ECN Forum Forums General Topics of the Trade General Discussion Area Square D Breaker failure

[quote]Just out of curiousity here, was this a HomeLine series breaker?[\quote]

err ya what did I type.

It's not like this circuit had loose connections all over. I have seen copper burn before and aluminum burn for 40 feet.

Yes, it did go bad immediatly after he worked on it. But still could not nail it down to what he did or why it did not burn downstairs.

This short was between the hot and nuetral not ground.Sitting here looking at some of the receptacles there is no sign of damage to any of the devices. Only to the wiring.

[img] http://www.msnusers.com/Saylor/Documents/electrical%20002.jpg [/img]

I just didn't think u could get as that size of copper that hot that fast. When on a properly sized breaker. It sounds like it was doing the buzz,, short circuiting for some time, how about longer then usual....

maybe the homeowner just did something and is refusing to tell me. He could have tried to fix it himself somewhat befor I arrived and did a cover up.

Neil

[This message has been edited by Bomzin (edited 03-28-2004).]

[deleted]

[This message has been edited by Hutch (edited 03-28-2004).]

i agree with the others that say the homeowner is not telling the whole story. he probably made a stupid mistake and fixed it before you came to save himself embarrassment. feel there is something wrong with the breaker and you wish to contact Sqaure D but you want to tell them EXACTLY what went on when the breaker failed.

say this to the homeowner "this breaker may be defecteve and Square D needs to know exactly what occurred when the breaker failed. If it is defective, thousands of people's lives may be at stake and Square D needs to be able to recall the product."

make sure you don't put the owner at fault i.e. "I know you did something wrong and covered it up" that won't get them to talk.

To me, the key observation is that the burning is at the ends, close to the device terminations.

I made a set for a magazine photoshoot that required a failed and burned connection at a receptacle. All I did was plug in a 1400 Watt electric heater and loosen one terminal screw on the side of the receptacle the heater was plugged into. A pinpoint plasma arc appeared and wandered around, smoke billowed and insulation melted, all the while, the heater made heat and the breaker simply didn't care, 'cause the load was within spec. The process was complete for one terminal in about 10 minutes.

The dozen, or better, burned connections in your client's circuit says, to me, that something was left running for a fair chunk of time.

With respect to the photo, you can email it to: Photos@Electrical-Contractor.net
Bill Addiss will place it in the right thread if you send a note along with the photo naming the thread. Your browser address bar will have one name of the thread, for this one: https://www.electrical-contractor.net/ubb/Forum1/HTML/004062.html

[This message has been edited by ElectricAL (edited 03-29-2004).]

This sounds like only one simple and common thing - loose terminations!

What probably happened is the Homeowner plugged in a Portable Heater on the last Receptacle in the 2nd Floor string - where ever the last Receptacle's Outlet box has Barbequed L-N Conductors.

Using the Receptacle's Terminals to make up the circuitry (back-Stabbed, or screwed to screw terminals), the Conductors were likely put in very sloppily - like being tweeked once they entered the pressure terminals.

Used or extremely cheap Receptacles may have been installed, or conductors were pushed into slots which were previously used and the existing wire was removed very poorly.
If the screw terminals were used, they were likely to have not been tightened properly - either left loose, improper conductor wrapping / landing, or they were simply tightened so much they stripped out.

I have to say this because the resulting damage to the Line Circuit Conductors is an apparent result of extreme heat dissipation - the tell-tale signs of a poor termination at the Device.

If wirenuts were used for makeup at each Outlet Box, then the makeup was poor and incorrectly done.
If you have found fried Wirenuts at each splice, and the burnt insulation travels away from the wirenut, that's the culprite.

At the circuit breaker, the termination was likely left loose or stripped out - if even terminated inside the lug properly.
Have seen some frames where the wire did not get landed inside the termination lug, and instead was wedged underneath it with a sufficient pressure as to allow current to flow.
Loading that circuit upto 5 or more Amperes resulted in the smoke leaving the insulation + the breaker's frame.

To wrap this up, it sounds like a High Load, Long Duration, Multiple loose connections scenario.

