High Amp Reading in house

[mivey]

Consider any recent work done (siding, paneling, plumbing, landscaping, etc.) as someone may have driven a nail into the wire or cut into it.

 

[ptonsparky]

Consider any recent work done (siding, paneling, plumbing, landscaping, etc.) as someone may have driven a nail into the wire or cut into it.

New or existing home may change what you look for.

Eventually that breaker may just quit tripping, sometimes preceeded by call to FD. Put a new one in after you are done and quit turning the dang thing on until after you correct the problem.

 

[bobbymari]

Which puts more resistance in the circuit and lowers amount of current flow.

correct , just giving another example as to why a breaker may not trip instantly on a short as in post 4 question

 

[timz]

high amperage on breaker

high amperage on breaker

Did you check for a back feed on that breaker

 

[ptonsparky]

Did you check for a back feed on that breaker

Could, would you, exlain what you are asking a bit? At times, most my wife would say, I am slow.

 

[hillbilly1]

Did you check for a back feed on that breaker

Could, would you, exlain what you are asking a bit? At times, most my wife would say, I am slow.

I think what he is asking, did the OP check for voltage from another breaker tied to it on an opposite leg. But I think he would have gotten bit while changing the breaker if that was the case.

 

[ptonsparky]

I think what he is asking, did the OP check for voltage from another breaker tied to it on an opposite leg. But I think he would have gotten bit while changing the breaker if that was the case.

Ahh, yes. Not sure the OP would have had time to get much of a current reading, and in that case 85 would be pretty low.

 

[timz]

high amperage

high amperage

I did not catch the post where he replaced the breaker, sorry but what I meant was what hillbilly described in his post ,a opposite phase could have been backfeeding this breaker.

 

[hillbilly1]

I did not catch the post where he replaced the breaker, sorry but what I meant was what hillbilly described in his post ,a opposite phase could have been backfeeding this breaker.

He could have been actually following 70E and turned the main off, but we know how many people actually do that with plug in breakers!:lol:

 

[ActionDave]

Yes, many of us have run into this before.

It is a called a short circuit or ground fault.

That is what you typed, but what you really want to say is, "Come over here and let me give you a hug, it will be OK."

 

[iwire]

That is what you typed, but what you really want to say is, "Come over here and let me give you a hug, it will be OK."

Yes, exactly that.

 

[sunny4444]

I would like to say thanks, I was able to correct the problem yesterday because of all the useful information in this post. Basically, I started at a receptacle in about the middle of the circuit with my ohm meter and worked my way back to a faulty receptace. I took the feed off and the circuit would function fine, at that point I just replaced the receptacle and everything on the branch worked fine. I checked voltages at devices and at CB and it all read fine. thanks again for everyone's help.

 

[templdl]

Did I miss what the heating watts was for an 85a load on 120v? If the is an issue I would be very concerned with what is happening at the point of failure. The wattage should be very humbling to be very concerned about such as letting the smoke out resulting in a fire at some unknown location. Doing so would assure that you would be able to find the source in a very short time.

 

[kwired]

Did I miss what the heating watts was for an 85a load on 120v? If the is an issue I would be very concerned with what is happening at the point of failure. The wattage should be very humbling to be very concerned about such as letting the smoke out resulting in a fire at some unknown location. Doing so would assure that you would be able to find the source in a very short time.

I don't think you missed anything, but 85A @ 120V should give you around 10.2kW. Most of it being given up at the point of failure.

 

[GoldDigger]

I don't think you missed anything, but 85A @ 120V should give you around 10.2kW. Most of it being given up at the point of failure.

In this particular case, I think that all that prevented a more visible problem (e.g. fire!) was that the resistance in the circuit was distributed over the entire length of all of the branch circuit wiring up to the fault and so the heat was not concentrated in any one place.
But 83 amps does indicate that the voltage drop in the wiring at normal current levels is probably far higher than allowed.

 

[kwired]

In this particular case, I think that all that prevented a more visible problem (e.g. fire!) was that the resistance in the circuit was distributed over the entire length of all of the branch circuit wiring up to the fault and so the heat was not concentrated in any one place.
But 83 amps does indicate that the voltage drop in the wiring at normal current levels is probably far higher than allowed.

What is allowed? 3 - 5% in the informational note in the NEC is just a suggestion not a requirement.

If specific equipment has a requirement then it applies to that equipment.

Small dry transformers possibly may not be able to deliver 83 amps

 

[GoldDigger]

What is allowed? 3 - 5% in the informational note in the NEC is just a suggestion not a requirement.

Thanks for the reality check!
If the limiting factor is in the wiring resistance, it would imply a voltage drop in the neighborhood of 25 volts for a full amperage load. But if it is a transformer which is limiting it, what does that say about the service itself? What is expected of the feed to the panel?
The OP stated that it is a house with a 200A service.

 

[kwired]

Thanks for the reality check!
If the limiting factor is in the wiring resistance, it would imply a voltage drop in the neighborhood of 25 volts for a full amperage load. But if it is a transformer which is limiting it, what does that say about the service itself? What is expected of the feed to the panel?
The OP stated that it is a house with a 200A service.

I have seen 200 amp service (though 100 amp would have been sufficient) with 400+ feet of 4 AWG aluminum overhead conductor supplying them. Did not do the VD calculations, but was not able to get the POCO to move the transformer closer or increase conductor size, yet customer wanted to know why the lights dim so bad whenever AC, or any just about any motor starts.

 

[hillbilly1]

Yeah, it's hard to get the poco to upgrade their wiring, I did an addition to a country store where at noon during the summer, the voltage would drop down to 100 volts. They had an existing 400 amp service with 380 amps on it. The poco had a 4/0 AL lateral run to it from a pole mounted transformer close to 300' away. I moved the service closer to the transformer, and increased it to 1200 amps. The poco wanted to run two 4/0 AL service drops to it. Had a meeting with the engineers and got them to parallel two 350 kcmil s to it. No more voltage problems for a while, at least until they blew the undersized transformer at the pole.:roll: