Automatic Transfer Switch

TechWriter wrote:

1L243 wrote:
I don't have an onboard Generator.

I will be transferring between shore power and the Inverter.

I assume the output of your transfer switch will go into your 30A electrical panel, right?

If so, that means when you switch over to your 2000W inverter, it will be powering ALL the circuits, including your AC & water heater.

I hope you have a large battery bank.

You assume right.

my hot water heater is propane only.

I will throw the breaker for the AC so it does not come on by accident.

Bobbo wrote:

TechWriter wrote:

1L243 wrote:
I don't have an onboard Generator.

I will be transferring between shore power and the Inverter.

I assume the output of your transfer switch will go into your 30A electrical panel, right?

If so, that means when you switch over to your 2000W inverter, it will be powering ALL the circuits, including your AC & water heater.

I hope you have a large battery bank.

He doesn't have to turn the AC on. He can set water heater (and refrigerator) to propane. He has already said he will turn off the breaker to the converter/charger. What he is doing is imminently feasible.

So OP will have to always remember to throw several switches or risk dead batteries.

Plus, if the ATS is generator preferred and the inverter is connected to the generator side of the ATS, then OP will have to remember to also turn off the inverter when shore power is applied.

Why not just use a manual transfer switch?

Or, though more expensive, it sounds eminently more practical to buy an inverter/charger with a built-in transfer switch and wire it like so (with or without a sub panel), especially is OP's wife or friend(s) will also be responsible for switch throwing:

BFL13 wrote:
"It would be difficult to run a shore cable without having to go outside."

If you can run 120 wire from the inverter to the ATS and from the ATS to the AC panel, why can't you instead just run 120 wire from the inverter to near the panel only with a receptacle on it instead of the ATS, and also since the shore power cord is on the AC panel, and you intend to run 120 wire from that panel to the ATS, then why can't you just plug the panel into that inverter receptacle, all inside the RV?

How will you run 120 wire from the Main breaker to the ATS as well as having the shore power cord on the Main breaker? However you do that, it should be the same as running 120 wire over to the inverter receptacle for manual plug in?

Sorry if I got the picture wrong, but it is interesting. Perhaps using an ATS for the inverter is something I could do too where my own set-up is kind of awkward.

It sounds like it would work but don't you think the ATS would be simpler?

StirCrazy wrote:

1L243 wrote:
My bad I missed the small paragraph in the not so comprehensive instructions that said.

"When the shore power is applied the relay is at rest and the power is to the panel.

When the Generator (Or Inverter in my case) is applied there is a 20-45 second delay and then the relay activates transferring Generator power to the panel.

If shore power returns while the Gen power is present nothing will happen. Then the Gen power is removed the relay will drop out and allow the shore power side to supply power.

Generator overrides shore power"

With this in mind and I am substituting the Inverter for the Generator The Inverter would have priority if both were connected at the same time.

Although not covered in he installation instructions I have read that when using an Inverter with the ATS the Charge Controller will need to be disconnected from the 15 amp circuit breaker in the control panel and wired directly to the ATS using a 15 amp fuse on the Panel side to prevent a feed back loop. The charger will only work when shore power has priority.

So, If I want the batteries to charge when connected to shore power the inverter must be turned off?


Typically I would just plug the shore power into the Inverter once we reached our dry camping destination.

The main reason I have decided to go with a ATS is that I want to run my refrigerator on AC when towing instead of Propane. I have towed while running the refrigerator on propane for years BUT I got the Inverter the batteries and the solar so why not run on AC? It will eliminate that, should you or should you not have refrigerator run on propane question when towing.

Any thoughts?

Ill go out and test mine, as what you want is how mine is set up, but I believe the shore power has the priority as there is no need for the inverter if you have shore power and when we are boondocking I only turn on my inverter when I am actualy using it. mine I can put the inverter switch in off/on/remote so I set it in remote and use the inside panel to turn it on or off, that way it is not consuming power when I don't need it. yes the converter is also into the transfer switch so it doesnt use battery power to try charge the batteries...

I have solar also, but would never think of running the fridge on AC while travaling as it takes a larger amount of power and that is compounded with the inefficencies of the inverter. my solar would probably make it so I was still at 100% during the trip but my thought is the fridge, stove, BBQ and furnce lasts me weeks on propane why waist battery capability on that. plus I do a lot of camping in the off season so if I was using the inverter and I am travleing during a rainy day or two I may be showing up with a lower battery capacity when I need to run the furnace and such.

so my use is I wake up hit the inverter button and turn on the coffee pot. whent he coffee is brewed I turn it off. same deal if we need the microwave for somthing, I guess I just use it so I can use some of the more convenient apliances while camping.. well some times I bring the Margaretavill camping also ;)

On a sunny day my solar can produce as much as 26 amps and I think my refrigerator only about 8/10 amps. My batteries are usually at 100% by the time I get to where I am going. If is not sunny and I am using more than I am taking in I will not run the refrigerator on AC solar.

