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Safari Tim · 01-05-2007, 02:06 PM

I'm getting close to wiring the inverter in the Ambassador. Maybe this weekend.

I'm going to have it power two LCD tv's and a dvd player when boondocking.

My current plan is this. In the battery closet, I'm going to seperate the wiring that powers all the outlets on the curbside of the trailer and wire up a 20 amp rated plug to it.

Next I'm going to wire an AC oulet in the closet and an inverter powered outlet right next to it. So when the trailer is plugged in at a campground for example, I'll move the plug (which powers all the original curbside outlets) to the AC outlet from the breaker box. Thereby restoring AC power.

If we are not hooked to power, I'll manually move the plug over to the inverter outlet.

These outlets do not power the converter, fridge, ac, or microwave, so I don't have to worry about that. And I won't have to move the plugs around on the a/v equipment. The only problem is the AC lights are on this same circuit so we'd have to remember not to use them when on the inverter. And the bathroom outlet is on it, so we'd have to leave the hair dryer and curling iron off!

Any thoughts?

TomW · 01-05-2007, 02:25 PM

Quote:

Originally Posted by Safari Tim

...Any thoughts?

Get member Roadkingmoe to bless your final plan. He appears to be very good with inverter applications.

Tom

Jacob D. · 01-05-2007, 06:15 PM

Sounds OK to me, but depending on the size of inverter I'd be concerned about having no circuit breaker protection when running from the inverter. If it's a 200W, well, it's probably no big deal, the inverter will blow up before the wiring will melt if there's a short-circuit. If it's 2kW, I'd really want a circuit breaker in there.

A manual, hardwired transfer switch connected before the breaker box (i.e. just after the 30A service enters the trailer) would keep the circuit breaker protections and be easy to flip over. Probably $50 or less. Or you could put it where you're currently thinking of putting the plug & outlets if you're OK with bypassing the circuit breaker panel (or you could add a small breaker right after the inverter, before it's connected to the switch).

wkerfoot · 01-05-2007, 07:02 PM

Tim,

I was in a 2007 23' Safari last month and they had a factory installed inverter. The inverter was activated by a switch and ran only certain separate, marked outlets. Have you considered this? That way you would not accidently use too many appliances or forget to transfer power from the inverter back and forth to shore power.

Bill

Safari Tim · 01-05-2007, 08:02 PM

It's an 800 watt inverter and it has overload shutdown protection built in. So, I assumed I would not need a breaker on it.

Bill, that is sort of what I'm doing by isolating the inverter to one circuit instead of the whole panel.

wkerfoot · 01-05-2007, 08:24 PM

Quote:

Originally Posted by Safari Tim

It's an 800 watt inverter and it has overload shutdown protection built in. So, I assumed I would not need a breaker on it.

Bill, that is sort of what I'm doing by isolating the inverter to one circuit instead of the whole panel.

Tim,

Not the way I understood what you propose. I thought you said that the outlets would be powered be either shore power or inverter power depending on where the plug is. In my example, the inverter outlets are dead unless the inverter is on and shore power can never power those outlets.

Bill

**azflycaster** · 01-05-2007, 08:32 PM

Tim,
Have you figured out how much battery draw you are going to need to run the inverter? It takes 10 amps of battery for every amp of 120 volts you produce. The attached chart shows the battey life when running various devices.

bibbs · 01-05-2007, 08:54 PM

Tim

Use a good heavy 12 gauge cord on your transfer plug.This way you wont have a undersized link when you are hooked up to shore power and useing your high draw appliances.

Doug

Safari Tim · 01-05-2007, 09:02 PM

Here is my artistic rendering

The outlet on the right is fed by the breaker box and 15 amp breaker.

The outlet on the left is fed by the 600w inverter with built in overload and overtemp shutdown.

The wiring and plug added are rated for 20 amps.

So the idea is that I will manually plug in to which ever power source I need at the time. No electric hookups, I'll use the left outlet. When we have electrical service, I'll use the right outlet.

Safari Tim · 01-05-2007, 09:07 PM

Quote:

Tim,
Have you figured out how much battery draw you are going to need to run the inverter? It takes 10 amps of battery for every amp of 120 volts you produce. The attached chart shows the battey life when running various devices.

Well, both LCD TV's draw about 50 watts each. Have not looked at the DVD player yet. So that would probably around 15 amps

Maybe we should bring a flash light and a deck of cards instead

Quote:

Originally Posted by bibbs

Tim

Use a good heavy 12 gauge cord on your transfer plug.This way you wont have a undersized link when you are hooked up to shore power and useing your high draw appliances.

Doug

Thanks Doug. I actually picked up a 6' heavy duty 12 gauge exension cord with a right angle plug.

lewster · 01-05-2007, 09:11 PM

Tim,

Anytime you have a sharing of an electrical component in an RV, you should have a transfer switch that will eliminate ANY possibility of ever having the 2 inputs connected at the same time. From your diagram, it appears that the outlets leading from the breaker box can be powered by the inverter AND the shore power at the same time by someone other than yourself who is knowledgeable in it's design.

