Documented under sized

[Charley L. Bottger]

Here is how I document undersized breakers and or circuits. Top right breaker is a 60 amp double pole at the meter base feeding a sub-panel in a basement IR image was taken right before the breaker tripped under load test. The breaker was varying its amp load 56 to 62 amps when it tripped I terminated the test and begin writing. I luv it when the Realtor is sitting in the house and the lights go out

[Robert Meier]

What's undersized?

[Charley L. Bottger]

Originally Posted by Robert Meier

What's undersized?

The 60 amp breaker and more than likely the wire size feeding the sub-panel in the basement That had a 4 ton A/C unit electrical cook stove, dryer and all of the light circuits and some wall outlets all on one 60 amp breaker

[Russell J. Hensel]

Originally Posted by cbottger

The 60 amp breaker and more than likely the wire size feeding the sub-panel in the basement That had a 4 ton A/C unit electrical cook stove, dryer and all of the light circuits and some wall outlets all on one 60 amp breaker

What do you mean "more than likely" the wire size? Its pretty cut and dry as to what size wire can be used where.

[Charley L. Bottger]

Originally Posted by rhensel

What do you mean "more than likely" the wire size? Its pretty cut and dry as to what size wire can be used where.

Just a ply of words I don't quote wire sizes I let the sparkys make that call. I like the words (appears to be)

[David Hays]

Originally Posted by cbottger

Here is how I document undersized breakers and or circuits. Top right breaker is a 60 amp double pole at the meter base feeding a sub-panel in a basement IR image was taken right before the breaker tripped under load test. The breaker was varying its amp load 56 to 62 amps when it tripped I terminated the test and begin writing. I luv it when the Realtor is sitting in the house and the lights go out

How did you load test this breaker?

[Robert Meier]

Originally Posted by cbottger

The 60 amp breaker and more than likely the wire size feeding the sub-panel in the basement That had a 4 ton A/C unit electrical cook stove, dryer and all of the light circuits and some wall outlets all on one 60 amp breaker

Ahh, so you're saying that based on the large load the 60 amp feeder is too small?

[Linas Dapkus]

So how did you report this? Did you report that the wire was undersized? What was your evaluation as a Level III thermographer?

[Charley L. Bottger]

Originally Posted by Robert Meier

Ahh, so you're saying that based on the large load the 60 amp feeder is too small?

Yes sir that would be what I was implying being I had a 72 degrees above ambient on the wires, the amount of amp draw, the size of the breaker and the size of the wire. Call in the sparky and let them sort it out. BTW that 60 amp breaker was feeding the sub below

[Charley L. Bottger]

Originally Posted by dhays

How did you load test this breaker?

I use all in house built in appliances all the light ceiling fans bathroom /kitchen exhausts and anything else available to create a load on the panels

[Charley L. Bottger]

Originally Posted by ldapkus1

So how did you report this? Did you report that the wire was undersized? What was your evaluation as a Level III thermographer?

Linas I had temps on both feeder conductors that was close to the same indicating no loose wires that the temp was created by excessive amp. I will just report What I observed and nothing more. I saw an excessive temp and I saw the breaker trip and that is what will be in the report let the sparky determine why.

[Robert Meier]

Originally Posted by cbottger

Yes sir that would be what I was implying being I had a 72 degrees above ambient on the wires, the amount of amp draw, the size of the breaker and the size of the wire. Call in the sparky and let them sort it out. BTW that 60 amp breaker was feeding the sub below

That panel has some problems too, like the big green screw in the neutral bus.

[Charley L. Bottger]

Originally Posted by Robert Meier

That panel has some problems too, like the big green screw in the neutral bus.

That is why the sparky is coming I had the feeling that Harry did his own wiring

[Brian A. MacNeish]

Originally Posted by cbottger

I use all in house built in appliances all the light ceiling fans bathroom /kitchen exhausts and anything else available to create a load on the panels

Comments:

(1) Was the wire rated for 90*C? That is 194*F....so the wire may be 44*F below its maximum operational temp. Being electrical, there probably is a good saftey factor in that temp.

(2) In electrical as in HVAC, the concept of diversity is used in designing codes, loads and demands. Is there even a slight chance that all the appliances, AC, bath fans, all the lights, vacuum will be on at the same time? For example, in our codes with a house with individual baseboard heaters, a circuit fed with #12 AWG can have 4,800 watts of heaters potentially drawing 20 amps at odd times but........ the code talks a lot about designing for 80% loading in many instances.

(3) In this case where you have no temperature difference on the 2 conductors probably indicating a balanced circuit/load distribution on both legs of the service, I may have done a demand/load calculation.....it may have met code requirements for sizing.

[Robert Meier]

Originally Posted by Brian A. MacNeish

Comments:

(1) Was the wire rated for 90*C? That is 194*F....so the wire may be 44*F below its maximum operational temp. Being electrical, there probably is a good saftey factor in that temp.

(2) In electrical as in HVAC, the concept of diversity is used in designing codes, loads and demands. Is there even a slight chance that all the appliances, AC, bath fans, all the lights, vacuum will be on at the same time? For example, in our codes with a house with individual baseboard heaters, a circuit fed with #12 AWG can have 4,800 watts of heaters potentially drawing 20 amps at odd times but........ the code talks a lot about designing for 80% loading in many instances.

(3) In this case where you have no temperature difference on the 2 conductors probably indicating a balanced circuit/load distribution on both legs of the service, I may have done a demand/load calculation.....it may have met code requirements for sizing.

It's possible that Charley's feeling about the feeder being too small are accurate but as Brain stated the only real way of knowing is to perform a load calculation.

I do find it surprising that in Canada you can run a 4800 watt heating load on a 20 amp, 240 volt circuit.