Household wiring question

[Tube60]

Hi all
I've been doing a lot of work on the house lately, and one thing I've not paid attention to much is the wiring. I've always known that there are no GFI outlets in the bathrooms, so I went to the main panel, and sure enough, there's a GFI breaker there for the bathrooms, and it works. However in looking at the rest of the panel, I found something potentially scary: ALL the outlets in the house, garage included, are wired to a SINGLE 100 amp breaker. I don't know if this was legal in 1978, when the house was built. I recall at my old house, built in 1964, had a lot more breakers. However there are two 240v breakers, one for the stove and one for the laundry. I can just imagine getting a Sunfire H.T. subwoofer, or some such device, something catastrophically bad happens, and my house burns to the ground while the breaker happily feeds whatever's going on downstream!
So any advice from those familiar would be greatly appreciated!
Best regards,
Ross

 

[GregLett]

That is not normal at all for a house! It's wired more like an old apartment.
Even apartments these have a few different circuits. You need to get an electrician in there.

 

[MotorToad]

Can you take the cover off the panel and snap a couple of pictures? Ordinarily this is a 100% safe procedure, but I'd power it down just in case here since there's evidence we might be dealing with a dumbass wire monkey. What I'm concerned about is if this is an easy fix (the outlets are run in groups of 2-3 rooms to the panel) or if you're screwed (there's one wire in the panel that feeds all the outlets). I can't think in a million years that a single 100 amp breaker was to code in 1978, but that doesn't always stop things like that from happening and it doesn't at all stop an idiot from doing stupid things while rewiring a house. It was common in the '70s to use aluminum wiring that fatigues and causes connection issues throughout the house, if some dumb monkey decided to replace it on his own he may have made the outlets one run to save a few precious inches of copper. I hope not, though.

 

[Cherian]

Im guessing the 100 amp breaker is the main panel breaker. I would not think anyone would wire all the 15 amp outlets in the house to a single 100 amp breaker. 14 awg wire in the walls would get real hot if this was the case.

 

[tav1]

Need more info

It is not clear to me what wiring setup you have there. I can see only having a 100 amp MAIN breaker, which should feed many (10-20) smaller circuit breakers of 15-20 amps each. This would be normal, and I think houses built in the 60s and 70s might only have a 100 amp main breaker. But, if you have all of the wired circuits going to just ONE 100 amp breaker (main or otherwise), this would be bad because the wiring on any individual circuit, which is probably 12 or 14 gauge (good for about 15-20 amps respectively) would not be protected. I don't see how someone could literally place all of the wires into one breaker without having some bus bar assembly.

So, do you have many smaller breakers feeding the various circuits? One of which would be the GFCI type breaker that feeds the bathrooms.

Let us know.

Torry V.

PS This would be WRONG, but even if you had all of the house circuits going into one 100 amp breaker (WRONG), each circuit will only draw as much current as it requires. The problem occurs when you overload an individual circuit (go over the 15 amp rating of the wire). A 100 amp breaker will continue to feed a circuit "thinking" everything is normal (less than 100 amps), but in the meantime you are overheating the wiring and receptacle which is only rated for 15-20 amps. That's how a fire starts.

 

[Ron]

There is probably a sub panel at another location.

 

[Tube60]

There is probably a sub panel at another location.

I checked for that; there isn't. There's a main breaker from the utility pole, the aforementioned GFI receptacle for the bathrooms, the 240v breakers (2) and the 100a breaker for the outlets. I'm not particularly worried because the chances of high-current devices on all outlets running at the same time are nil, and that scenario would overheat the wiring. Wiring is 14 AWG copper. I'm not sure how the house was sold the way it is to my parents! I'm concerned I'll have to re-do the wiring to code when I list the house.
Thanks for the replies so far!

 

[twich54]

I'm not particularly worried because the chances of high-current devices on all outlets running at the same time are nil, and that scenario would overheat the wiring. Wiring is 14 AWG copper.

Tube, You SHOULD be worried ! From what you described , you have a potential dissaster waiting to happen. I have never heard of such a thing.

Get a qualified electrician in there ASAP and correct that mess !

 

[Tube60]

Get a qualified electrician in there ASAP and correct that mess !

Yup! Planning that. Kind of amazing there's never been a problem in the 14 years I've lived there. I can just imagine an active family moving in and overheating the wiring with H.T., computers, and other devices. Would I be liable if the house burns down?

 

[C.A.P]

Im guessing the 100 amp breaker is the main panel breaker. I would not think anyone would wire all the 15 amp outlets in the house to a single 100 amp breaker. 14 awg wire in the walls would get real hot if this was the case.

Exactly ! No way every plug would last with them hooked to 100 amps. My main breaker is only 60 amps. I have a separate sub panel for my Hot water heater and separate 220 40 amp breakers for the pump, stove (which that space is being used now with 2 dedicated 20 amp 110volt lines and separate breakers for the amp and Pre amp-CD player) .

In the late 70's it wasn't odd to have a main panel breaker at 100 amps. ! Most of the houses did not have the dedicated hard lines like we do now!

 

[Tube60]

The 100a breaker on my panel is marked "outlets". I don't recall what the main breaker is, but it's marked "main". The attic has a mad octopus of flex conduit going to junction boxes, all stemming from a common point that's hidden from insulation that I can tell. I'll have to uncover it to see what's going on there.
A good friend of mine is really good with such things (he completely rewired his shop/residence) so I'll get his advice.

 

[DrJRapp]

Would I be liable if the house burns down?

Since you are aware of the problem you must disclose it to potential buyers. If you do and they accept the condition you are not liable. If you don't disclose the condition then it is a form of fraud that COULD cause you to be held liable.

 

[MotorToad]

The 100a breaker on my panel is marked "outlets". I don't recall what the main breaker is, but it's marked "main". The attic has a mad octopus of flex conduit going to junction boxes, all stemming from a common point that's hidden from insulation that I can tell. I'll have to uncover it to see what's going on there.
A good friend of mine is really good with such things (he completely rewired his shop/residence) so I'll get his advice.

That's what I was afraid of... It sounds like there is one wire leaving the panel and outlets are spliced off that locally. The good news if there are junction boxes is that the wiring for the outlets in the walls should be accessible and you can run new wires for several areas (the same as it should have been done to begin with) to the panel and give them their own 15 amp breakers. Other than some fun attic time this shouldn't be very difficult or very costly.

 

[tav1]

I HIGHLY recommend getting an electrician or a qualified person ASAP to install a panel box with multiple small breakers feeding those outlet circuits, and take care of any other loose ends/rat's nests you might have. Panel box and breakers are relatively cheap. Again, you could have an overload on 1 circuit to which the wire overheats, but to the 100 amp feeder breaker it is not a problem and it will feed the overload continuously until a fire starts.

 

[GPBobby]

Fire trap!!!!

Tube...

If all individual outlets come to your breaker box and terminate at a single 100A breaker, you are living in a fire trap!

Reason: you must draw a combined load of 100A before the breaker disconnect occurs. Given, say, an average normal load of 5 Amps on say, 5 or 6 outlets simultaneously, you would be drawing about 30A total. That means that you would have to draw an additional 70A on a single outlet before the breaker would trip. No. 14 guage wire cannot handle 70A without overheating - like instantly - becoming an in-wall fuse.

Your wiring doesn't make sense regardless of date of construction. I lived in a house built in 1940 which had 4 screw-in fuses - 15A each. You need a new breaker panel -- soon.
Robert