Condo unit with tripping main breaker

[bjp_ne_elec]

Got a call today - local condo complex has the local utility show up during New Years Eve feastivities and determines the issue isn't on their end. They tell the staggering occupants how to reset the breaker if it goes again. I'm thinking, I wouldn't be giving that advice. First they never mentioned to shut down all the mains on the eight section OCP protected units from the outdoor meter distribution panel. Not a good idea to be turning this on without shutting down most of the load - especially not even knowing why the breaker is even tripping (loose connection, overloaded leg, defective breaker, etc, etc).

Well first of all I get called in and there is no labeling in the enclosure and the only thing I can make out on one of the breakers it "ITE". Call the local ITE distributor to find out he's not even open.

As I'm used to doing mostly new work - but branching in to more and more service work - due to there isn't much new work going on. I've never wired one of these "multi-meter socket/multi-breaker distribution panels (if that's the correct term) so this is all new to me and I'm looking to my friends and fellow ECs and JWs to help me out. This main breaker is in a seperate WP (and I use that term loosely as I found the weatherstrip that runs the perimeter of the inside of the box to be sagged so one corner isn't even fuctioning) enclosure. With this breaker inside - actually has a little extension handle that I found sitting in the bottom of the enclosure. How "safe" is it to pull the cover - it's basically two screws that sit at the bottom, and up top there are just two little tabs where the top of the cover sits behind it to stop the cover from tipping forward. No other screws. I was leary of pulling this as it comes right from the secondary side of a pad mounted transformer.

I'm guessing this thing is probably a 1000A or larger - each unit has a 200A main in this outside distribution set up. I was surprised that no amerage was listed on the handle - but I checked several other units.

Talk to the condo associations local rep and ask if there are any blueprints, drawings - anything that might have some Part Numbers listed or a line diagram of the distribution. I get a blank stare.

So the only way I'm even going to have a shot at finding out more info is to pull the inside cover - and I'm looking to see how safe that is. I'm thinking the face of the breaker behind this metal cover would stop the panel from going inward - but I'm not absolutely sure.

So who out there has worked on an ITE panel of this type and what should I be looking for?

Also, as long as I'm learning, I flipped open the little WP (and I use this loosely as well , as not one of them is latched, so the seal isn't even have a chance to perform the function it was intended for) and oddly find a 4-pole breaker. If someone was looking at me at that exact moment - they would have seen my blank stare. So guys, what's this 4-pole?

Thanks

 

[charlie k.]

BJP, I am going out on a limb here, The 4 pole breaker is probally a paralleled 2 pole breaker.
Each pole being half of the rating of the breaker. Thinking back Siemens was famous for this. A 2pole 400 amp breaker was made up of 4 200 amp breakers. If the large main is tripping dont rule out one unit (condo). Check aic ratings on the breakers you may find no coordination. ie 20k on individual condos and 15k on the building main. If everything looks good there suit up and start removing covers. Look for loose connections and discoloration at terminations. An infrared thermometer would come in handy as you look for hot spots. Next do a check of individual currents on all sub feeds as well as the main, they should add up. Hope this helps.

Charlie

 

[Buck Parrish]

I agree with Charlie. I have a couple of those main breakers in the truck for spares. ITE and GE make a single phase 200 amp main breaker that fits on 4 connections of the main bus bar.
These some times go bad , too.
And if water is directly dripping on them it will ruin the internal spring loaded trip mechanism. It will turn in to a glob of rust.

 

[bjp_ne_elec]

How many units in the condo?

Sorry - thought I mentioned it. It's eight units per complex, and this main breaker sits on the left of the eight meter socket/eight 200A breaker distribution center.

I will also mention that I checked some of the other main breaker WP enclosures and noticed that they didn't have ITE on the end of the handle - so my guess is that some have already been replaced. All the WP enclosures look identical - and have almost as many coats of paint as the walls at Fenway (Iwire will get this one).

