Why deliberately shorting equipment to blow breakers might be a bad idea . . .

tragedy suggests safer constrction codes.

"Gov. Matt Blunt on Friday proposed a sprinkler system mandate for Missouri's long-term care facilities in response to a fire that killed

Robert Green wrote:

If everything is "to code", aside from the personal hazard to the one doing the shorting, this practice should be completely safe.

But the consequences of something being amiss (not to code, poorly done wiring, etc) and causing a fire, with damage or worse, is too high a consequence to pay for a little convenience.

Its a classic "low risk of occurrence, high cost of occurrence" scenario.

Dave

All it takes is some idiot doing this and the next NEC will require GFC, and arc faults for everything.

...

Something seems left out here. As you say, unless there's another fault, there really is no reason this should cause any problem whatsoever -- how does the breaker or rest of the circuit "know" it was a deliberate act as opposed to accidental or a faulty piece of equipment plugged into an outlet or a ground fault developed in the furnace blower motor? All the breaker was supposed to do was trip to remove the fault condition. Did it not do so? If it did, how was there an "overload" in a dead circuit? Was the breaker over-sized for the branch wiring?

The fundamental fault appears more deeply embedded and the consequence could just as easily have occurred had there been another causative action so I think faulting the maintenance worker unless he left an undersized jumper in place or some other action other than simply causing the short seems short-sighted -- finding the underlying fault that then caused the result should be the focus of investigation, not simply a person to point blame at. Then again, if he was smoking at the same time, too, and dropped the end of his cigarette in the attice w/ onto something flammable beside the location he got access to the wiring to make the short...

In all, I think there's more to the story still untold...

The local news made mention that there was a poor (inproper) splice on the circuit (in the attic) and theory is that shorting the circuit, while it tripped the breaker, was likely the cause of the fire.

This was early on in the investigation, and I only heard it mentioned once. I live about 50 miles from the home and we had a lot of TV coverage of this fire - a real tragedy. I was an electrician for 30+ years and never felt this method of finding which breaker controlled a circuit was wise, but then I still believe fuses are more reliable than circuit breakers, so what do I know ;-)

That at least makes some sense -- see my previous comment. More than likely in this case there was a high resistance at that point and may have well been operating at nearly the combustion point for quite some time. The actual action only shortened the time until it would have happened "spontaneously" in high likelihood if that were the case.

I really still don't see the difference between the accidental and deliberate short as a fundamental problem. I don't much like the practice as it just doesn't seem "right" somehow, but fundamentally it requires the second fault for a problem to occur. It may, as in this case, uncover a hidden fault with bad consequences, but that still is a fault separate and the event being overt instead of covert is only circumstantial.

Interestingly enough, I had a hot tub -- 220 volt, GFI in the basement. If there was a fault - motor overload, etc., it seemed to deliberately shut itself down by causing a "short."

Hey it worked in the dorm (mumble mumble years ago) to silence the neighbors' stereo on the same circuit. LOL

Just wanted to note I wasn't trying to support this practice in any way- it's never responsible to commit an act that might endanger others unless every last thing is perfect.

Dave

It also works well on a coax silencing an annoying character's CB radio with illegal linear amplifier. "Blown finals" does not necessarily refer to exams. :^)

Then what the Hell good are the circuit breakers?

The problem occurrs when there is some part of the system between the shorting-point and the breaker that is not up to code.

Dave

Unless, while specified to code, the breaker panel is one that tolerates currents grossly in excess of the nominal capacity of the breakers.

(Our house had an untrippable Zinsco panel when we bought it.)

...

But if that is the case (as at least one poster has said was reported in the subject event), it's also the case whether the short is induced intentionally or not and so it isn't the shorting that's the fundamental problem but the other fault. If the intentional short causes a catastrophic problem, it's highly likely an unintentional one will, too.

Good info. I was always told, never intentially create a makeshift fault to test a protective device, because it might only be designed to work once, or it might fail badly, and never work right ever again. Creating a dangerious situation.

Always use 'approved' techniques, test buttons, etc. Oh and only use qualified electricians. ;)

tom @

Yes, that's a given.

Would it be morally wrong to short outlets during a home inspection?

Dave

Well, breakers that don't break when they're supposed to is a fault in itself!

Exactly the kind of occurrence that makes me say 'never do this', because it requires a chain of wires/splices/devices that ALL have to be perfect for this to be 'safe'.

Dave

Imagine how many more people might have died if the fire had occurred from an unintentional fault. Maybe no one would have died if it had never been shorted, but there was obviously a deeper problem than an electrician with a screwdriver.

But unless that condition is true, it isn't "safe" anyway, so it's a false comfort at best...

Well I am the poster who checks breakers by shorting:(

First I turn OFF the breaker!

Then I check its dead with a test lamp or meter!

Then I short it intentionally just in case!

Over the years this method has saved me from some possibly nasty shocks:)

I have discovered boxes fed with multiple power sources in one box, never a good idea if you ask me......

I have also discovered some bad breakers that didnt trip under full short. On these I replaced all the breakers in the panel

Also leared FPE stab lock breakers are a known fire hazard......

I dont believe theres a difference between a intential or accidental short, the breakers should trip either way. 100% of the time. and become more sensitive to overloads as they age.....

For good reasons soon ALL receptables will be GFCI and arc fault protected