Question by Guest_96981375: How much should it cost to change out a ballast in a T8 two-lamp 120V residential fluorescent light fixture?
I several "cloud"" fluorescent light fixtures in my house. One no longer lights at all. The second is very dim but both lamps are lit, and the third will only light one of the two bulbs. I've changed out the bulbs with new ones, but the problem still exists. The light fixtures are about 7 or 8 years old. I'm thinking the ballasts need to be replaced.
Answered by LCD: I presume you have checked the bulb types match the fixture - there are now three types of bulbs with the same ends that will fit different types of fixtures (T8 and T12 are the commonly available ones - don't remember the other type offhand, which is used in industrial applications) - use the wrong bulb type and they will either burn out prematurely, or fail to light fully. Also, some bulb brands are designed for use in only magnetic ballasts, and some only in electronic - which can also cause your problem. I am guessing offhand you might have this mismatch problem - check label on fixture and ballast, then check bulb manufacturer specs on type of ballasts acceptable for the bulbs you have. This actually sounds like it might be your problem, especially since ballasts typically last 20 or more years.
A replacement ballast costs about $10-25 depending on capacity and brand. The bite is that an electrician trip charge (which includes 30 or 60 minutes work) is going to be $75-150 probably - for about 5 minutes work on each light fixture.
If these are ceiling flush mount fixtures (as opposed to recessed or trougher type), which is what it sounds like your case is, you may well be able to buy new ones and install them yourselves as cheap as buying a replacement ballast - or take this chance to change light fixture if you want - and avoid the electrician charge totally. New fixtures also commonly come with bulbs too - making them respectively cheaper. In fact, for some plain fixtures like 4 foot shop lights, a new fixture with bulbs can be cheaper at a box store than just two bulbs alone.
This assumes you have a nominal experience with using wire nuts to connect wires together, and you may need a second person to help hold the fixtures while you disconnect and reconnect them.
To see if it is the ballasts - move the currently working bulb around between all the light positions (with power off while changing out) - if it works where a bulb currently does not, then the ballast is almost certainly OK and the problem is bad or wrong type bulbs.
Answered by jbode: what would it cost to change out a 1000 watt ballest in a light pole. the pole sets at 45 feet in the air.
Answered by LCD: To the questioner on pole-mounted 100W ballast replacement - I can't imagine a flourescent light being pole-mounted for parking lot or street lighting, so I am guessing you are talking a HID (High Intensity Discharge) security large-area coverage lamp, because 1000W is awfully high for a parking lot or street light.
Depending on the lamp type, ballast can run from a low of about $100-150 to about $600 bill-out rate - commonly around $300 plus or minus a hundred or so - plus around $170-300 commonly for a transit-setup-diagnosis or minor repair labor/truck fee for a boom truck and electrician.
So you might ask them if cheaper to replace ballast or to replace the light with a ballast-free light like LED is cheaper. Assuming that and not the light sensor is the problem - sometimes replacing or even just cleaning bird droppings off a photosensor is all it takes to fix it. lso - how do you know it is the ballast. If a light with ignitor capacitor and ballast like high pressure sodium, commonly they start flickering and failing to fully ignite as they reach end of life and it is just the bulb, not the ballast going bad - though let it keep going doing the flickering or continual restart attempt thing and it will take out the ignitor and/or ballast in fairly short order. Or might be the ignitor (capacitor) - but without diagnosing I would not just replace the ballast considering what it costs.
Considering ballast replacement costs (now and every 10-15 years or so maybe) and potentially VERY significant (commonly 2/3 - 3/4) electric savings, changing to a more modern light may save you a LOT of $ in the long run - especially since they (if they meet the claimed life) last the 3-5 times as long as a conventional lamp (though my experience is LED lights typically last 10-15% of claimed life in intermitent on-off type use, maybe 20-30% in overnight use, and only come anywhere near to claimed life in continuous service because the starting electronics fail.
A 300W LED NextGen or equivalent fixture complete with bulb(s) (roughly equivalent lighting to 1000W halide or halogen or HID bulb - plus with better direction lighting you need less total lumen output to provide equivalent light on the target area) commonly run $350-750 range for the fixture complete, plus probably about $300-400 installation (which would include the transit/setupcharge) on many common types of existing pole mountings.
Electrical would be the Search the List category - though Angies List is keyed to home type electrician, so maybe best to google for parking lot light or outdoor lighting repair contractors in your area, then cross-check those names on Angies list to see if they have any ratings/reviews on AL, because you are really looking for a commercial outdoor lighting/electrical contractor, not a normal indoor electrician - both for experience with pole lights and to have the bucket truck needed to access it.
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