tripping breaker Advice

[mobiledynamics]

riddle me this.....if it’s not a wire overheating/drawing too much and or if the breaker has been replaced, what would cause a breaker to just trip on it’s own ?

1st time , jusrt swapped breaker

just happened again and the same 2 breakers. One of them is 220 and another is 110. And either it’s just shear luck or conincidence, but again they have tripped.

 

[LXCam]

Do you have access to a amp meter. You need to get a measurement first or prove there's no load before anything more than a guess could be provided.

 

[SlappyWhite]

I would double check amperage with a metre before anything else.

After that, it could also be heat, if the breaker gets too hot it trips. The heat could be from bad connections either at the panel bus or at the screw terminal. You have replaced the breaker(s), hopefully ruling out the wire connection, so I would have a gander at the bus to make sure there are no issues. How old is the panel and what condition is it in? Aluminum or copper wire? Did the breaker feel warm at all right after tripping? Do you walk to work or carry a lunch?

While this is not all that common in my limited experience on breakers. I see this problem all the time on older fuse panels.

 

[sberry]

Or something is shorting it. I have ran across a handful of truly bad breakers in a career.

 

[Greeny]

What is on those circuits?
What is plugged in?
My first suspicion, assuming the home is not brand new, is that something on the outlet is causing the CB's to trip.

 

[teamextreme]

The fact that 2 breakers are tripping at the same time is a clue and a very odd situation. I don't think I've ever seen an issue like that. I would tend to suspect there is an intermittent dead short between phases of each breaker, somewhere downstream in the building, causing both breakers to trip. Only other explanation I can come up with is bad breaker stabs on one breaker causing overheating and tripping of that breaker as well as an adjacent one due to heat proximity. Where are the breakers located relative to one another? Which of the 2 breakers did you change the first time? Did you inspect the bus closely?

 

[wyliesdiesels]

Definitely odd.

What do these breakers feed?

 

[LXCam]

Will either one trip is the other is left off? If you haven't tried that do it. Also how often does this happen. Is it something that's consistent of totally random.

 

[rnscustom]

Adding my 3 cents just to follow it, do the two breakers feed things in the same area that Gould be getting wet / pinched by something etc.

 

[mobiledynamics]

The breakers all feed onto the same panel. Actually on the 1st incident, there was a couple other breakers that tripped as well.

In the most recent scenario, 2 breakers tripped, both of which tripped the 1st time as well.
Breaker A : 220 : Phase A B
Breaker B : 120 Phase C

Amp probe shows less than 1/6 of the amp draw on the wire/circuit rating.
Continuity checks out
Connections on plugs/breakers/outlets look good.

No rhyme or reason why it's tripped.

Breaker A: when it occured 6 months ago, a new breaker replace it. The *former breaker*, itself, was less than 9 months in use as well. Technically, the original breaker was a fairly new breaker in itself.

 

[wyliesdiesels]

The breakers all feed onto the same panel. Actually on the 1st incident, there was a couple other breakers that tripped as well.

In the most recent scenario, 2 breakers tripped, both of which tripped the 1st time as well.
Breaker A : 220 : Phase A B
Breaker B : 120 Phase C

Amp probe shows less than 1/6 of the amp draw on the wire/circuit rating.
Continuity checks out
Connections on plugs/breakers/outlets look good.

No rhyme or reason why it's tripped.

Breaker A: when it occured 6 months ago, a new breaker replace it. The *former breaker*, itself, was less than 9 months in use as well. Technically, the original breaker was a fairly new breaker in itself.

What do you mean the breakers all feed onto the same panel? You mean you have more than one double pole breaker feeding a panel?

You mentioned C phase. Is this a 3 phase system?

 

[maintguy]

120 volts. In an a,b,c ( 3 phase system) please explain

Also a member. Will tale you If. There is a problem on the circuit

Why are these breakers being replaced and not reset?

 

[mobiledynamics]

It's 3 phase.
It's actually in my office space - newly built last year. Old panel but new breakers/wire runs...

The breakers are not adjacent to each other.
The 1st time it tripped, it was about 9 months after moving into the space.
NO change in extra load added on the tripped breakers...
The breaker on the 220 sitting on phase 1/2 was changed. The others the tripped were just flipped back on.

