Breaker Tripping...why?

[Radical540]

Hi Guys..
So I come back from my Nashville business trip and my wife says that our sunroom breaker has tripped a few times.

This particular circuit I'm familiar with. It's a 20amp circuit that feeds (1) double duplex outlet in the sunroom (of which only a TV & cable box are on) and then proceeds to go under a concrete slab and then ultimately feed my garage. (yes! don't shreak. My garage is fed by one 20 amp circuit. Last summer's project was to run another 80amps to the garage; but digging a trench, etc kept getting moved farther and farther down the "summer project list", now its Fall in the midwest)

So now, (before we get any amount of snow) I need to figure out why this breaker continues to trip (the last time I reset it this morning, it was OK for about 3 hours & then tripped again; for no apparent reason) when the circuit is not under any heavy load (??)
Do breakers go bad?
Need some direction where/how to start diagnosing..

Thanks!

 

[pattenp]

What kind of wire is used under the slab and is it in conduit. My first thought is you have a wire that's gone bad and is shorting out due to moisture. Is garage attached to the house?

Edit: I guess the garage is detached since you're talking about digging a trench. And breakers do go bad but I don't think that's the problem.




*

 

[myredracer]

Get a clamp-on ammeter (cheap at HF) and see how much is actually flowing (take panel cover off).

I would not suspect a bad breaker, but it is not impossible. You could try swapping the hot wire onto another breaker and see what happens.

20 amps is a lot of current to go missing somewhere. Potentially dangerous too.

 

[Radical540]

What kind of wire is used under the slab and is it in conduit. My first thought is you have a wire that's gone bad and is shorting out due to moisture. Is garage attached to the house?

Edit: I guess the garage is detached since you're talking about digging a trench. And breakers do go bad but I don't think that's the problem.




*

Based on what I've previous seen, I'm assuming it's the gray "direct-burial" wire. That seems to be what builders used in this subdivision in the 80's.
(How to find a wire break?)
*UPdate...it just tripped again..this time only about an hour. My first course of action I think is going to be to open up the boxes, and junction boxes I've worked within before. See if I seen anything loose/strange going on.

 

[Radical540]

Get a clamp-on ammeter (cheap at HF) and see how much is actually flowing (take panel cover off).

I would not suspect a bad breaker, but it is not impossible. You could try swapping the hot wire onto another breaker and see what happens.

20 amps is a lot of current to go missing somewhere. Potentially dangerous too.

Ok.I think I Might have one. What am I supposed to be seeing?

*UPdate...it just tripped again..this time only about an hour. My first course of action I think is going to be to open up the boxes, and junction boxes I've worked within before. See if I seen anything loose/strange going on.

 

[LB-1911]

Open up the box in the sunroom and disconnect the garage and see if it trips again.

Other than a garage door opener what else is plugged in?

 

[Syberia]

Likely the wire is damaged underground, especially if it was direct buried and not in conduit. Shorting either to the neutral/ground wire in the cable, or to the earth itself.

This is why I don't like direct buried cable, even if it is code approved.

 

[pattenp]

If you haven't already done so, the best you can do is disconnect everything being powered on the circuit and see if it still trips overtime. You can try a continuity test across the wires but a moisture short will most likely not show up because of the low voltage that the meter uses. The clamp on amp meter test may show some low amperage drain but the reducing time delay between trip tells me the wire has some damaged insulation that is getting worst as it shorts.

You definitely need to disconnect your TV from this circuit until you figure it out. The short can back feed power over the ground or neutral and damage the TV.

*

 

[rlitman]

Ok.I think I Might have one. What am I supposed to be seeing?

*UPdate...it just tripped again..this time only about an hour. My first course of action I think is going to be to open up the boxes, and junction boxes I've worked within before. See if I seen anything loose/strange going on.

No, start with the clamp meter before you start making things more complicated.

Clamp the meter around the wire as it exits the breaker and see what the current is. On a 20A breaker, you should not have more than 16A of continuous load, so that's a number to start with. Depending on the breaker, the temperature, and the alignment of the planets (and other factors, some of them random), I guess it would take around 22-24A to trip in an hour on the thermal portion of the breaker.

If you're seeing more current than you expect, turn off and unplug everything, and see if it drops to 0 or not.

