Having got all my stuff together to 'lectrify my off-grid cabin in Baja, I've been intrigued with the number of people who have said to wire the cabin
with 12v for lighting and 120v for outlets. At first I thought that was nutz, after all, I had just got an inverter/charger and a 100amp load center
to handle all the 120 v circuits - why do a parallel system?
The argument for 12v lighting goes something like this: with the advent of LEDs, I could wire the cabin with 12/2 (yellow) for the lights and 14/2
(white) for the 120v appliances. The total watts of all the LED light bulbs in the entire cabin is less than 50. Using the old-style 'snap' switches
is OK for 12volt. The result will be that there is still lighting in case of an inverter failure and the inverter is used less. I would have to put
in another load center but these are cheap - $30 or so will do it (SquareD says there single pole 15 amp breakers will work).
Given a 3 room, 900sqft, occasional use cabin, what would you do?Diver - 6-3-2011 at 08:55 AM
Using 12V for anything you can will conserve power.
Converting from 12V to 120 ... you lose some.
We have a 2-panel system and I still use a 12V water pump, lights, fans ... outlets are for TV, microwave, curling iron and hot waxer ... bkbend - 6-3-2011 at 10:04 AM
I'm only slightly less new at this than you, so I can't give expert advice. I was going to go entirely 120v but since most of the lights already in
place were 12v I've decided to keep those and add a couple others as 12v to reduce the inverter overhead loss. The kitchen and bath are close to the
batteries so they are short runs without spending a lot on fat wire. I'll probably go with 120v table lamps for locations at the far corners.
[Edited on 6-3-2011 by estebanis]oladulce - 6-3-2011 at 03:54 PM
The LED bulbs for average interior fixtures (like regular A19 Edison base bulbs and Halogen-style MR16, PAR30's etc) are not that much different in
their power usage between 12v and 120v.
LED bulb examples:
-I found a 12 volt LED, old-fashion style Edison base bulb, that's 600 lumens (55-60 watt equivalent in light output) that uses 5.8
watts and costs $50.
-The same bulb in 120v gives off 600 lumens also, uses 7 watts, and costs $40.
-The Home Depot Ecosmart 120v LED bulb gives off only 429 lumens (40watt bulb amount) and uses 8.6 watts of power
at $18 per bulb.
-A 120v LED 60watt-equivalent PAR30 reflector type bulb uses 9 watts and costs $50 for a high quality bulb.
-For only 3 watts more you can use a 12 watt compact fluorescent and spend $4 on the bulb.
I recently finished our casa lighting plan and have collected hours and hours of notes comparing 120v vs 12v fixtures and LED bulb price comparisons
vs light output. Here's what we decided to do: The only 12v lights we'll have indoors are some eclipse step lights in the stairwell as "low lights".
The majority of our lighting are 120v 3" & 4" recessed cans and I'm hoping the cost of the dimmable LED PAR30 and MR10 bulbs will decrease by the
time our construction is done.
In rooms like a pantry, closets, utility room etc where the light isn't on for very long, we'll use compact florescent 120v bulbs- the bulbs are
cheaper, the light fixtures are cheaper and there's a much greater selection of fixtures available.
Bigwooo says we have #10 wire running for those few 12v interior lights, all of our 12v outdoor lighting, a couple of small fans, and a few outlets.
Sheeze that wire is expensive!
Here's a recent pic- There's an awful lot of the orange hose going in so I may have overcompensated on the lighting.
Bob and Susan - 6-3-2011 at 05:35 PM
after 4 years of continues use my led's are starting to burn out
very expensive to replace
the compact flouresent are cheaper
but double the wattage
luckly there's not too much differance between 4 watts and 8 watts
i go 120v all the way
just try to buy a 12v bulb
my 2 pesos
CasaManzana - 6-3-2011 at 05:54 PM
Yep...ya never find 12v bulbs down here but at West Marine boat supply they come in just about anyway you want. 12v bulbs with the standard screw-in
base allows you to use any regular light base and fixture. Each year when we spend 3 months on the mainland, we leave several on 24/7. We always get
collectively 6 months of continuous burning from these, I think because there is almost no heat produced.smlslikfish - 6-3-2011 at 07:01 PM
We have several propane lights at our place and they do work very well, however in the warmer months the heat they produce can be unwelcome, on the
other hand in the winter.............larryC - 6-3-2011 at 07:07 PM
Actually I think it is just personal preference whether or not to use 12v. The only 12v I have is the Shurflo water pump and the VHF radio. If I would
have found the pump in a 120v version I would have bought it. I know they exist. Certainly, if you have doubts about your inverters reliability (so
many are made in China) then by all means wire in some 12v. I tend to stay away from that type of inverter. You can't go wrong by adding a few
redundant light fixtures.
LarrySantiago - 6-3-2011 at 09:11 PM
Here's my solution: I all ready have two 12v fluorescent from my old Harbor Fright 45 watt system. I will put one of those in the kitchen and one in
the utility room so that if the inverter goes at least I can have light to see why and get a round the cabin from the kitchen light.
Oladulce: good info - keep that stuff coming. Interesting to us nutz-n-bolts folks. Also, out of curiosity, you use different numbers of "o" when
you spell "Bigwoo". Sometimes it's "Bigwoo", sometimes it's "Bigwooo" and even sometimes "Bigwoooo". Is there some meaning that I'm missing?monoloco - 6-3-2011 at 09:42 PM
Go 120v and buy high quality LED's, you won't be disappointed. The Eco smart bulbs have a 5 year warranty and the Phillips have a 6 year warranty,
Cree is also very good, the light quality is way better than fluorescent.oladulce - 6-3-2011 at 11:26 PM
Quote:
Originally posted by Santiago
Also, out of curiosity, you use different numbers of "o" when you spell "Bigwoo". Sometimes it's "Bigwoo", sometimes it's "Bigwooo" and even
sometimes "Bigwoooo". Is there some meaning that I'm missing?
Depends on the weather and our percentage of charge. Nice and sunny, with batteries topped off at 100%, I have permission to add the "oooo's" with
reckless abandon Bob and Susan - 6-4-2011 at 05:18 AM
damn oladulce you're smart...
also LED's sometimes flicker with inverters and generators
annoyingmonoloco - 6-4-2011 at 05:43 AM
I have a whole house full of LED's running off the inverter and none of them flicker.
