Wire Undersize

[pianoman13]

I am currently doing electrical work on a house that was built around 1990. I have noticed 14 awg wire in parts of the house despite the fact that all breakers for general purpose circuits are protected at 20 amps. I asked some fellow electricians who have more experience then I do. They said that 90% of the homes in america are wired this way. Maybe there are a lot of houses wired this way but I am very certain it does not meet current code requirements. In 1990 was 14 awg romex acceptable to be protected at 20 amps? Is this something I should inform the owner of? Would it be recommended to fix this problem? If so, what would be the recommended "fix" to this problem? It would take several days to check every run of romex in the house to verify the AWG. Then only change the breakers to 15 amps in the runs that contained 14 awg. I think it would be far less time consuming to simply replace all general purpose circuits with 15 amp circuit breakers whether the circuit needs it or not. Of course then you will have breakers tripping where they didn't use to trip. There are a few circuits where I am fairly certain a 15 amp circuit breaker would not be able to hold the load that is currently on it. Finally, of course the electrical panel is in a location that would make it virtually impossible to run new circuits.

 

[iwire]

They said that 90% of the homes in america are wired this way.

I think they are very wrong.

In 1990 was 14 awg romex acceptable to be protected at 20 amps?

No, you could not protect 14 AWG branch circuits with 20 amp over current protection for many more years then 1990.

Is this something I should inform the owner of?

It's an NEC violation, I would inform them and write it on my bill / time slip.

Would it be recommended to fix this problem?

Replace the breakers with 15s.

Of course then you will have breakers tripping where they didn't use to trip.

That is possible but unlikely.

There are a few circuits where I am fairly certain a 15 amp circuit breaker would not be able to hold the load that is currently on it.

If the circuit is wired with 14 AWG and will trip a 15 amp breaker does it seem like a safe idea to leave a 20 amp breaker in place?

Finally, of course the electrical panel is in a location that would make it virtually impossible to run new circuits.

Do you earn a living by doing electrical work?

If so why should the fact that fixing a legitimate problem is going to take some time put you off?

 

[LarryFine]

In 1990 was 14 awg romex acceptable to be protected at 20 amps? Is this something I should inform the owner of? Would it be recommended to fix this problem? If so, what would be the recommended "fix" to this problem?

No; yes; yes; what you say below.

It would take several days to check every run of romex in the house to verify the AWG. Then only change the breakers to 15 amps in the runs that contained 14 awg. I think it would be far less time consuming to simply replace all general purpose circuits with 15 amp circuit breakers whether the circuit needs it or not.

It might; correct; maybe, but don't, because some circuits are required to be 20a: SA, laundry, etc.

 

[480sparky]

In 1990 was 14 awg romex acceptable to be protected at 20 amps? Is this something I should inform the owner of? Would it be recommended to fix this problem?

1981 was the first year the 60? column of 310-16 had 20amps for AWG14, along with the obelisk [?] (which has been replaced with an asterick [*] these days) directing you to the bottom of the page with the 14/15a-12/20a-10/30a limitations now found in 240.4(D).

 

[dab]

write up your report to the customer and spell out that they need to call the original contractor (hopefully an ec and not a gc) to give him a chance to fix the problem. if he doesn't get satisfaction then try the contractors licensing board for his state. he may also find that some insurance that was in effect could be tapped to fix the shoddy work.

 

[lazorko]

I would wonder about the qualifications of the electricians you asked - 14NM in residential branch circuits should almost always be protected at 15A.

 

[brantmacga]

write up your report to the customer and spell out that they need to call the original contractor (hopefully an ec and not a gc) to give him a chance to fix the problem. if he doesn't get satisfaction then try the contractors licensing board for his state. he may also find that some insurance that was in effect could be tapped to fix the shoddy work.

there's also a chance that a homeowner 'upsized' these 15a circuits to 20a breakers. i've seen it done a million times. i would imagine too much time has passed since construction to do anything legally. a gc could argue the job was done to code, ,and someone else changed it.

 

[petersonra]

I think it is appropriate to point out the installation is not code compliant, and leave it at that.

