Inverter installation and automatic transfer switch

[DOITHARD]

Need help!

2016 Lance 1172

I'm in the planning stages of purchasing and figuring out installation of a 2500 watts inverter.

I would like to install inverter 120v to camper 120v panel. However, camper has an existing automatic transfer switch...can the inverter be connect to the ATS and if yes, which feed shore or generator?

PS/ I realize that I'm restricted on amperage...I will only be using 120v for TVs, Directv receivers or charging phones and lap tops. Maybe once in a while a coffeemaker or MW.

Thank you in advance!

Carlos

[mapguy]

DOITHARD wrote:
Ok so I will run MW with Genset...I'm planning on purchasing a PSW inverter and will install an add ATS. But where do I conect the ATS to, shore power at existing ATS?

Depends -whole panel or just inverter driven circuit/outlets. Easiest/seamless usage would be circuits/outlets. Check the link and investigate the pdf documents.
ST1500 psw at Best Converter

Search member smkettner posts for more install info, too. There are some smart guys here, too that will help if you outline your needs clearly and are reasonable. In your original "needs" the microwave just wasn't feasible.

[DOITHARD]

Ok so I will run MW with Genset...I'm planning on purchasing a PSW inverter and will install an add ATS. But where do I conect the ATS to, shore power at existing ATS?

[mapguy]

Would agree existing battery capacity is at best marginal for running 2k watt inverter for more than a minute or two. A true sine wave inverter with transfer switch seems to be the ticket for painless usage.Wire it inline for desired circuits as already suggested by some people that are smarter than me. Something like a Samlex ST series unit would be a candidate for me as outlined.

[SoundGuy]

DrewE wrote:
It makes very little sense to get a 3000 watt inverter if you'll only have two batteries. It's somewhat akin to attempting to tow a massive 5th wheel with a F-150.

Nor (as I mentioned earlier) does it make sense to expect to run a microwave oven with just 2 batteries as source power ... sure, it might initially work when the batteries are at full charge but as they draw down chances are voltage drop will be so severe with such a heavy load on just two batteries that the inverter's low voltage alarm will trigger and eventually the inverter will shut down. The solution is to increase battery capacity to at least four OR better still eliminate the one and only heavy draw item in the OP's original list of items he wanted to power (the microwave) and there's no reason he can't do any one of them with a 1000 watt PSW inverter.

[DrewE]

It makes very little sense to get a 3000 watt inverter if you'll only have two batteries. It's somewhat akin to attempting to tow a massive 5th wheel with a F-150.

If you want to energize the whole electrical system with the inverter, you need some sort of a transfer switching arrangement that will not allow it to be possible to connect it simultaneously with the shore power or with the generator power. (In saying earlier you could use the existing transfer switch I assumed you did not already have a generator connected to it. That was a bad assumption. It's not possible to connect three sources to the two inputs of a single two-way transfer switch.) A parallel connection with manual disconnects is not a safe or appropriate option; anything that relies only on one's memory, rather than some sort of physical interlock, to prevent connecting two sources simultaneously is unacceptable and contrary to electrical codes.

Perhaps the simplest/lowest const way is to connect the inverter output to a socket you can plug the shore power cord into. If the power cord is permanently attached to the RV, you might be able to put this socket in the compartment where it's stored and simply plug it in whenever you stow the cord when breaking camp.

An automatic (or manual) transfer switch also works fine. It's obviously more costly than a simple socket, but may be more convenient. The transfer switch will generally have to switch both the hot and the neutral lines, both hot lines and the neutral if you have a 50A RV. You typically cannot use a transfer switch intended for a residential emergency generator that only switches the hot lines.

[DOITHARD]

Ok, so found an AIMS 3000 watts PSW inverter w/ transfer $600.00 +/- not sure I want to spend that much.

In lieu of not installing an additional transfer switch and keeping it somewhat simple. What about connecting the inverter to the existing ATS shore power and installing a disconnect switch prior to ATS? So, if Im not using inverter its totally off from electrical system and avoid any damages in the event shore power or generator is energized.

[DOITHARD]

KD4UPL wrote:
I think you must already have a generator in the camper?
You want to use the one existing transfer switch to select between shore, gen, and inverter? That can't be done. You would need an additional transfer switch.
You could use an inverter/charger with a built in transfer switch. You would connect your shore cord to it's input and it's output to where the shore cord is connected now. This would eliminate the need to turn your converter off when on the inverter (you would just permanently disconnect the factory converter).