TechWriter wrote:

Bobbo wrote:

TechWriter wrote:

1L243 wrote:
I don't have an onboard Generator.

I will be transferring between shore power and the Inverter.

I assume the output of your transfer switch will go into your 30A electrical panel, right?

If so, that means when you switch over to your 2000W inverter, it will be powering ALL the circuits, including your AC & water heater.

I hope you have a large battery bank.

He doesn't have to turn the AC on. He can set water heater (and refrigerator) to propane. He has already said he will turn off the breaker to the converter/charger. What he is doing is imminently feasible.

So OP will have to always remember to throw several switches or risk dead batteries.

Plus, if the ATS is generator preferred and the inverter is connected to the generator side of the ATS, then OP will have to remember to also turn off the inverter when shore power is applied.

Why not just use a manual transfer switch?

Or, though more expensive, it sounds eminently more practical to buy an inverter/charger with a built-in transfer switch and wire it like so (with or without a sub panel), especially is OP's wife or friend(s) will also be responsible for switch throwing:

The only breaker I will have to throw when the ATS is in inverter mode is the AC. Since I don't use AC that often and never when on batteries I will just turn it off and leave it off till I need AC.

My Converter will be wired to the panel side of the ATS so it will only charge when in shore power side and not to conflict with the Inverter side.

A combination Converter/Inverter with built in ATS would be nice but they are very expensive. I

"On a sunny day my solar can produce as much as 26 amps and I think my refrigerator only about 8/10 amps. "

My 6cu ft Norcold pulls about 350w on 120v so that is about 35 amps DC via inverter. I had lots of solar but it could not keep up with the fridge, even at high noon. Gave up on that and now leave the fridge on propane after trying that.

You would only slow down the draw on the battery by running the fridge on inverter with whatever amps solar is doing at the time. A few more amps via 7-pin would help if only they were at the same voltage as the solar, but it would still not be enough to supply the fridge's inverter draw completely.

BFL13 wrote:
"On a sunny day my solar can produce as much as 26 amps and I think my refrigerator only about 8/10 amps. "

My 6cu ft Norcold pulls about 350w on 120v so that is about 35 amps DC via inverter. I had lots of solar but it could not keep up with the fridge, even at high noon. Gave up on that and now leave the fridge on propane after trying that.

You would only slow down the draw on the battery by running the fridge on inverter with whatever amps solar is doing at the time. A few more amps via 7-pin would help if only they were at the same voltage as the solar, but it would still not be enough to supply the fridge's inverter draw completely.

I know the refrigerator uses alot of amps on startup not sure what my number is but much less once the refrigerator reaches cold. Then it depends on how much you access the fridge and maybe how hot it is outside. It could go hours before it cycles on and off while traveling.

Down the road I may add a 40 amp DC to DC charger.

Like I said I usually run the refrigerator on propane when towing if there is too much of a draw and it starts to drain down the batteries I will switch it back to propane.
It will still be nice to have energized outlets when stopping for lunch or a break without having to go outside and plug into the Inverter.

BFL13,

I went the other route.I installed an outlet hard wired to the inverter which ends at a 30 amp female plug in the "mouse hole". There are bypass plugs for those occasions when GFi plugs cause the power to disconnect, too.

That still leaves me with "extra" power from the inverter which has another inverter powered outlet in the kitchen.

1L243 wrote:

A combination Converter/Inverter with built in ATS would be nice but they are very expensive. I

Strictly speaking hybrid inverter/chargers don't have an ATS--but rather a type of autoformer. They do have "pass through" capability, if used with the inverter off.

Another possible route is to use double conversion. I often connect4ed just the converter on shore power.

I ran the RV from a 2500 watt inverter (Cobra rated to run motors) $230.00 bucks. The convertor would recharge the batteries when demand was low.

I still prefer a simple plug over an automatic transfer switch. After all--one has to turn all items off with an ATS before activating it. The difference is after unplugging from shore power, I plug into a female outlet in the "mouse hole".

I'm certain what ever method works out for you that you will enjoy it.

Prices on the inverter/chargers have dropped a fair bit. I think there are a couple that are under $1000.00.

Gdetrailer wrote:

Otherwise, if it is you simply do not like propane at all, swap the RV fridge for a home fridge conversion.. My current TT, we did a home fridge conversion, just one pair of 6V GC2 batteries powers everything we use including the fridge for 24hrs without the need for solar or a generator..

Gdetrailer,

Do you know the make and model of the fridge?