Porch Light Bulbs Failing

The claim is part accurate but not good for light bulb as it is a non loaded resistive device.

A motor will try to do a certian amount of work and as the voltage lowers it will draw more amps but if the lowering voltage is due to a poor connection then the amps may be limited but this causes yet lower voltage and if the current flow is such that the motor still operates it can get damaged.

DC plants on battery do same where as battery voltage drops the regulated equipment draw more amps due to lower voltage to produce same work...power is same but inputs vary...volts lower and amps higher but watts constant.

The op likely has a bad neutral and there are cases where some electrical folks have used creative wiring where they use 2 hots at 240 and single neutral to save a wire as it meets load and code but a poor connection to the neutral in that circuit can make that circuit go wonky and let the rest be fine.

Suggest checking voltage at the fixture and if not wanting to open it up get a 2 bulb adaptor or screw in adaptor to cord which would allow measurement and testing.

After unloaded voltage measured next install large watt bulb of if cord adaptor used plug in hair dryer and measure voltage under load.

If it drops much then you may have a bad neutral which requires some trouble shooting with a voltmeter checking both hot and neutral voltage to other outlets and fixtures and the extension cord makes this easier.

Sent from my SAMSUNG-SGH-I337Z using Tapatalk
 
Redoing the connection from the solid house wires to the stranded fixture wires seems to have fixed the problem.
 
Vibration causes incandescent bulbs to fail. Has anything changed at the location that would cause the bulb to be exposed to more vibration? A few years ago we replaced our heat pump and a pedestal light in our family room started burning out bulbs. It was located over the main HVAC trunk. Vibration from the new system was causing the bulbs to fail.
 
Glad you found a fix. Our house was located close to the neighborhood transformer which has a loose tap. I am told that cause the voltage to drop and peak rapidly. Whatever, we ate bulbs until that transformer was replaced or re-tapped. Richardson would have old transformers as does Plano - it is also likely your house has some of the Federal breakers that are notoriously bad.
 
Nope, no Federal breakers in my house.
It's been a year or so and I've had no more problems with the porch light. The bad connection seems to have been the culprit.
 
2 houses, both identical expensive american made lamps. same problem. at present 2 on gate, one on driveway. chinese incandescent lamps last from one day to about a month - no matter the brand. same with identical lamps on prior house. there are no electrical problems. and led bulbs are not compatible with the photocell in these fixtures

on shop 2 american made outside industrial fixtures. led bulbs. one has been running almost 2 years, the other just blew (little over 2 years)

when i get time i am switching out the photocells and putting in leds in the other lamps
 
could be the lamp socket is loose allowing the bulb to shake and jar in the wind or when the door is closed hard.
 
Could be the triac in the motion sensor device used to switch on and off the power to the light is problematic. Triacs conduct in all four quadrants, but if there is defect such that one or more of the quadrant "switches" is not working, then you could be work hardening the filament - resulting in premature failure. The triacs in these devices are the business end and what typically fails first. Generally, triacs fail to short, and a total failure usually results in the load being on all the time. If you are handy, pull the triac and test, or just simply replace the triac. In my devices, I simply toss and replace the whole motion sensor device but retain the bulb fixture. On another note, someone mentioned suffering premature failures with LED devices. This most often occurs where the LED is fed from a dimmable control intended for an incandescent (triac) rather than something else like a PWM type of control.
 
Back
Top