I think you have the right idea...now let me do the research for a PSW inverter/charger, maybe the cost will be prohibited and would have to resort to wiring a couple of outlets independently to the inverter.

Btw, I do have a propane generator in the camper...just hate with a passion the racket.
Thank you all for the help!

[KD4UPL]

I think you must already have a generator in the camper?
You want to use the one existing transfer switch to select between shore, gen, and inverter? That can't be done. You would need an additional transfer switch.
You could use an inverter/charger with a built in transfer switch. You would connect your shore cord to it's input and it's output to where the shore cord is connected now. This would eliminate the need to turn your converter off when on the inverter (you would just permanently disconnect the factory converter).

[SoundGuy]

DOITHARD wrote:
The rationale behind the high inverter wattage is just in the event I want to run the microwave or coffeemaker. I have (2) group 31 AGM 200ah each w/ 430 watts solar panels and 40 amp MPTT controller.

Coffeemaker sure, but those two G31s will struggle if you attempt to power a microwave oven ... for that you'd want double that capacity. Solar doesn't have anything to do with this aspect as it's sole purpose is to re-charge depleted batteries, not power anything directly.

FWIW, I've done the "whole house" powering scheme with my own inverter and concluded it was such a PITA that I'd rather have a few duplex receptacles conveniently located in the camper that are wired directly from the inverter - no transfer switch, no going outside to plug the trailer's main service cable into the inverter, no remembering to turn the converter off, no remembering to force the fridge to gas, no remembering to make sure the water heater's electric element is turned off.

As for the size of inverter my bet you have an MSW inverter that with a sufficiently sized battery bank would power many of the devices you intend but for many others is WAY overkill, the disadvantage being it's MSW waveform. I instead chose a 1000 watt PSW inverter which is capable of safely powering any devices we want - coffee maker, toaster, wife's hair dryer on low, fans, etc. Last season I used our existing G27 as source supply and while when fully charged it did power the aforementioned devices without triggering it's low voltage alarm this season I plan to more than double my battery capacity by replacing it with a pair of G31s ... but no way would I expect to power a microwave without a much higher rated inverter AND at least a bank of four 12 volt G31s or four 6 volt GC-2s.

[KRumm]

DOITHARD wrote:

MrWizard wrote:
any reason
NOT to put a RV female plug attached to the inverter
and simply plug the shore power cord into the inverter
lots of people have done it this way
saves a whole lot of wiring hassles

you still have to make sure the converter is turned off and WH and fridge are on Manual LP, NOT auto mode

I'm lazy and don't feel like dealing with cords...lol

You can hardwire the cord in... As stated this is the least hassle method... View the install here:

https://www.youtube.com/watch?v=gm4NeZCQyvY

[KRumm]

You might check this out - It has a built in transfer switch and charger built in...

In your situation you could install it between your present transfer switch and the 120v panel... and remove/disable present charger

http://www.xantrex.com/power-products/inverter-chargers/freedom-hfs.aspx

https://www.youtube.com/watch?v=MtQQupeOF60

[time2roll]

Transfer switch wiring is the easy part if you power the entire panel.
As said above you just need to make sure certain items are set to propane or stay off.

Transfer switch has two input and one output.
Cut the existing feed and connect to the input and output. Inverter connects to the second input.

If you want to power a sub-panel so only "inverter" items are powered up it just adds a bit of hardware. Or you can power individual circuits after the panel. Whatever works best for your camping style.

[DOITHARD]

MrWizard wrote:
any reason
NOT to put a RV female plug attached to the inverter
and simply plug the shore power cord into the inverter
lots of people have done it this way
saves a whole lot of wiring hassles

you still have to make sure the converter is turned off and WH and fridge are on Manual LP, NOT auto mode

I'm lazy and don't feel like dealing with cords...lol

[DOITHARD]

I'm trying very hard not to run the generator unless the temps outside are unbearable.

[DOITHARD]

smkettner wrote:
2000w is plenty. 300w is plenty for tv, direct, phone, laptops, dvd.
Sine wave is best with MW and CM electronic controls.
Best to have 4+ batteries to drive 2000w.
Transfer switch can be installed in sequence with existing.
Don't forget the LED lights and 200+ watts solar 😉

I don't mind spending the money or doing the wiring...your idea of an ATS is interesting but don't understand how to wire it! The rationale behind the high inverter wattage is just in the event I want to run the microwave or coffeemaker. I have (2) group 31 AGM 200ah each w/ 430 watts solar panels and 40 amp MPTT controller.