GE 20 amp Breaker tripping intermittently

Status
Not open for further replies.
H

hanklazard

Member
Location
Alabama
Occupation
Electrician
There's maybe 8 medium base can lights, 3 outlets, and 2 switches functioning as a 3 way for the lights.
The entire load on this branch circuit is barely 3 amps, but regularly it will trip sometimes after 20 minutes or sometimes it will take 8 hours to trip breaker. It's a standard 20 amp GE. It'll also trip when the lights are off and there doesn't appear to be any major appliances connected. Are the travelers damaged? I was considering putting low amperage fuses in the junction box just to narrow it down temporarily. Any other ideas?
 
How long have you measured current on the circuit?

If you have a meter with a min/max recording you might be able to see if it’s a slow happening overload or possibly a plugged in device causing a high current SC/GF.

If you believe there is nothing on the circuit capable of a overload. Take ohm readings from ungrounded conductor (hot) to your EGC And see if there is contact between the two somewhere when switches and devices are used and in different positions.

If I found nothing there I would swap with another ckt breaker and see if I got the same results.
 
Last edited:
Dsg319 said:
How long have you measured current on the circuit?

If you have a meter with a min/max recording you might be able to see if it’s a slow happening overload or possibly a plugged in device causing a high current SC/GF.

If you believe there is nothing on the circuit capable of a overload. Take ohm readings from ungrounded conductor (hot) to your EGC And see if there is contact between the two somewhere when switches and devices are used and in different positions.

If I found nothing there I would swap with another ckt breaker and see if I got the same results.
Click to expand...
Ohm reading between hot and equpiment ground is a good idea thanks. I've measured the current for a few minutes only about three amps haven't done it for several hours.
 
I hadn't seen it happen until I moved to Houston, but I've seen breakers trip on thermal because heat couldn't dissipate. No overload.
I second checking the bus and breaker stab.

Sent from my SM-G965U using Tapatalk
 
I agree with swapping or changing the breaker and checking the stabs first.

hanklazard said:
There's maybe 8 medium base can lights, 3 outlets, and 2 switches functioning as a 3 way for the lights.
The entire load on this branch circuit is barely 3 amps, but regularly it will trip sometimes after 20 minutes or sometimes it will take 8 hours to trip breaker. It's a standard 20 amp GE. It'll also trip when the lights are off and there doesn't appear to be any major appliances connected. Are the travelers damaged?
Click to expand...

One of the 3-way switches will be connected to the line (hot) and the other one will be connected to the load. If one of the travelers is causing the problem then it shouldn't matter which position that you set the 3-way for the load. But it will matter for the 3-way that's connected to the hot side, because it selects which traveler will be powered up.
Have you verified that the breaker will still trip when the two 3-ways are in all 4 of their possible positions? If you know which 3-way is connected to hot, then you only have to test that 3-way in both of its positions, and the other 3-way shouldn't matter. If the breaker trips no matter how you set the switches, then the travelers are not the problem.

Can you disconnect all or at least some of the outlets and still have the lights connected? This might help in isolating the problem to a specific area.
 
Breakers "trip" for one of two reasons: they're overloaded or faulty. If you're fairly confident it's going to trip sometime in an eight hour period, put an ammeter that can capture high peak on it. Switching it to another same size breaker and checking if and when it trips may point you in the right direction. Hopefully this will do it. Checking connections on an unmapped circuit won't be fun.
 
