Electrical Inspection — Is AC inspected independent of DC?
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Secondly in cold climates a problem arises. Forget which city in Wisconsin converted all traffic lighting to LED, and school buses to run Vegetable oil aka bio-diesel. Worked great until winter hit. The bio-diesel congealed in the tanks and fuel lines rendering them useless, and Traffic lights were caked in layers of ice and snow so no one could see them. They had to tow all buses to a heated warehouse to thaw out to clear fuel in tanks and lines. Schools were closed for a week.
Then the city had to switch back to incandescent lamps to melt the snow and ice and keep it off as the incandescent lights generate heat.
Oops!MSEE, PEComment
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Energy conservation is not the primary reason, just a side benefit. The driving force is maintenance cost.
Secondly in cold climates a problem arises. Forget which city in Wisconsin converted all traffic lighting to LED, and school buses to run Vegetable oil aka bio-diesel. Worked great until winter hit. The bio-diesel congealed in the tanks and fuel lines rendering them useless, and Traffic lights were caked in layers of ice and snow so no one could see them. They had to tow all buses to a heated warehouse to thaw out to clear fuel in tanks and lines. Schools were closed for a week.
Then the city had to switch back to incandescent lamps to melt the snow and ice and keep it off as the incandescent lights generate heat.
Oops!
As for the stoplights - they definitely have had issues that the new lights were too efficient - so weren't warm enough for melting off hard blowing snow. But the articles I recall seeing about Madison they didn't switch back to incandescents - instead they changed the sun-shade thingy so the snow wouldn't accumulate. This isn't the one I saw back then - but similar content: http://abcnews.go.com/GMA/ConsumerNe...ory?id=9506449Comment
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I do not know of any large cold warehouses that are warm, regardless of the area. I would hope not damp though.
And FWIW, some rooms in my house get well below 50 in the winter. And when I do into them I want the lights to work well. (Although it might also be nice if the lights gave off some heat too!)SunnyBoy 3000 US, 18 BP Solar 175B panels.Comment
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That was in reference to the immediately preceding statement about LEDs being better for "lighting in parking lots, roadways and large cold warehouses. "
I do not know of any large cold warehouses that are warm, regardless of the area. I would hope not damp though.
And FWIW, some rooms in my house get well below 50 in the winter. And when I do into them I want the lights to work well. (Although it might also be nice if the lights gave off some heat too!)
Turns out that the cold (38F) storage was not a good environment for these lights. They were also installed in our dry ambient warehouses and work like a charm.Comment
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Umm, so I have some catching up to do here.
It's entirely possible I misunderstood about the use of straight up DC for LED lighting, but I am certain that I got the part about LED conversions correct. Seems like LED for big lighting has become quite popular in Alaska. Although as CA_Tom points out, interesting possible downside to a light source which stays cool and doesn't melt off snow.
So maybe the origin of advice I got about using DC power for economy is something that doesn't scale — cost savings result if used in large quantity, but for a residence, not significantly.
But I did get a few solid answers today during my rough electrical inspection, which I went ahead with, figuring that getting the inspector's eyes on the project now would be worth the $90 it will cost to have him come by again.
Turns out that everything that was wired for DC is wrong, and I need to run all that wire again if I want to keep DC outlets and lighting.
So now I have an opportunity to decide if I will stubbornly keep some DC, and pull new wire. Or will I just use the AC and remove all trace of DC wiring that is there.
FWIW, I also learned that all my breakers need to be Arc Fault (AFCI), as of July 1st. So I will be making that change, too.