 

[chris kennedy]

I'm guessing this thing is probably a 1000A or larger - each unit has a 200A main in this outside distribution set up. I was surprised that no amerage was listed on the handle - but I checked several other units.

How many and what size are the conductors feeding this?

 

[charlietuna]

From what you have stated--I would suggest you find a qualified service contractor to handle this problem. True, the load during the new years holiday may(?) have exceeded the main breaker's trip point. It may be adjustible? But someone needs to determine just how close the total load is which means setting up a data logger for a period of time. Just my $.02

 

[bjp_ne_elec]

How many and what size are the conductors feeding this?

Chris - I haven't pulled the cover that is over around the main breaker to determine that. That's what I was saying in the body of the post - as I'm not familiar with how this particular manufacturer's gear is put together.

 

[bjp_ne_elec]

From what you have stated--I would suggest you find a qualified service contractor to handle this problem. True, the load during the new years holiday may(?) have exceeded the main breaker's trip point. It may be adjustible? But someone needs to determine just how close the total load is which means setting up a data logger for a period of time. Just my $.02

Charlie - I like your suggestion, but I'm trying to turn myself in to a qualified service contractor - and how else to do it but tackle new challenges. Most of my experience is new construction, and my strong suit - but I need to grow.

 

[tonyou812]

I bet its water damage to the breaker. I recently pulled one out of a Hooters that was periodically tripping for about a month. The basement was damp and the doors to the cabinet that housed this breaker looked like they dont close anymore.

 

[bjp_ne_elec]

Just to add a little more info - they indicated the breaker was still tripping on today, and most of the folks were not at the complex. So it wasn't the increased demand when all the partying was going on - it's happening under normal useage - and with only one car in the parking lot. This should mean no washers or dryers going - should.

 

[active1]

Is this the style curcuit breaker your talking about?

http://images.google.com/imgres?img...t+breaker&start=126&ndsp=18&hl=en&rls=en&sa=N

I would see them in old and new Siemens, Murry, and ITE pannels until a few years ago. One reason or advantage for the change advertised is the newer style flips sideways instead of up and down making it acceptable by the manufacture to mount the panel upside down. I believe they were tring to get away from the plug in main breakers.

It sounds like your not sure or comfortable doing the job maybe it would be better to pass on it.

 

[bjp_ne_elec]

It looks more like this:

http://www.oodle.com/detail/Ite-100...-Breaker-1200-Amp-Mp-Frame/1106213901/toccoa/

The handle on this one looks identical to the one I see through the metal cover - but keep in mind, I haven't seen the whole breaker.

 

[hillbilly1]

Being that it looks like it's getting water in there, I agree with the others it's probably corroded and rusty. When it was reset, one or more of the blades may have not fully seated, causing a high resistance connection that is heating up and causing the thermal trip to activate. sometimes you can use an infrared thermometer to see hotter than average parts of the breaker. Even bad connections to the bus can cause the breaker to trip due to transfered heat.

 

[mxslick]

I was leary of pulling this as it comes right from the secondary side of a pad mounted transformer.

Do NOT, I repeat, DO NOT attempt to mess with or inspect this breaker unless you can get the poco to kill power to it!! In my cinema work these breakers are common and I have personally seen more than one of them fail violently.

Under the conditions you described and with what others have posted, that breaker is shot and most likely has water damage. The constant tripping under light loaading leads me to believe there is a serious internal fault developing.

While it is noble and great that you wish to expand your knowledge, this is one situation where you'd best be an observer.

Unless you have fully rated arc flash PPE (moon suit), being so close to the padmount you'd best leave it to someone with experience.

It would be most unfortunate to end up reading about you in the papers..as a burn victim or worse.

 

[charlietuna]

I agree with MX! Do you have an idea what fault current that pad mount transformer can produce??? It can blow a hole in the front of that switchgear big enough to push a wheelbarrel through if the breaker goes phase to phase -- i have seen it ! Also understand some main breaker cover plates are interlocked to trip if removed ??? Do you want to be removing this plate when the breaker trips under load?? And what are you gonna do when you have access to the breaker ?? Do you have recorder equipment?? It's fine to learn the trade but do it safely!