 

[nh_yota]

It is not uncommon for UF cable (or any cable run underground) to go bad and have a high resistance short that may not trip the breaker but still leak current to the neutral or ground. After a while the short may draw enough current to finally trip the breaker.

 

[Radical540]

Thanks so far guys...these are great ideas, but perhaps more than I choose to do myself. (I know when it's time to simply as "....and who do I make that check out to?)
However, I've pulled the panel- no funny business in there
I've pulled the outlet covers for the (2) sunroom outlets, no funny business there
I've pulled the junction box cover at the bottom of the pole of a "gas lamp" (electrical in this case). There are (3) lines that feed into this junction box:
1- from the panel (via underground)
1- that runs to the junction box that feeds the sunroom
1- that continues on and feeds the garage
they are all wire capped appropriately - However, the (aluminum) box is filled with crusty corrosion, etc.
I'm hoping this is the low hanging fruit.. I'm going to clean it up and refit and tape the caps....
Stay tuned.....

 

[pattenp]

Is the breaker that's tripping a GFI breaker? Based on your description of where this circuit runs sounds like it should be on a GFI breaker.

 

[Shiftless]

Maybe easier than all of that would be to turn off everything in your house and watch your electric meter for a while.

 

[Radical540]

Some of the wires in the wirenuts in the "gas lamp" junction box were either loose or not in the nuts but barely. I'm going to re-do it, new wirenuts, secure everything well, re-tape the nuts, etc. and see what happens.
The condition of this junction box was nasty!!

 

[myredracer]

As mentioned, find the hot wire at the breaker and put the clamp-on meter on that wire. If it is indeed showing some current with everything supposedly turned off downstream, you *could* disconnect the wire in the sunroom that feeds downstream from there to the garage and see what the ammeter shows at the panel.

Panels usually don't have a GFCI breaker because they are so expensive compared to a GFCI recept. But if it does happen to be one, then you probably have a ground fault somewhere.

Since the panel cover is off, as I mentioned above, a simple test is to try swapping the circuit onto another breaker temporarily and see if that trips.

Also as mentioned above, the breaker will not trip at 16 amps, but more like around 22-24 amps after a long period of time. Breakers have an inverse time-current characteristic - the higher the current, the sooner it trips.

If you had a bad splice somewhere causing this, the box and wires would likely be melted and burned to a crisp. 20 amps = 2400 watts!

It is very likely the run to the garage that is no good. If so, it should be disconnected pdq and not used for safety reasons.

 

[LB-1911]

Some of the wires in the wirenuts in the "gas lamp" junction box were either loose or not in the nuts but barely. I'm going to re-do it, new wirenuts, secure everything well, re-tape the nuts, etc. and see what happens.
The condition of this junction box was nasty!!

I've pulled the junction box cover at the bottom of the pole of a "gas lamp" (electrical in this case). There are (3) lines that feed into this junction box:
1- from the panel (via underground)
1- that runs to the junction box that feeds the sunroom
1- that continues on and feeds the garage

Is the "sunroom" a converted porch?

 

[Radical540]

Hi...........
I re-worked the "gas-lamp" wires in the junction box. As I said they were nasty, and quite loose in the wire nuts. One (black) wire was barely in the wire nut - I had to solder on some extra length to get it to fit comfortably. The bare copper wires were loose in the wire nut too.

When I wrapped it all up, even though it was supposedly a "wet environment" junction box cover,(with gasket) I sealed it with silicone sealer to be double sure it was sealed from "the elements". I'm keeping my fingers crossed I found the problem.
I wanted to fix this first, as it was the easiest place to start; and if you all saw the condition of the box, most of you would agree.

Clearly, I need to make the new garage circuit a higher priority come Spring '16!!

 

[sands35]

Hi...........
I re-worked the "gas-lamp" wires in the junction box. As I said they were nasty, and quite loose in the wire nuts. One (black) wire was barely in the wire nut - I had to solder on some extra length to get it to fit comfortably. The bare copper wires were loose in the wire nut too.

When I wrapped it all up, even though it was supposedly a "wet environment" junction box cover,(with gasket) I sealed it with silicone sealer to be double sure it was sealed from "the elements". I'm keeping my fingers crossed I found the problem.
I wanted to fix this first, as it was the easiest place to start; and if you all saw the condition of the box, most of you would agree.

