service panel) as long as it is not any larger than the amperage rating of the entire panel. That means that you could have a 200 ampere "sub-panel" in a detached garage being fed by a 30 ampere circuit breaker in the service panel and it would be legal. In truth, the ONLY time a main breaker is even required in a sub-panel is when the sub-panel is located in a detached structure AND there are provisions for more than 6 circuits in the sub-panel. If the sub-panel can only hold a maximum of four single circuit CBs and does not allow for "tandem" CBs then no main CB is required. If the sub-panel is located in an attached structure then no main CB is required no matter how many circuits can be added to the sub-panel.

One caveat: ALL codes are LOCAL. No national (model) code has any power of enforcement UNTIL that model code is adopted and enacted into law by a LOCAL or regional legislative body such as a city or county council or the state legislature. Note also that the enabling legislation has the power to add to or delete from the model code. Bottom line, ONLY the code that is enforced in YOUR jurisdiction has any bearing.

I would tell the buyer to have his inspector quote the applicable violations, chapter, section, paragraph, sup-paragraph, from the official electrical code enforced in your jurisdiction. My bet is that he/she can't do it because the so-called violations do not exist.

 

I think the panel was fed by something like a 60 in the main panel and the inspector thinks the wire is too small to feed the 100 amp breaker. If that is the case there really is no issue except lack of knowledge on the inspectors part. The 100 is now just means of disconnect.

 

Furd - It is an attached garage built in the 1990s. The panel is on the common wall.

What I’m understanding is that the most important thing is the breaker in the main panel in the house is the correct size for the wiring to the garage panel and the panel itself. The garage panel main breaker is really just an expensive disconnect. So, in theory, I could just remove the 100 amp breaker from the garage panel altogether and attach the feed wires direct.

Tomorrow I will check the garage panel rating and the size of the breaker in the house panel that supplies the garage.

 

Ignoring the feeder and separate grounding issues....

Those branch breakers may be listed for 2 wires but looks like 4 going to the upper left one.
Also - more than one white wire or three grounds per hole is generally a violation. Check what the panel label states.

 

Yes.No, there is no way to connect them plus code requires a disconnect if you have more than six circuits so if you ever added a circuit it would be required. Some argue the code means possible number of circuits not actual breakers installed so in that case the disconnect is already need because the box can have more than six circuits.

 

If the garage is attached as stated, there is no need for a disconnect or the 6 throw limit.

 

OOOPs, I forgot we were talking about an attached garage.

 

I went to the house today to work on the buyer's list of requests. The feeder breaker in the main house panel is 100 amp and the garage panel is rated for 100 amp. The individual 20 amp breakers are each designed to accept 2 wires, so the 6 breakers will cover all 12 wires.

The buyer's original requests:
My responses:

1. Square D QO circuit breakers are designed to accept 2 conductors of the same size. Wiring has been adjusted so only 2 wires run to each breaker.
2. The 100 amp main circuit breaker in the garage electrical panel is compliant and will not be replaced.

We'll wait and see if they have anything to say.

Thanks to everyone for all of your assistance!

 

Excellent reply. Keep us informed.

 

And all the confusion was created by a home inspector that doesn't know beans about electrical codes. He didn't even catch the most obvious problem of the neutrals and grounds being mixed on the neutral bus bars and made a huge issue of a non-issue.

 

You may be required to still bring in an electrician. I just ran across similar problems in two condos. Only a letter from an licensed electrician with his seal would suffice.

 

The main and branch breakers all look compliant to me too. The one area where you could improve this panel would be to break out the neutral wires to one-per-screw. Grounds of the same size can be tripled per screw. As others said, the three wire feed to the panel may or may not have been a legal method at the time of installation -- not enough information to know in this case.

One thought -- is that metal conduit continuous back to the main panel? If so, there's your fourth conductor. Continous metal conduit is a legal ground. To be fully compliant you would need to electrically isolate the neutral bar from the metal box, add a ground bar screwed directly into the metal box, and relocate the ground wires to the new ground bar.