Strangely enough, the breakers tripped again....last week.
The 1st time I thought it was strange. Suspected maybe the were doing some work on a adjacent office and some idiot might have done a short that did weird things to the panel...


But it happened again, so it's not a weird fluke. The ? is what.
Local spark says he doesn't see anything wrong...check out the panels, the outlets connections, etc.

He sorta inferred that if it trips again, he will do a deep dive diag and most likely ~may~ replace the wire runs....

 

[wyliesdiesels]

120 volts. In an a,b,c ( 3 phase system) please explain

Also a member. Will tale you If. There is a problem on the circuit

Why are these breakers being replaced and not reset?

There is 208Y/120v service where there is 120v potential line to neutral on all 3 phases and 208v line to line.

It's 3 phase.
It's actually in my office space - newly built last year. Old panel but new breakers/wire runs...

The breakers are not adjacent to each other.
The 1st time it tripped, it was about 9 months after moving into the space.
NO change in extra load added on the tripped breakers...
The breaker on the 220 sitting on phase 1/2 was changed. The others the tripped were just flipped back on.

Strangely enough, the breakers tripped again....last week.
The 1st time I thought it was strange. Suspected maybe the were doing some work on a adjacent office and some idiot might have done a short that did weird things to the panel...

But it happened again, so it's not a weird fluke. The ? is what.
Local spark says he doesn't see anything wrong...check out the panels, the outlets connections, etc.

He sorta inferred that if it trips again, he will do a deep dive diag and most likely ~may~ replace the wire runs....

So you have 240/120 Delta?

There is no such thing as 220v 3 phase in the US.

If you do have 240v line to line, then watch out for the stinger leg as it is 208v line to neutral.

What brand of breakers?

Are these AFCI or GFCI breakers?

Have you tried putting a clamp meter on the lines going to the breakers and see what the loads are?

If it has a min/max option, leave it on for a couple days and see what the max load is. Maybe another unit has some loads connected to your panel.

 

[mobiledynamics]

Hi Wylie -

It's a Siemens panel and or at least Siemans breakers in a commercial building.

I'm not the spark, but the load is less is using 1/6 of the rated breaker/wire.
Direct runs to the panel/brand new wire/breaker.

On the most recent incident, I watched as they opened up the panel. No other breakers were tripped so it's not like the entire panel with all tripped breakers

No afci or gfci.

When I say three phase, I was asking the spark, let's look at the 2 tripped breakers today just to see if they were on phase leg 1 or 2....and per the wiring color schedule he was counting down, he said they were not as the 220 that tripped was on *b/r*, and the other 120 that tripped he said on the 3rd leg - wire color blue.

 

[wyliesdiesels]

what type of 3 phase do you have?

 

[Milton Shaw]

If its an office with floor outlets under desks then check them for something loose and being kicked or hit by office chair rollers. I have seen boxes knocked loose by just rolling the chair into the desk opening. Also saw cords half pulled out shorting against stainless cover plates when kicked.

 

[mobiledynamics]

In all honesty, WD, I don't know what 3 phase it is. I don't like anybody standing behind me when I'm working, so I was more like 8-10 feet away from the spark/panel when I asked him the ? re: are both tripped breakers on the same leg, and he just pointed out the 220 was on leg 1/2 and then he mentioned that the 2nd breaker is on the 3rd leg, stating the blue wire feeding the breaker.

Milton - these are new direct dedicated homeruns, so it's not shared...

As per the OP, the 1st time this occured, I chalked it up to a weird issue. Since it's occured more than once now, then it's clearly something that needs to a issue and not a ~conincidence~

Post #14, need to re-read it for better clarity

 

[wyliesdiesels]

What is the voltage measure line to line?

If 208v then its 208Y/120 service.

If 240v then its 120/240 delta service with a 208v line to neutral stinger leg

 

[mobiledynamics]

Wylie. You lost me @ hello ;-)

My electrical knowledge only goes so far. Based on post #15, any chance you can shed some light on what might be triggering it...

Since the 2nd time it occured, I have not followed up with the spark to come back and really deep dive diag. the line. He literally asked me if I was ok plugging in the equipment back into of the ones that trips, and he would replace the entire wire run should it occur for a 3rd time. I told him I was not going to plug the equipment back in into there was some level of root cause diag and recourse to follow...

So one of them has sat unutilized....