Clearly, I need to make the new garage circuit a higher priority come Spring '16!!

I'll be the person doing the work didn't size the wire nuts properly if they are loose.

There is some debate on the practice of soldering wires. Make sure they are twisted then tape well.

The "proper" way to fix a short wire is to pull new wire.

The wires are behind drywall or paneling? Or is it surface mount?

Alternative:

A shortcut would be to install a handy box or plastic old work box ~12" away from the offending junction box to add in some new wire of the correct free length out of the offending junction box. The handy box intercepts the old wire and that gives you ~12" of old wire sticking out of the handy box to connect a new wire with nuts. The new wire then goes into the original junction box.

Yeah, better off running new wire to the garage rather than under the slab from a porch light circuit.

 

[Syberia]

What? No one is going to pull another wire if one gets cut a little short, but still in the box. Especially if it's behind drywall, stapled to studs, etc. This is the easiest way to extend a wire:

http://www.homedepot.com/p/Ideal-Sp...sh-In-****-Splices-10-Pack-30-1342S/202894306

 

[Radical540]

What? No one is going to pull another wire if one gets cut a little short, but still in the box. Especially if it's behind drywall, stapled to studs, etc. This is the easiest way to extend a wire:

http://www.homedepot.com/p/Ideal-Sp...sh-In-****-Splices-10-Pack-30-1342S/202894306

Hell ya! I agree. Talk about making a mountain out of a mole hill. I've had to "extend" wire a few times in my life and never had an issue soldering on an extra length of wire. However, I never knew these connectors existed. Thanks for sharing..

Oh, and so far so good! The circuit has been "live" now since my last writing. Hopefully I found the problem; I'm reasonably sure I did. Makes me wanna start digging my trench now.
BTW; what gauge wire (copper or aluminum ?) to make a 50' pull to the garage....in plastic (2") conduit, say 80 amps ??? ALSO, can I put a length of COAX cable in the same 2" conduit with the electrical line; for a TV? (wasn't sure if there is some RFI thing to be concerned with)

 

[pattenp]

#2 aluminum is good to 90A. Use either MHF or THHN/THWN or RHH/RHW/USE wire. And no on the coax in the same pipe with line voltage wire. Run a separate pipe for the coax.

 

[rlitman]

You need a separate pipe for the coax, but they can be parallel and close together. I'd suggest pulling in a Cat5e wire along with the coax.

 

[Radical540]

Damn it! I thought that was going to be the case! Damn it.
The real ****** thing is that my damn Cable company AND the electric company could theoretically give me a drop from the pole that is only 8' from my garage - but of COURSE they won't.. Stupid on their part, because it would be a separate bill with separate "fee's" that I'd be OK with paying - but again they won't because the out building isn't more than 500' from the dwelling. LAME!!

 

[Radical540]

You need a separate pipe for the coax, but they can be parallel and close together. I'd suggest pulling in a Cat5e wire along with the coax.

Yes, agreed. Is there any loss of wi-fi signal at a certain length of pull?

 

[Syberia]

If I'm recalling correctly, ethernet cable is good to 400' without signal degredation.

 

[rlitman]

Is there any loss of wi-fi signal at a certain length of pull?

If you mean ethernet (and not wi-fi, because wi-fi is wireless)...

If I'm recalling correctly, ethernet cable is good to 400' without signal degredation.

Technically 328' is a hard limit based on signal timing (nothing to do with interference or degradation, which can cause issues at shorter lengths).

 

[pattenp]

Specs on 5e is 100 meters or 328ft max.

 

[Radical540]

Yep, meant ethernet..my bad.
All good then....I'm well within 328'

 

[wyliesdiesels]

....My garage is fed by one 20 amp circuit. [/B]Last summer's project was to run another 80amps to the garage; but digging a trench, etc kept getting moved farther and farther down the "summer project list", now its Fall in the midwest)...
Thanks!

Code permits only 1 feed to a detached structure. If and when u do run a new feeder to the garage the existing 20a circuit will need to be abandoned.

