Breaker trippng

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newt

Senior Member
I went to a customers farm today for a power quality ticket. He has 8,2 lamp high output flor. fixtures on a 20 amp breaker,panel and lights are one year old. The 20 amp breaker trips about once a month the breaker has only 13 amps of load. All the wire is in conduit and armoured cable. Would it be possible it is just a bad breaker? I told him that would be a good place to start. It is a square d panel. Is there a special breakers for this type load?
 
I have the exact same setup in my garage, though I think that I have a little higher current draw, and have never had a trip. 3 years old.
If the wire is not loose under the terminal breaker terminal creating heat, the breaker is a good place to start.
It could also be a ballast or burnt wire in a fixture making intermitant ground contact.
 

bphgravity

Senior Member
Location
Florida
Assuming there are positively no unintentional ground or short circuits in the wiring and all other elements of the system are free of faults or defects, it certainly could be a bad breaker.
 

newt

Senior Member
Thanks I think I found it the inrush current was making it trip they were all on one switch I think Im going to put them on 2 switches.
 

mdshunk

Senior Member
Location
Right here.
micromind said:
If it's a QO panel, Square D makes a 'high magnetic' 20 amp breaker. QO120HM. It's the same price as a normal QO breaker, but I've solved inrush tripping problems with it.
Exactly what I was going to suggest. I had a similar call a couple years back for some gas station canopy lights that were time clock controlled. They would occasionally trip the breaker on start-up. Naturally, being bent the way I am, I meggerred the underground conductors out, and meggerred each hot to ground. It all checked good. The HM (high magnetic inrush) breaker solved the issue.
 

sparky_magoo

Senior Member
Location
Reno
mdshunk said:
Exactly what I was going to suggest. I had a similar call a couple years back for some gas station canopy lights that were time clock controlled. They would occasionally trip the breaker on start-up. Naturally, being bent the way I am, I meggerred the underground conductors out, and meggerred each hot to ground. It all checked good. The HM (high magnetic inrush) breaker solved the issue.

I want to hear about a call where he didn't Meggar all of the conductors. A ballast swap-out perhaps?:grin:
 

480sparky

Senior Member
Location
Iowegia
sparky_magoo said:
I want to hear about a call where he didn't Meggar all of the conductors. A ballast swap-out perhaps?:grin:

If Marc was a king back in Medieval days like King Arthur, he would not have a court food taster. He would have a court food megger. :D
 

mdshunk

Senior Member
Location
Right here.
sparky_magoo said:
I want to hear about a call where he didn't Meggar all of the conductors.
Actually, most of them I don't. It might only leave the bin on the truck where it's kept maybe once a week. I'm telling all you service guysl... if you aren't using a megger to speed up your troubleshooting on certain things, you're really missing the boat productivity wise. Even if productivity isn't your main motivator, and $$'s are, it will also permit you to more easily identify in quantifiable terms equipment and conductors that should be condemned and replaced. There are certain calls, like intermittant breaker tripping, where the megger check is the right thing to do. Spent my afternoon just today at a 6-unit apartment building that had a bad water leak, and the fire department shut the power off until an electrician checked things out (that was me). Here we are, talking about not working Saturdays in another thread, and I'm taking branch circuits out of the panel and meggerring them out. I got about 80% of the building turned back on, and I have about 6 or 8 circuits total that need investigated further one day next week. Today, I was the megger hero to 6 apartments worth of people who would have otherwise been displaced. How would an electrician without a megger have checked this stuff out? Turned the breakers back on, and waited to see if something tripped or erupted in flame? :wink:
 

quogueelectric

Senior Member
Location
new york
breaker trouble

breaker trouble

newt said:
I went to a customers farm today for a power quality ticket. He has 8,2 lamp high output flor. fixtures on a 20 amp breaker,panel and lights are one year old. The 20 amp breaker trips about once a month the breaker has only 13 amps of load. All the wire is in conduit and armoured cable. Would it be possible it is just a bad breaker? I told him that would be a good place to start. It is a square d panel. Is there a special breakers for this type load?
Sounds like a bad breaker from here.
 

sparky_magoo

Senior Member
Location
Reno
mdshunk said:
Actually, most of them I don't. It might only leave the bin on the truck where it's kept maybe once a week. I'm telling all you service guysl... if you aren't using a megger to speed up your troubleshooting on certain things, you're really missing the boat productivity wise. Even if productivity isn't your main motivator, and $$'s are, it will also permit you to more easily identify in quantifiable terms equipment and conductors that should be condemned and replaced. There are certain calls, like intermittant breaker tripping, where the megger check is the right thing to do. Spent my afternoon just today at a 6-unit apartment building that had a bad water leak, and the fire department shut the power off until an electrician checked things out (that was me). Here we are, talking about not working Saturdays in another thread, and I'm taking branch circuits out of the panel and meggerring them out. I got about 80% of the building turned back on, and I have about 6 or 8 circuits total that need investigated further one day next week. Today, I was the megger hero to 6 apartments worth of people who would have otherwise been displaced. How would an electrician without a megger have checked this stuff out? Turned the breakers back on, and waited to see if something tripped or erupted in flame? :wink:

I didn't mean to pick on you. I would love to have that $200 Extech you recommended recently.

I went on a call last week. The garage was dead. It had a sub-panel fed by an old 10/3 NM w/ a 14AWG ground. There was a fault at the light switch. The 30 amp breaker never tripped. The bond wire melted in two in the main panel.

I fixed the bond and rewired the entire garage. I told the boss I wasn't satisfied. He asked what would I recommend. I replied Meggar the feeder.

I find a legitimate use for one frequently.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
sparky_magoo said:
I fixed the bond and rewired the entire garage. I told the boss I wasn't satisfied. He asked what would I recommend. I replied Meggar the feeder.
You've made Marc feel like a proud papa. :grin:
 

jute

Senior Member
Location
SO CAL
sparky_magoo said:
I didn't mean to pick on you. I would love to have that $200 Extech you recommended recently.
Hello, Does anyone have a link or distributor so I can take a look at this and what the circumstances are that this is best used for... I think I'd like to get one but unfamiliar with what's out there and the best for the buck ...Thanks, JB
 
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sparky_magoo

Senior Member
Location
Reno
jute said:
Hello, Does anyone have a link or distributor so I can take a look at this and what the circumstances are that this is best used for... I think I'd like to get one but unfamiliar with what's out there and the best for the buck ...Thanks, JB

The reccomendation was in one of the threads I read this weekend. I can't remember where.
 
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