48 to 12 volt conversion [RE-wrenches]

[Jeff Clearwater]

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Hey Ray and all,

I just wanted to make sure that before we threw 12 V CFs out forever 
based on Ray's assessment that we note that you did say you stopped 
selling them a couple of years ago - no doubt on your experience then 
but perhaps they have improved since then?  2 Amps shouldn't cause 
much heat on the contacts involved.  AEESolar sells a series of 12V 
CFs with a two-year warranty and claim 6000 hours.   Anyone have 
experience with the latest ones from AEESolar or elsewhere?

Jeff C.
Village Power Design


>>Change as much as possible the 12 volt halogen lights
>>to 12 volt Compact Flourecent.
>I'd have to recommend against 12 volt DC compact fluorescents. We 
>have seen almost 50% failure rates and quit selling them a few years 
>ago. My best assessment is that the low voltage high current ( 2 
>amps instead of 0.2 amps) causes the Edison tip of the bulb to heat 
>up if the connection isn't perfect. The heat from the ballast 
>combined with the tip heat takes out the ballast or in several cases 
>melts the plastic around the tip contact. We go to 120 vac CFs as 
>much as possible, even converting all  DC lighting circuits over to 
>AC.
>120 vac CFs are 4 to 5 times cheaper, much easier to get, much more 
>reliable, and use 10 times less current so overheating problems are 
>reduced. Add the special DC rated switches needed for 12 vdc 
>circuits and all that extra copper, more circuits for fewer lights 
>etc. , I'm surprised 12 vdc is so slow to die. Then think about how 
>most 12 v lighting systems are combined with 120 vac, and the very 
>real possibility of someone taking a 12 v bulb (usually unlabeled) 
>and screwing it into a 120 vac fixture.... they can actually blow up 
>showering your customer's face with fine glass. I just don't see the 
>benefit except for tiny non inverter systems.

-- 
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Jeff Clearwater
Village Power Design Associates
Sustainable Energy & Water Solutions for Home & Village
http://www.villagepower.com
gosolar at villagepower.com

530-470-9166
877-SOLARVillage
877-765-2784
425 Nimrod St.
Nevada City, CA 95959
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