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#74625 01/28/07 10:01 PM
Joined: Oct 2005
Posts: 10
redneck Offline OP
Customer has complaint. He has recessed lights in the bathroom,and when the bulb blows,it trips the breaker. Bulbs are Halogen,120v,Sylvania double life,Capsylite Par 20.

Doesn't happen often,maybe a couple times a year. Breaker only trips when the bulb blows. Standard breaker,not GFCI,and lights are on separate circuit from Receps in Bath.

We didn't do the job,but he called me wondering what it could be.

Any ideas?????


Joined: Jun 2005
Posts: 821
If the circuit breaker is tripping it can only be one of three things: an overload, a short circuit, or a ground fault.

Joined: Jul 2004
Posts: 787
Breaker trips also include physical shock, strong magnetic field, and over temperature.

I tend to doubt that any of these, are in fact the cause of this behavior.


Joined: Feb 2003
Posts: 939
there is good chance when the filment break it will delope a arc current like HID for a split sec that just enough to trip the breaker

that one possiblty i can think of

Merci , Marc

Pas de problme,il marche n'est-ce pas?"(No problem, it works doesn't it?)

Joined: Dec 2005
Posts: 869
Likes: 4
Check the loading on the circuit concerned.
If say for example a 16 Amp beaker runs at 14 Amps lighting load, the cold inrush current from all the lamps and the arc from the lamp failing may be just enough to trip the braker.

Is it always the same lampfitting or all over the place ?

The product of rotation, excitation and flux produces electricty.
Joined: Feb 2002
Posts: 22
I have a fixture (outdoor floodlight) with halogen bulbs (stab in, not screw in) and it (apparently) tripped the breaker when one the bulbs blew. I noticed that other lights (inside the garage) on the same breaker were not on, so I reset the breaker and found that the only thing amiss, at least that I could tell, was the blown bulb in the floodlight.

Joined: Sep 2006
Posts: 26
I have two 90 watt PAR 40 halogen floodlight bulbs in an outdoor light fixture. Every time a bulb burns out, it trips the 15 amp breaker. I wrote General Elecric lighting department asking their opinions on this, and all they did was send me an apology and a case of new flood bulbs.

Joined: Jul 2004
Posts: 625
I'm thinking a breaker rated "HACR" might be a good workaround, if that's not what's already there. They would be more likely to hold while the lamp filament clears, but will still adequately protect the wiring.

Joined: Jan 2006
Posts: 558
I remember back in my school days every time an overhead projector would burn out a lamp it almost always would trip the breaker. The breakers were Sq-D and located right in the room so it was not too troublesome to reset actually.


Joined: Oct 2000
Posts: 2,722
Likes: 1
Broom Pusher and
Marc hit the nail on the head!

Halogen Lamps have what is known as "The Halogen Cycle", which should be known for extended Lamp Life.

Simply put, to get the most life out of the Lamp, keep it as Horizontally Level as possible (+/- 4°).
This causes the Atomized Fillament to land back on the Filament, during operation.

When the Filament fails under load, the Atomized material allows an arc to be sustained, and the Arc has no Resistance (actually has negative resistance) - so there is a large increase in load current, which trips the breaker.

Same would occur if any Non-Ballasted Discharge Lamp was thrown across the line.


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!
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