The Breaker failed because it was probably reset numerous times under an L-N fault condition - plus it was fried from the poor connection.

Check the effected circuit's white wire termination at the panel, to see if that screw is also stripped / loose, or if the end of the wire is also barbequed.

Most likely, you will never get to the bottom of "What Happened / What Did The Homeowner Do To Cause This" by asking directly - only by asking indirectly will you stumble across the real explaination!

Ask about how long the Heater(s) was/were plugged in before the breaker first tripped, and if the heater ran for a long time too.
Hint around as if you have used many old or used Receptacles before, with the back-stab technique and "How Easy They Work" - this is almost a 100% guarantted confession "bait story"
Throw in something in the lines of stripping terminal screws and still using the device "Because It Works Just Fine", and maybe you will be ready for additional clues to "Pop-Up".

Sorry, but this just sounds too much like high, long duration loads with poor terminations. A fault would have resulted in much different scenarios.

There is one other possibility to think of - maybe a larger breaker was used for the first part of the damage - like maybe a 50 amp breaker to "Keep From Turning Off When All 8 Of The Heaters Were Running", and the 15 Amp breaker in place now is just a Scape Goat for the whole thing!
May have even been directly above or below the 50 Amp breaker and became fried from the extreme heat transfer!

Good luck.

Scott35

Scott,


Are you saying that electricians should intentionally spread dangerous misinformation?

In the words of the OP: "Each and every plug upstairs and through the switch's main feed on to the next plug have done a melt down, things just melted to each other causing shorts everywhere."

It seems this would require a high impedance path and the shorts to occur in sequence, starting at the fault furthest from the breaker. Or a bad breaker.

Furthermore:

"Also the wire going to the breaker had also done a meltdown along with neutral."

and

"Sitting here looking at some of the receptacles there is no sign of damage to any of the devices. Only to the wiring."

This doesn't fit the loose terminal theory very well.

Are you sure that there isn't damage to the cable outside the boxes? Even if there is no damage visible from the outside, there could be damage on the inside.

[This message has been edited by C-H (edited 03-29-2004).]

Sorry scott all a nice theorie and all but not buying it. Been there seen that this is not the case.

As for the cable outside the box's all of it was removed. I cut some of it mid point and no sign of damage.

I've been contiplating all day on this with some of the info given here.

Also went back and talked to the wife. Nothing was plugged in. While he was working on it is when it happend. Towards the end of the project. Homeowner has done own electrical work before successfully over the years. Dealing with a couples in there mid 50's probably high school sweeties from the picts I see.

Wife recalls 2 buzzing sounds one short. The other longer possibly 10-15 seconds.

Theory: HomeOwner,<HO>, causes a direct short downstairs, tries it once and shocks the system doing unknown amount of damage to all those push connections on the back of the plugs. HO fiddles with it checks connections he made and re-energized the circuit, here comes the long buzz.

Current should peak here and breaker should trip, but doesn't.Possible damage to the breaker also. Wire heats just enough to melt the unjacketed wires. The jacket may have drawn the heat away, acting like a heat sink along with the plugs. Looking at the plugs they have almost a 1/4 of copper showing on the back of some of the push connectors. But in the same respect they all appeared tight and no sign of burning was observed going into any of the plugs, it all stopped just that 1/4 short of the plug and about the same on the sheathing end.

His final connection he made using the screw connections on the rec. I'm not totally convinced he hooked the plug wrong maybe , maybe not. But he definately damaged something in the proccess. Alot of electricians around here will damage the wire when stripping romex.Just plainly slice into it with there trusty razor knife and fillet it open.

Lets just say something happend didn't find it while I was there. So no way of telling now .


I guess the question now is. Was that breaker operating right at it's maximum potential, just a combinations of some bad luck and semi loose connections.

How many amps does it take to heat 14guage?

Good 'Ol Murphy at work

Neil

Neil,

I may be the only one, but I can't get past MSN's security. Passport.net lets me sign in, then tells me "access forbidden", HTTP Error 403.

Do you still have the photo to send to Photos@Electrical-Contractor.net?

Al

Will send it to web master.
Neil