Light bulbs and transformers.

[Chamuit]

I have a house where the life of light bulbs (aka lamps) is short lived. No other items seem to be affected.

However, I recently installed low voltage lighting in the master suite and have had to replace 3 transformers on (Liton) LH1499 cans.

I am suspecting that there is some kind of voltage issue here. The lights are on different circuits and fed off of different panels so I do not think that shared neutrals are the problem. Two low-voltage xfmrs were on one panel and the third off of another.

I have thought about purchasing an Ideal 61-830 to track the voltage. Any other ideas or better methods?

 

[hurk27]

No light getting brighter, dimming? that would a sign of a bad neutral, what was the voltage you mesured? hot to hot at the panel will tell you if you have a high transformer output or wrongly tapped transformer, if primary is a Y and this house transformer is a hot to neutral primary and theres a lost MGN neutral somewhere back to the sub-station, this transformer would have a high output, or a couple turns in the primary shorted will also do the samething, but your 240 will read high, like 270-280v, other then that high transents will cause lamps to blow, and if these power supplys are electronic then this would explain that too, any welders being used? large motor loads?

 

[gar]

110224-0011 EST

Do you have a decent DVM that resolves 0.1 V at 240 V? Do some voltage measurements. Line to line, and each line to neutral. Out on a circuit where a bulb has failed measure the voltage from neutral to EGC. Do this with and without a 1500 W heater load in that area.

As a wild guess I might suspect a neutral problem anywhere from the transformer to somewhere in the house. If there is a neutral problem, then some lights should dim and others brighten if they are on opposite phases.

Likely to require substantial excess voltage to fail transformers. Up to about 130 V on a nominal 120 V transformer probably won't cause damage on a well engineered transformer.

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[SG-1]

Do you have a DMM with a MIN/MAX function ? You can plug it into an offending circuit and let it monitor for a few hours or days, it will record the lowest & highest voltages during the time period. You will not know when or for how long, only that it was.

Are these incandesent or CFL lamps ?

My POCO transformer windings were slowing shorting out & raising my secondary voltage. Incandesent lamps would go out with a big flash when energized. There was some AM or FM radio interference from time to time also. Some times the voltage would go over 250 L-L slightly.

 

[G._S._Ohm]

I have a house where the life of light bulbs (aka lamps) is short lived. No other items seem to be affected.

The life of incands depends on the voltage to the 12th power or so, so they are the canaries in the coal mine for over voltage issues.