Interior lighting question

[HB of CJ]

Dallas has it right.  I should have mentioned (but didn't) that one assumes many things on this board that may not be necessarily 100% true/correct.  Dallas intrepretated my remarks literally, others may also.  Big difference between a house and a coach.  Be careful what you do---you are the one responsible for your actions.

What I meant to say is that the 12vdc chassis side will be left alone with some updates in lighting.  The coach/house/home/boat side will be wired correctly to code (better than code) with proper 115 vac wiring, fixtures, appliances, connections, grounding, bonding etc., running thru one (1) small sine wave invertor and one large sine wave invertor.

The enclosed, dedicated gen set will feed from the rear 100 ga. fuel tank and will have the necessary to-code fire proofing, insulation, exhaust, breakers, etc..  Excessive starting/surge loads will be handled by the invertor, thus reducing the necessary size of the gen set.  The primary useage of the coach will be extended dry-camp boondocking. 

[Jerry32]

I prefer DC lighting as it only requires one wire since the coach is ground everywhere. I took some of the 24 volt ballasts and put them in 120 volt flo lites and it works just fine and puts out light the same as a 40 watt tube does on 120 AC. Jerry

[Tim Strommen]

LEDs may be the way to go if you are looking for a simple/redundant system with rather high efficiency.

Five or more years ago, LEDs were only really good for calculator displays, novelty flashlights, and dashboard indicators...  Now LEDs are used in sunlight readable video displays (think "jumbo-tron"), exterior vehicle lighting (heavy trucks down to exotic sports-cars), and other previously incandescent-only lighting applications (Audi uses LEDs for Daytime running lights, and headlights in some models now - LEDs are starting to replace all traffic signals, and making inroads to street lighting).

Some luminaire (light-fixture) manufacturers are grasping the idea that the incandescent light has its days numbered in many applications, and they've started producing LED retrofits and new designs based on LED selling points (low energy consumption, high efficacy for energy consumed, directed light energy for smaller reflectors/optics, less glare, tighter controlled light color, etc...).  As an example, in a newsletter I receive from Philips-Lumileds - they have a picture comparison of a sodium based "torch" street light, versus an LED retrofitted fixture (picture attached).

The trick with LED lighting is knowing what you are looking for.  There are products on the market today which are LED based (Hockey puck type), that can be mounted below a cabinet to light a worksurface (i.e. a counter, or sink).  Powering them from 12Volts is simple - getting power to them from "shore power" can be as complicated as you want.  If I recall my commercial aircraft electrical correctly, a "ground-based" power supply plugged into the side of the fuselage on the tarmac can actually feed the existing low-voltage power bus with a DC source by having a dedicated converter (either transformer-recifier-stiffening or rectifier-switching-stiffening type supply).  This way a diode stops shore power from backfeeding into a battery system (and vise versa), or a shore powered relay isolates a bus from the battery supply when power is active and connects it to the converter's output (a neat trick if you also charge your battery from shore power, and don't want the loads to interfere with the charge current/voltage).  This way if you have a failure of a converter, you have a battery to fall back on, or if your batteries are shot you can use shore power - all without having duplicates of circuits (maintenance nightmare due to needing both 12v and 120v bulbs and fuses/breakers available), or changing the user's operation of the system.

If you want to run 24volt fixtures (if you have an all 24-volt/all-electric rig) some LED fixtures are pre-made to support voltages from 10volts to 30volts.  Even better, if you are tenacious and like working with electronics (I'm guilty of this), you can build you own fixtures the way you want them to be made.

As for redundancy, LED fixtures will typically have a bunch of LEDs, instead of one filament to blow - depending on the internal wiring, many LED fixtures allow for a "gracefull degradation" in light output.  Oh and did I mention the typical lifetime of LEDs?  50+ thousand hours... (most incandescent bulbs are rated to 5000 or less). 

I was thinking of more to say - but my mind is numb from work...

-Tim

P.S. in the picture below, the sodium fixture implementation is on the left, the LED implementation is on the right - both shots were taken in the same location for the sake of Apples-to-Apples comparison (P.P.S. - Photocredits for the photo(s) were not specified, so for the time being assume "Philips-Lumileds San Jose, CA" or "Midwest Circuits Ferndale, MI"). -T

[Dave Siegel]

I faced that very same question, about where to put 12 volt lights and where to put 110 volt lighting. Our coach is quite small in comparison to your MCI's (1948  Silversides) so I had to get creative and I took the lamp (110 volt that I wanted to use and added another small set of wires for 12 volt lighting and clipped a small socket in there. Now the same lamp does double duty depending on what I want to use.

This may not be acceptable with all of you , so my second suggestion would be to have at least one 12 volt light in every area that you may want to use. ( For boondocking) Then add your 110 volt lighting as you need. Remember, under cabinet lighting works very well, is better for people with vision problems [me] and saves a lot of space.

Just my two cents, 'cause it worked for us.

Dave Siegel  PD3751 Naples , FL

[jjrbus]

Bus is like large lamp? Maybe that is why I get so many bright ideas in here Some low voltage backup lighting is nice. Lightnng trips the circut breaker at the RV Resort and you are scrambling around looking for a flashlight.
I have 120V, 12V, and 24V in my bus. Some of the 120V halogen ligting products are actually low voltage 12/24V DC and can be used in the conversion by just eliminating the 120V transformer. Some of these are compact and ideal for a conversion.

[Dave Siegel]

I've done the same thing as jjrbus recommended. I have two strings of under cabinet "hockey puck" style lights that are 120 volts. I took the transformer out of the circuit and wired them directly to the 12 volt house lines and , viola lights. I use a decent converter and that powers my 12 volt lights when I am plugged in. Other wise they work off the house batteries. Cool.....very cool.

Dave Siegel PD3751 "Silversides" Naples, FL

[gumpy]

Mixture for me.

I have some 12v LED pucks in the shower. Will be putting these all through the coach, mostly for boondocking.

I used some halogen pucks in the water bay. Just put them in last week. If I can get a good deal on them, I'll put them in
all the bays. They're kind of expensive. Individual pucks are like $7, but a pack of 3 w/ transformer are only $19 !!??  Marketing.
Don't need the transformer. They're 12v.

I'll use some 12v RV flourescent lights in a couple places, and I will probably use some 120v compact flourescents in the bathroom
light fixture above the sink.  I also have the 120v flourescents from the parcel racks that I currently use. I may use them in the
final coach, but not sure.

And just yesterday, I was at Menards, and they had some track lighting kits on clearance. They have 2 tracks and 3 nice lights.
They are 12vac, so I can throw the transformer out and hook the light tracks directly to 12v. Original price $99, on clearance for
$39. I couldn't pass them up. Bought 4 sets. Not sure yet where they'll end up, but I suspect in the living room, and possibly
bedroom. They're halogen lights, so use considerably more power than LEDs, but still not to bad, and they'll put out quite a bit
more light than LEDs would.


craig