 

[satcom]

I agree with MX! Do you have an idea what fault current that pad mount transformer can produce??? It can blow a hole in the front of that switchgear big enough to push a wheelbarrel through if the breaker goes phase to phase -- i have seen it ! Also understand some main breaker cover plates are interlocked to trip if removed ??? Do you want to be removing this plate when the breaker trips under load?? And what are you gonna do when you have access to the breaker ?? Do you have recorder equipment?? It's fine to learn the trade but do it safely!

It says Master Electrician, in his profile, I would like to know what state licenses a Master that does not understand the extreme danger in fault current, that situation can produce. I also can't believe the 5 plus years of training it took to reach master level, din't cover fault dangers

 

[peter d]

I also can't believe the 5 plus years of training it took to reach master level, din't cover fault dangers

I believe it based on the number of electricians I've seen or heard about who will dive into a 480 volt panel live without the slightest idea of the danger present.

 

[Buck Parrish]

Bjp,
Call the poco, have them turn off the power. Then open the main get the style and number off the breaker. Then put the cover on have the poco turn it back on.
Then go get the breaker have the poco come out turn the power off. Get a permit, Put the new breaker in, call inspections have the poco turn it back on. Maybe in a different order.
You should test the Main cables on the load side of the breaker, too. Just to make sure the problem is not there. You may have a lug melting inside that panel. If this set up is on a wood wall. It could cause a fire. This is some thing that should be fixed right away.
Ideally to get the number off of the panel for the breaker . Then get it. So the poco can do it all in one trip.
Maybe somebody at the local supply house can ride over and tell what kind it is. So they can order one.
That breaker might be as high as $1200.00

 

[Fulthrotl]

It looks more like this:

http://www.oodle.com/detail/Ite-100...-Breaker-1200-Amp-Mp-Frame/1106213901/toccoa/

The handle on this one looks identical to the one I see through the metal cover - but keep in mind, I haven't seen the whole breaker.

keep it that way until the power is off.

i'm gonna speak in generalities here... none of us have accurate
information, including you, and there lies the rub.

i have a bunch of old ite moulded case cb's that look a lot like what
you have there.... most of them are ancient, and have interrupting
ratings along the line of 20k.

if you have a fossil 1000 amp breaker, it probably has a rating something
like that. the upstream transformer probably has 40k amps available,
or even higher. if you fault it, it's going to be a film at eleven sort of
thing. the breaker may not have enough interrupting capacity for
the service if it is really old, and the service transformer has been
upgraded, as often happens.

if it's wet, or rusty, all bets are off, and it sounds like that's what's
going on, or something similar.

have the power downed, and with the gear cold, remove the covers,
take photos, write down all information, measure breaker lug centerlines,
and physical demensions, note lugs, and with all the subpanels
turned off, megger the load side of the main breaker, both opened
and closed. that should tell you if it's safe to re energize after you
put the covers back on the gear. even if it meggers ok, it's still iffy,
based on the nuisance tripping. catastrophic failure doesn't always
have telltale signs beforehand.

if you don't have the arc suit, leave this one for the next guy.
a 40 calorie suit, with all the bells and whistles, is about $1,250.
takes a week to 10 days to get one from salsbury.

ANYBODY opening or closing this breaker should be wearing arc fault
protection!

there's people here who've done this stuff way more than i have, but
i've done it enough to know when to play 'em and when to fold 'em.

i think i'd leave this one alone. not judging your ability or intelligence,
but if you haven't got the PPE to go in the shark tank, swimming isn't
a good idea.....

 

[slect]

If you want to be in service as opposed to new work you have to get comfortable pulling off the covers and dead fronts. No other way. You must visually inspect for water damage, discoloration, or melting or burning insulation on the phase conductors. Sounds like a faulty breaker. Replace it.
If there is additional damage to the enclosure sell them an entire new meter module. And don't give it away ! Good luck