My location, which I was vague about, is roughly 48.8° N, 118° W. Fun fact: our 2010 census population is 28.Comment
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I have heard of people using AFCI for inspection and then swapping them out... I do not recommend that though.Comment
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In Washington State, for permits pulled before July 1, 2014 AFCI protection requirement was limited to the bedrooms. Now it seems to be most rooms of a home with 120, single phase, 15 or 20 amp circuits (except bathrooms??). For areas that previously required only GFCI, my inspector endorses a AFCI breaker plus GFCI protection at the outlet.Comment
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From the Wikipedia - http://en.wikipedia.org/wiki/Arc-fau...it_interrupter
Electrical code requirements[edit]
Starting with the 1999 version of the National Electrical Code (NFPA 70) in the United States, and the 2002 version of the Canadian Electrical Code in Canada (CSA Standard C22.1), the national codes require AFCIs in all circuits that feed outlets in bedrooms of dwelling units. As of the 2014 version of the NEC,[4] combination type AFCI circuit breakers are required on all branch circuits supplying outlets or devices installed in dwelling unit kitchens, family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreation rooms, closets, hallways, laundry areas, or similar rooms or areas. They are also required in dormitory units. This requirement may be accomplished by using either a kind of circuit-breaker (defined by UL 1699) in the breaker panel that provides combined arc-fault and overcurrent protection or by using an OBC AFCI Receptacle for modifications/extensions, as replacement receptacles or in new construction. Not all United States jurisdictions have adopted the AFCI requirements of the NEC as written so it is important to check local Code requirements.
The AFCI is intended to prevent fire from arcs. AFCI circuit breakers are designed to meet one of two standards as specified by UL 1699: "branch" type or "combination" type (note: the Canadian Electrical Code uses different terminology but similar technical requirements). A branch type AFCI trips on 75 amperes of arcing current from the line wire to either the neutral or ground wire. A combination type adds series arcing detection to branch type performance. Combination type AFCIs trip on 5 amperes of series arcing.
The advanced electronics inside an AFCI breaker detect sudden bursts of electric current in milliseconds; long before a standard circuit breaker or fuse would trip. A "combination AFCI breaker" will provide protection against parallel arcing (line to neutral), series arcing (a loose, broken, or otherwise high resistance segment in a single line), ground arcing (from line, or neutral, to ground), overload protection and short circuit protection.
OBC AFCI Receptacles contain electronic components within the device that constantly monitor a circuit for the presence of “normal” and “dangerous” arcing conditions. Based upon an established threshold in the sine wave, the AFCI can be triggered to quickly react and de-power a circuit if “dangerous” arcing is detected.
In 2002, the NEC removed the word "receptacle", leaving "outlets", with the effect that lights and other wired-in devices such as ceiling fans within bedrooms of dwellings were added to the requirement. The 2005 code made it clearer that all outlets must be protected despite discussion in the code-making panel about excluding bedroom smoke detectors from the requirement. "Outlets" as defined in the NEC includes receptacles, light fixtures and smoke alarms, amongst other things — basically, any point where electricity is used to power something is an outlet.
As of January 2008, only "combination type" AFCIs will meet the NEC requirement. The 2008 NEC requires the installation of combination-type AFCIs in all 15 and 20 ampere residential circuits with the exception of laundries, kitchens, bathrooms, garages and unfinished basements.[SIGPIC][/SIGPIC]Comment
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In Washington State, for permits pulled before July 1, 2014 AFCI protection requirement was limited to the bedrooms. Now it seems to be most rooms of a home with 120, single phase, 15 or 20 amp circuits (except bathrooms??). For areas that previously required only GFCI, my inspector endorses a AFCI breaker plus GFCI protection at the outlet.
One more thing for you to think about if fire hazard really concerns you. Give up the idea of low voltage DC as you are just asking for a fire. That is why you *** got whacked by the inspector. He knows it is dangerous and you did not follow the code to compensate for the added danger.MSEE, PEComment
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Today we pulled out all the DC wiring, and replaced it with good ole regular Romex. Tomorrow, I will go on a hunt for some arc fault breakers, since no one locally has them in stock — if they even know what they are. I am aiming to pass a do-over rough inspection next Tuesday.
Thank you all for chiming in with such an array of information. I'm actually kind of excited about learning so much; good background for when I actually start planning the solar power install.Comment
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