Customers lie (knowingly or unknowingly). Sometimes its like pulling teeth to get adequate information for troubleshooting.
"Was anything else plugged in?"
"No nothing." "Was just watching the TV and there was a flash and lights went out." I called out my husband and he found the heater breaker breaker was tripped." (Baseboard electric heat)
"Where was the flash?"
"A large bright flash in the middle of the heater"
Investigated the heater for evidence of "Flash" saw a couple of small burns but not how it would make sense, in the middle of the heater not at the power ends. "Did your husband turn the breaker back on?"
"No, and I still don't have lights" "I'm afraid of electrical fires so I wouldn't let him"
Went to basement to check the breakers. No double pole tripped. Asked again, "Did he turn the breaker back on?"
"No"
"Did you have any breakers turned off for some reason?" A single pole was tripped.
"Don't know"
Went back up and metered, was live, went back down an shut off breaker, tested and no shorts. So I ask "Did you unplug anything?"
"No"
While testing noticed a dust ring and marks from where a chair and lamp had been moved some. "Did you move the chair and lamp?"
"Yes so you could get to the heater."
So happened to looked for a receptacle and there was none, and also noticed an extension cord coiled on floor at opposite end of heater. "Were did you have the lamp plugged in?"
"I didn't have it on last night."
"Is it normally plugged in?"
"Yes"
"Where? There is no receptacle here."
"I use the extension cord over there."
Examined the cords of both and find a couple of melt through points at an exact point of the flash marks on the heater. After additional pointed questions she admitted that the extension cord was on top of baseboard. Obviously the lamp cord had fallen into heater and shorted out. And the tripped single pole was that circuit.
 
synchro said:
One of the 3-way switches will be connected to the line (hot) and the other one will be connected to the load. If one of the travelers is causing the problem then it shouldn't matter which position that you set the 3-way for the load. But it will matter for the 3-way that's connected to the hot side, because it selects which traveler will be powered up.
Click to expand...
I'd put a multimeter on the homerun and start flipping switches and see if it make any difference. If not, as mentioned, put a logger on it and see if you can capture the current when it trips. Chances are, the breaker is schidt. If wiring is faulty, normally, it would trip right away when you changed travelers.....if it's a dead short of course. Good luck.
 
If you suspect poor breaker to bus connection or breaker to branch conductor connection - IR thermometer should pick up the excessive heating. To speed up troubleshooting process for this temporarily connect a high load like a hair dryer or heat gun, if connections are that bad they should significantly heat up in less than a minute with that kind of load on them.

Temporarily add this load to end points on the circuit to get same effect on any connections between that point and the circuit origin. If actual load is causing something to heat up then fault out, you should be able to make it do so more quickly with the higher load on it. If it is a lamp socket that faults after heating up, it likely is obvious if you just take a close look at the socket, but megger test might indicate something is wrong even when cold.
 
Shaneyj said:
I hadn't seen it happen until I moved to Houston, but I've seen breakers trip on thermal because heat couldn't dissipate. No overload.
I second checking the bus and breaker stab.

Sent from my SM-G965U using Tapatalk
Click to expand...

Shaneyj said:
I hadn't seen it happen until I moved to Houston, but I've seen breakers trip on thermal because heat couldn't dissipate. No overload.
I second checking the bus and breaker stab.

Sent from my SM-G965U using Tapatalk
Click to expand...
Ambient temperature definitely can have an effect on circuit breakers and cause nuisance tripping. I've solved tripping issues on occasion by simply moving the breaker to a different place in the panel. If a breaker in question is between two heavily loaded circuit breakers, the additional heat combined with the heat from the circuit being affected can impact the bimetallic strip and cause tripping.
 
Rick 0920 said:
Ambient temperature definitely can have an effect on circuit breakers and cause nuisance tripping. I've solved tripping issues on occasion by simply moving the breaker to a different place in the panel. If a breaker in question is between two heavily loaded circuit breakers, the additional heat combined with the heat from the circuit being affected can impact the bimetallic strip and cause tripping.
Click to expand...
This is a great idea. I've used the cheaper laser thermometers to find hot spots in the panel and lose connections, but I could definitely see a smaller amperage breaker tripping if it was next to a heat pump breaker.
 
ptonsparky said:
Heat from nearby breakers has to be extreme. Usually they will be severely overloaded or have poor connections themselves. You will not need anything but your hand to find them. Or your nose.
Click to expand...
In one instance, it was (3) 277v lighting circuits. All continuous loads. 15,16,14 amps top to bottom. The breaker with the 16 amp load was moved to another spot in the panel and I installed a panel blank. Problem was solved.
 
Status
Not open for further replies.
Top