Candy stripping HO Fixtures and Ballast Failures.

[Riverkid]

I had 21 HO Fixtures installed about 20 months ago on the exterior of a Drive thru store.
Seven Fixtures were placed on one side in a continious fashion, on a timed switch. I have not had to replace a bulb or a ballast on that circuit. However, the electrician installed the other 14 fixtures on two sides of the building in a strip fashion but wired the units in a candy strip fashion placing oppisite phases of the 110 source on any two fixtures. I have had to replace to date 8 ballasts and 32 lamps in these two sides of the building. The ballast are failing in pairs as well as the lamps. To me this is a no brainer. Re wire the Fixtures so only like phases of source power is resident any adjusant fixture. However the City electrical inspector has advised the owner the wiring of oppisite phase fixtures will not cause this high failure rate. I'm putting this out to the best of you all. Help

 

[don_resqcapt19]

Look for a problem with the neutral.

 

[tshea]

Re: Candy stripping HO Fixtures and Ballast Failures.

However the City electrical inspector has advised the owner the wiring of oppisite phase fixtures will not cause this high failure rate.

The inspector is a contractor????

 

[Riverkid]

No just a City Employed Inspector. I will check for conditions of a floating nuetral however my gut experience with video monitors in matrix configurations which one cannot operate on opposite phase powering leads me to believe, since the fixtures bulb connectors which are butted against each other, is the problem as the ballasts which are failing have been next to each other physically. As there is no physical seperation of the fixtures Bulb holders this is leading me to believe sheath currents are responsible for the failures.

 

[peteo]

Welcome to the forum. The family was in and around Portsmouth from 1800 to 1930, if you know someone who's into genealogy PM me.
Don has much more knowledge than I do, and it makes sense that any problem with the electric neutral would be the fault.
From what I understand, the failing fixtures have been tandem wired (inline or strip tandem,) with a particular fixture's bulbs wired from two fixture's ballasts. If so, I can understand how you would be concerned. To quote an old textbook, HO lamps must be mounted within 1 inch of grounded metal extending the full length of the lamp. If there's nothing wrong with the neutral (step 1) you can call the fixture or ballast maker's phone help line to speak with a specalist in their product. Please post what you've found.

 

[catchtwentytwo]

Re: Candy stripping HO Fixtures and Ballast Failures.

However, the electrician installed the other 14 fixtures on two sides of the building in a strip fashion but wired the units in a candy strip fashion placing oppisite phases of the 110 source on any two fixtures. I have had to replace to date 8 ballasts and 32 lamps in these two sides of the building.

Are the fixtures, lamps and ballasts all of the same brand? If they are, were they all purchased at the same time? Look for date codes or serial numbers

All major ballast and lamp manufacturers have technical support departments (try the company web site for an email address or toll-free number). They may have seen a similar problem or have had a QC problem.

If the ballasts are an "off-shore brand", you're probably out of luck