Its not like this is the kind of thing that is an imminent hazard.

 

[charlie b]

Its not like this is the kind of thing that is an imminent hazard.

Probably true. But not at all true, if the following statement is accurate:

There are a few circuits where I am fairly certain a 15 amp circuit breaker would not be able to hold the load that is currently on it.

I agree with Bob?s earlier statement. If the load would trip a 15 amp breaker, and if that same load would not trip a 20 amp breaker, then allowing that load to run continuously through a #14 wire places the home at serious risk of a fire. If the HO is lucky, then perhaps overheating the #14?s would weaken the insulation system enough to cause a trip of the 20 amp breakers before there was enough heat to start a fire. But I would not count on such luck.

 

[don_resqcapt19]

If the load would trip a 15 amp breaker, and if that same load would not trip a 20 amp breaker, then allowing that load to run continuously through a #14 wire places the home at serious risk of a fire.

Given the fact that #14 is 20 amp wire in the 60 degree column, I don't see a serious risk of fire with #14 on a 20 amp breaker. Yes it is a code violation, but I don't see a fire risk.
Don

 

[charlie b]

I understand that logic, Don. But if there were no hazard, then why does 240.4(D) exist? Somewhere along the line, someone had to believe that a #14 cannot be adequately protected by a 20 amp breaker.

 

[Pierre C Belarge]

I understand that logic, Don. But if there were no hazard, then why does 240.4(D) exist? Somewhere along the line, someone had to believe that a #14 cannot be adequately protected by a 20 amp breaker.

I have always wondered about this myself. I have heard (from a very good code history buff) that the reason for 14, 12 and 10 AWG installed with the 240.4(D) requirement was/is that they are the most commonly installed conductors and they are provided with the additional protection based solely on this premise. A little added protection for most installations.

 

[winnie]

I believe that the risk is associated with damage during short circuit conditions, not with thermal overload of the insulation during continuous operation. I expect that if 14ga NM-B is loaded at 20A, that it would not come near to overheating in a normal installation.

Of course, if the insulation is damaged, that becomes a fire hazard.

-Jon

 

[FNCnca]

is that they are the most commonly installed conductors and they are provided with the additional protection based solely on this premise. A little added protection for most installations.

This is exactly what I have been told by more than one person. Now it looks like someone is going to have to do some research.:smile:

 

[realolman]

I agree with Charlie ... I would not count on such luck....

Seems to me if it's supposed to have a 15 a. breaker, it oughta have a 15 a. breaker.

"Yeah it oughta be a 15 a breaker, but a 20 'll probably be O.K".... This 20 a. breaker has 18 continuous amps it's supposed to be 16, but it'll probably be OK

I'm not sure what's the point of speculating ( however well informed ) whether or not it'll catch fire.

 

[don_resqcapt19]

Jon,

I believe that the risk is associated with damage during short circuit conditions, ...

How would that be changed when you go from a 20 amp to a 15 amp breaker? The instantaneous trips curves for these two breakers will be almost identical.
Don

 

[don_resqcapt19]

realolman,

I'm not sure what's the point of speculating ( however well informed ) whether or not it'll catch fire.

It is not speculation...Table 310.16 tells me that a #14 copper with a 20 amp load will not reach a temperature above 60?C. I have no idea why the code requires the protection it does for these smaller conductors.
Don

 

[realolman]

O K

I withdraw "speculation".

To satisfy the code's arbitrary specification of a 15 a breaker on 14 ga. wire , I suppose it oughta have a 15 a breaker. and that's what I'm going to put on my 14 ga circuits.

 

[480sparky]

Whenever I do a service update/rewire, I put all the old general purpose circuits on 15a breakers, regardless of whether they're 12 or 14. By the time I add two 20a kitchen circuits, a laundry, bath, micro, fridge, dishwasher & disposal circuits, there isn't much left on the exisitng circuits. If the wire is 12, I still use a 15a breaker because I don't know if someone added to it years ago with 14.

 

[pianoman13]

Thanks

Thanks

I definitely appreciate all of your feedback.