12v/120v System From Scratch

[bredlo]

Hi fellow 'streamers,

We've passed some exciting milestones so far in our reno: new axle, holding tanks, floor. Fantastic fans are in, windows have been painstakingly restored and rivet stems are filling the driveway. Most appliances have been purchased, and two shiny layers of Prodex are ready to install into a clean, empty shell.

By week's end, we hope to have traced down all leaks, installed the first layer of insulation, and leap into the next phase: electrical.

I have almost no hands-on experience, have limited understanding, and don't own or know how to use a multi-meter. I've read many threads and am not afraid of research. I'd probably like to hire an electrician (or boat / trailer expert) in the NE Illinois / SE Wisconsin area to let me "shadow" them on this... but meanwhile I'm always appreciative for any advice or links to I can at least collect the right supplies.

1. I'd like a simple, elegant system sized for a week of boondocking, as we have at least enough water and propane capacity for that. I realize that's difficult, given how much depends whether we sip - or gulp - our electricity.
2. Love the idea of solar but currently have little interest in making the commitment.
3. I'd like to get by without a generator for the time being. If we do get one, a little Honda eu2000i would hopefully augment the system nicely.
4. Along with a converter, I'm interested in a pure sine inverter so we can charge laptops and run a few appliances when boon docking. Wondering if there are combo units...
5. Batteries: AGM, vented, sealed, 12v, two 6v golf cart batts... I don't have a preference, but will do homework rather than ask you to rehash something so easily researched.
6. Keeping within a 30AMP breaker (vs. 50) seems preferable given cheaper campground spots, if possible.
7. For the moment I want to plan for an incandescent bulb-based system vs. LED., as it seems going the other direction would be more difficult.

Here's what we're planning for.

120v:

• Air conditioner. Haven't bought one yet - likely a 6K BTU window-style unit hidden behind a cabinet: 5.2-5.6 amps
• Charging 2 laptops, 2 iPhones, iPad and camera battery (at once): maybe 8 amps
• 1000w Hairdryer: 8 amps
• Coffeemaker: 6-9 amps
• Around 10 lights, avg. 60 watt bulbs: 5 amps
• Some type of household fan: 1 amp
• Perhaps a half dozen outlets dispersed around the trailer (zero draw when not in use?)

33 - 36 amps for 120v (we obviously wouldn't run everything at once)

• 12v:
• 2 Fantastic Fans: 5.2 amps
• Shurflo pump: 7.5 amps
• Isotherm fridge/freezer: 6 amps when compressor running, 2.3 when not.
• RV-550 NSP tankless water heater: Unknown
• 8 exterior lights: clearance/brake/license/porch:11 amps?

So that's 30 amps, and because I can more easily imagine the items on this list running simultaneously, I suppose this bumps us up into 50 amp territory whether we like it or not?

Hopefully I'm not too misinformed so far. I'd like to begin running wire soon, and perhaps collect some of the fuse panel, batteries, charger, and other elements for our system. I tend to like well-designed marine industry products, i.e. Blue Sea, etc., if you like specific brands beyond what VTS offers.

Thanks in advance!

[Airrogant]

What a great project! It reads as if you're having a good time too.

A few comments for your consideration:

1. A week's worth of boondocking is going to require a multi-battery setup using some big batteries. Especially if you don't want to use a generator. It might be more cost-effective overall to buy less battery capacity and purchase a generator.

6. Another consideration is that the 50 amp connectors and pigtails seem to be much more expensive than their 30 amp counterparts.

7. Many LEDs use about 1/8th of the power of a comparable incandescent bulb. Since you want to boondock for up to a week at a time the power savings of the LEDs will be important. For what it is worth, I just converted most of my trailer's interior lighting from incandescent to LED (20 fixtures total). It really isn't difficult - only time consuming. I would venture to say that almost anyone can do it if they have the right tools. Since you are starting from scratch, it really shouldn't be any more difficult to install the LEDs than it would be to install the incandescents.

You might want to do a deeper dive into your AC requirements. I think that 5K BTU might just be like pissing into the wind?

When you have the lights wired you might consider spreading the lights out across multiple breakers. That way it will be less likely that you'll ever have all of the lights disabled at once. Also you might want to use 12 VDC lighting instead of the 120 VAC bulbs that you've specified.

Your list is missing several important electric users that you might want to add:

Furnace fan
Detectors (smoke, propane, CO)
Tank level system
Breakaway switch
External lighting count may be low. Strongly consider LEDs
Exterior 120 VAC and/or 12 VDC receptacles
Several interior 12 VDC receptacles
Radio
Range hood fan and light

I just purchased my first Blue Sea products and am impressed with the quality of their design and construction.

[bredlo]

Originally Posted by Airrogant

Your list is missing several important electric users that you might want to add:

Furnace fan
Detectors (smoke, propane, CO)
Tank level system
Breakaway switch
External lighting count may be low. Strongly consider LEDs
Exterior 120 VAC and/or 12 VDC receptacles
Several interior 12 VDC receptacles
Radio
Range hood fan and light

I did miss a few things on the list - thanks!

I'll do more homework, work on an overhead diagram and update the thread.

6K BTUs appears on most charts as sufficient for a 150-200 sq. feet, and our 22 footer is around 130. I'll look more closely at what people are putting in trailers though, as that may affect things.

Thanks for the suggestions!

[Airrogant]

AS put an 11,000 BTU AC unit into my little trailer. I've tested it with ambient temperatures up to about 85 degrees F in partial shade, and it still works well. The bigger trailers started out with one 13,500 BTU unit.

[TG Twinkie]

Look at a thread by Lucymcdog. It is an entire rewire of a small coach.

[bredlo]

Originally Posted by Airrogant

AS put an 11,000 BTU AC unit into my little trailer. I've tested it with ambient temperatures up to about 85 degrees F in partial shade, and it still works well. The bigger trailers started out with one 13,500 BTU unit.

Amazing - quite a difference, I plan on using a through-wall type sleeved window AC unit, perhaps under the dinette seat. I have no desire to go through a ton of work and find out I don't have enough "oomph" to cool the trailer, especially if the spot I build out won't hold a bigger unit. Thanks for the heads up!

[bredlo]

Thank you TG, I'll do that now.