 

[rlitman]

Code permits only 1 feed to a detached structure. If and when u do run a new feeder to the garage the existing 20a circuit will need to be abandoned.

Well, the wire cannot be used as a feed any more, though it could potentially be re-purposed. For example, it could be used with a switch in the house to control lights in the garage (or something else weird like that).

But yes, whatever this wire feeds now will need to be disconnected from this wire, and hooked into the new panel in the garage (unless you want to abandon it all).

 

[Zeke]

Start digging....

 

[Radical540]

Who sits around and makes up these asinine "codes"? I mean really..some of them make sense, but others....? I can see a bunch of bureaucrats (Definition: an official who works by fixed routine without exercising intelligent judgment. ) sitting around a table thinking of ways to make simple tasks overly difficult. I do like rlitman's suggestion though....also if pattenp is right, I'll pull 2 gauge aluminum for 90 amps, and at that point the 20amp feed will be moot point.

 

[Radical540]

Start digging....

BTW, how deep? Logic would tell me that it doesn't have to be below a "frost-line" because it's not a foundation; that may have to contend with "heaving" - but.......I'm imagining there is another asinine code dealing with this too (?)

 

[Radical540]

Code permits only 1 feed to a detached structure. If and when u do run a new feeder to the garage the existing 20a circuit will need to be abandoned.

....in Michigan, UNLESS the structure is 500' from the dwelling...
(..or you're willing to provide the work-order employee a $500 XMas present ....as he was hinting at)

 

[Syberia]

Well let's see, there's the arc fault manufacturers bribing the CMP to peddle their product...

But the ones discussed so far in this thread actually make sense. Only one circuit to an outbuilding because that way you only have one place to shut the power down, without some things remaining on. Don't mix low voltage and line voltage because of interference.

BTW, how deep? Logic would tell me that it doesn't have to be below a "frost-line" because it's not a foundation; that may have to contend with "heaving" - but.......I'm imagining there is another asinine code dealing with this too (?)

My understanding is that heaving will still damage a buried conduit or cable.

 

[pattenp]

Who sits around and makes up these asinine "codes"? I mean really..some of them make sense, but others....? I can see a bunch of bureaucrats (Definition: an official who works by fixed routine without exercising intelligent judgment. ) sitting around a table thinking of ways to make simple tasks overly difficult. I do like rlitman's suggestion though....also if pattenp is right, I'll pull 2 gauge aluminum for 90 amps, and at that point the 20amp feed will be moot point.

What do you mean if I'm right. That hurt.

 

[pattenp]

BTW, how deep? Logic would tell me that it doesn't have to be below a "frost-line" because it's not a foundation; that may have to contend with "heaving" - but.......I'm imagining there is another asinine code dealing with this too (?)

18" of cover if in conduit and 24" of cover if direct bury, if I'm right.

 

[wyliesdiesels]

....in Michigan, UNLESS the structure is 500' from the dwelling...
(..or you're willing to provide the work-order employee a $500 XMas present ....as he was hinting at)

Huh?

There is no distance exception to this code.

And its for safety!

 

[rockwithjason]

Who sits around and makes up these asinine "codes"? I mean really..some of them make sense, but others....? I can see a bunch of bureaucrats (Definition: an official who works by fixed routine without exercising intelligent judgment. ) sitting around a table thinking of ways to make simple tasks overly difficult. I do like rlitman's suggestion though....also if pattenp is right, I'll pull 2 gauge aluminum for 90 amps, and at that point the 20amp feed will be moot point.

What asinine code are you refering to?

 

[checkthisout]

Who sits around and makes up these asinine "codes"? I mean really..some of them make sense, but others....? I can see a bunch of bureaucrats (Definition: an official who works by fixed routine without exercising intelligent judgment. ) sitting around a table thinking of ways to make simple tasks overly difficult. I do like rlitman's suggestion though....also if pattenp is right, I'll pull 2 gauge aluminum for 90 amps, and at that point the 20amp feed will be moot point.

IMO, Mechanical codes are actually the most sane and common sense you will find. They amount to good practice and generally generate a consistent install no matter what shape or size a structure is.

The irony here, I mean I'm not saying that wiring installed to code can't fail but do you suppose the wiring that's giving you hell right now is "up to code" and was done with permits and inspected?