Why the breaker trips
- Thread starter JoeNorm
- Start date
AC\DC
Senior Member
- Location
- Lucky to know
- Occupation
- EC
install a gfci if it trips, then you know tis a GFCI issue-An then arc or vis versa.
Good old fashion short will show up on your meter- so I hope you don't keep flipping them-- I did that once thinking it was a GFCI issue until it made a load BANG- now I check
Good old fashion short will show up on your meter- so I hope you don't keep flipping them-- I did that once thinking it was a GFCI issue until it made a load BANG- now I check
ptonsparky
Tom
- Occupation
- EC - retired
Install a breaker with diagnostics after you've used a meter to check current and voltage drop across the breaker.
Using meters should be your first tests.
Master Nater
Member
- Location
- Midwest
- Occupation
- Electrical Magician
yes, install a siemens breaker. they have indicator lights that will tell you the cause for the last trip.
ModbusMan
Senior Member
- Location
- Cleveland, OH
- Occupation
- Building Automation Engineer
Square-D will indicate the last fault's cause by a time-delayed reaction when holding down the TEST button.
Sberry
Senior Member
- Location
- Brethren, MI
- Occupation
- farmer electrician
I read thru most of the instruction sheet to one I installed in older QO panel yesterday. I was going to grab it, helper might have cleaned up. Its the first afci /gfci I have used. I didnt read farther, thats neat it has some fault memory. I had a weird fault in a piece of equipment last week it probably would have shown up earlier than when it went line to line.
ptonsparky
Tom
- Occupation
- EC - retired
You can stock on your truck every one of the latest AFCI/GFCI breakers available for onboard diagnostics. Don't forget to keep track and update frequently.
A Siemens may fit most panels for testing purposes, but you can't leave it there.
A two-minute check with an amp clamp will usually tell you if it's an overload.
Swapping the dual function breaker with a GFCI only will eliminate the ground fault problem. If it trips, it's a ground fault.
You will still need a meter or eliminate loads one at time until you find the culprit.
A Siemens may fit most panels for testing purposes, but you can't leave it there.
A two-minute check with an amp clamp will usually tell you if it's an overload.
Swapping the dual function breaker with a GFCI only will eliminate the ground fault problem. If it trips, it's a ground fault.
You will still need a meter or eliminate loads one at time until you find the culprit.
ptonsparky
Tom
- Occupation
- EC - retired
Not necessarily or I should say, maybe.
Sberry
Senior Member
- Location
- Brethren, MI
- Occupation
- farmer electrician
I found a Seimens last week in a QO, I did not leave it.
AC\DC
Senior Member
- Location
- Lucky to know
- Occupation
- EC
never seen that type of seimens before either qp or the bolt on
Sberry
Senior Member
- Location
- Brethren, MI
- Occupation
- farmer electrician
The fault I refered to was in a small bandsaw and was on a grounded circuit. A plastic connector had rotted out of sight and over time simply allowed the cord to droop at the motor that it pulled the connectors in a knot. I pulled it to the bench and plugged in switch off and for some reason tripped gfci so I let it set for a wee till I had a chance and to go over with a Son the different types of faults.
What we didn know till we repaired was ground pin in the molded cord had also failed.
Genepires
Member
- Location
- Washington state
- Occupation
- Electrician
There is a diagnostics tool called in Siemens intelli-arc that seems very helpful. I haven’t had the chance to use it yet. Can only be used on 120 v 20 amp circuits though. I wish they made a 480v 3 phase 300 amp option.
ptonsparky
Tom
- Occupation
- EC - retired
hillbilly1
Senior Member
- Location
- North Georgia mountains
- Occupation
- Owner/electrical contractor
I think they are made south of the border, I found brand new Siemens in a QO panel in a food truck that was built south of the border. Wiring was horrible. Had to redo all of it.
Sberry
Senior Member
- Location
- Brethren, MI
- Occupation
- farmer electrician
Now that I think back it seems I ran across one in an older house looked strange at the time. It wasnt a deep look but as I now recall said, ok, QO then looked closer and wasnt and it had several burned buss.
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
Classified breaker? Wouldn't surprise me if Siemens has them though you may rarely see them. Such item would be classified but still would only fit in QO load centers as nobody else has bus structure close enough it would fit in. Eaton CH sort of similar but yet both these unique enough nothing else fits them unless specifically intended to fit them.
Years ago I seen GE classified breakers that fit QO. Local lumberyard (Do It center) though they also carried genuine QO breakers as well.
Thing is they were more expensive than a genuine QO so I don't know why you would buy them other than maybe at some place that doesn't sell anything Square D.
Genepires
Member
- Location
- Washington state
- Occupation
- Electrician
If it had a max function it would see the amps right before an over current event. I was wondering if a o scope could see arcing via a distorted wave form
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
Early AFCI's you likely out of luck for built in diagnostic features. Units made after about 2012 or so started to have diagnostic features to tell which function caused the last trip, particularly if they were dual function breakers.
AC\DC
Senior Member
- Location
- Lucky to know
- Occupation
- EC
Yep