Every RV that has an inverter or generator that I have seen has either an automatic or manual transfer switch arrangement as a safety precaution. This can be accomplished by using a high amp double pole double throw switch. Let me know if you need more info.

Quote:

Originally Posted by Safari Tim

Here is my artistic rendering

The outlet on the right is fed by the breaker box and 15 amp breaker.

The outlet on the left is fed by the 600w inverter with built in overload and overtemp shutdown.

The wiring and plug added are rated for 20 amps.

So the idea is that I will manually plug in to which ever power source I need at the time. No electric hookups, I'll use the left outlet. When we have electrical service, I'll use the right outlet.

Safari Tim · 01-05-2007, 09:22 PM

I suppose the drawing could look that way. I drew it because that's physically how it will be.

However, the wire for the plug and curbside outlets are not connected in the breaker box.

**azflycaster** · 01-05-2007, 10:49 PM

Quote:

Originally Posted by Safari Tim

Well, both LCD TV's draw about 50 watts each. Have not looked at the DVD player yet. So that would probably around 15 amps

Maybe we should bring a flash light and a deck of cards instead

Thanks Doug. I actually picked up a 6' heavy duty 12 gauge exension cord with a right angle plug.

I hope you are kidding about the 15 amp dvd player. You listed your inverter as 600 in the drawing and that will only produce about 5 amps. I would think a DVD player would pull 1 or 2 amps max.

OK, a candle, deck of cards and a cribbage board!.

Safari Tim · 01-05-2007, 10:58 PM

Yikes!

What I meant was 15 amps DC from the battery required to run the 150watts worth of AC devices.

...back to english class for me.... good thing I bought that School House Rock DVD

Jacob D. · 01-06-2007, 03:29 AM

I think the combination of the two things you're showing in that diagram has the potential to be dangerous and I would definitely not do it that way. You're running two circuits in the same breaker box and also having one of those circuits connected to a loose plug in a cupboard.

If you made a mistake inside the breaker box and wired the "inverter outlets" circuit to the "city power" circuit you might not easily be able to detect it - after all, the outlets would still work on city power, and you'd still need to plug in the inverter when not on city power - but that loose plug you're using to change power sources would be hot when on city power. There's the obvious potential for shorts or electrocution from that, and you could also end up plugging in the inverter and outside power at the same time which would be very bad.

If you don't want to power all outlets from the inverter by wiring it in before the main breaker box, I would put in a sub-panel (you can get a very small box with just one 20A breaker) just for that circuit, and put the switching mechanism before that. But running two circuits that must remain isolated for safety inside the same box - in a way that is not at all standard - I think is a very bad idea.

If you don't have the two circuits in the same box, the plug-switching is fairly innocuous, but transfer switches are pretty cheap and foolproof once wired correctly. If you use a transfer switch for the whole 30A service, use 10-gauge wire. If you use it just for one 20A circuit, use 12-gauge.

If you get everything right, the diagram you show would probably be reasonably safe - for you. But maybe not for the next owner, or the electrician you call in 10 years from now because you've gotten old and lazy, or maybe you after you haven't used the trailer in 5 years and you forgot how it works. One of those guys - maybe you - is trying to work out why half the outlets don't work (because someone left the plug connected to the inverter), sees that one of the circuits in the breaker box isn't connected to city power and "fixes" it by connecting it... then he reaches into your switch cabinet and finds the loose - now hot! - power plug. Not a happy day.

breakaway · 01-06-2007, 07:05 AM

I agree with Lew and like the idea of a transfer switch. This one found on EBAY 130065491625 is the one I have in my home that is used with a generator.

RoadKingMoe · 01-06-2007, 08:32 AM

There's nothing wrong with implementing a "Bubba Transfer Switch" as long as you label the two boxes and plug, and implement it safely. The drawing attached gets the wire splice in the "plug wire" circuit out of the main breaker box into it's own isolated box, and provides protection for the outlets and their wiring.

Safari Tim · 01-06-2007, 10:53 AM

Thanks for the feedback everyone.

Finally Maurice helped get my implementation idea across. Thanks! Just call me Bubba...

John, I like the idea of that transfer switch on eBay. Maybe I'll research something like that as well.

BTW- just a warning. I know there are people who try to use a DPDT switch to make a manual cut-over by switching the hot and neutral. This has the opportunity to arch across the contacts, or a cheaper switch may make the one side, before breaking the other. Either case blows your inverter.

Tinsel Loaf · 01-06-2007, 07:51 PM

Use a transfer switch to avoid a learning curve with costs that will happen at some point. This is one of those things that new owners of pre owned Airstreams ask themselves, "what was the 'po' thinking when they put this thing together".