Automatic Transfer Switch

[1L243]

Iv'e decided to add a Automatic Transfer Switch to my Toy Hauler I installed a solar system with a 2000 watt Renogy Inverter several months ago.

I purchased a 30amp Progressive Dynamics ATS. I also recently added a Progressive Dynamics 4 way charge controller in place of the OEM charger. The ATS will switch between Shore Power and the Inverter.

Question.

If plugged into shore power and the inverter is on at the same time which will the ATS select as priority?

























Q

[BFL13]

"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.

[1L243]

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

[1L243]

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.

[1L243]

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?

[TechWriter]

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:

[1L243]

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.

[BFL13]

My manual system is based on the shore power cord from the Main breaker going to a compartment box with an outside door/cable hatch. If the trailer has the kind that you plug the shore power cord into an outside receptacle, then my system would not work--but something would.

I pulled the whole 30a shore power cord inside and have it tucked under the kitchen counter where I can get at all this via the under- counter cabinet doors. There is a portable surge guard and 30/15 adapter on the end of that-- all under the counter.

I have a long 12 gauge extension cord with a triple receptacle end on it as my outside- going shore power cord, that goes in that cable compartment behind the cable hatch same as where the OEM cord went, that can be pulled out to shore power or a portable gen.

I have an extension cord from the inverter to where the outside new shore cable comes in. I have a converter that has a plug-in cord that is also extended to that spot under the counter.

The trick is, I also have a short 12 gauge cord with a receptacle on it, which is plugged into the long one's triple AND so is the converter's cord. (using two of the three )

So--the OEM shore power cord inside can be plugged into Either the short cord leading to the outside cord OR into the inverter's cord.

The converter only works if the long outside cord is plugged into shore power or generator. I can run the converter off the gen or shore power and have the rig run off the inverter if that is the scenario where the batts keep getting charged as the inverter does heavy loads from time to time that might pop the outside shore power if using that directly (PT's trick for when on 15a shore power)

[pianotuna]

My RV since 2009 has behaved as if it were always on shore power. I first used double conversion, but changed to a hybrid inverter/charger of 3000 watts. I'm told there is a type of autoformer in the inverter/charger.

This eliminates the need of a transfer switch.

[StirCrazy]

StirCrazy wrote:
I don't understand why you would want your generator to take over from your shore power,

Bobbo wrote:
So you can exercise your generator under load without having to go out and unplug from the pedestal. A bad idea, but it is done.

thank you, thats all you needed to say and it makes sence.

now here is the deeper question. of you look at any system that has both the genny and a inverter it uses a two ATS set up, or there may be a fancy three input one but I would imaging that would be very expansive. so going by the two system setup. the first is for genny or shorpower and like you said the genny would have priority but when you use the second ATS the priority in to that is the output of the first, so the inverter never has priority for a simple reason, if you are plugged in you want your batteries to not be used so they remain charged. the only time you would actualy use the inverter is if you have a power issue when plugged in or you are boon docking.

so here is a description of mine from the manufacture

"50 amp transfer switch provides
automatic power switching between two separate
120/240 volt AC input sources. It automatically
connects shore power (when available) to your
breaker panel.
When unplugged from power, it then connects your
inverter output to power your circuits. The TS-50 is
a double pole switch for 50 amp services with two
separate 120 VAC legs"

so from that I read the shorpower has the priority which is how a inverter set up should be done.

Steve

[StirCrazy]

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 😉

[Bobbo]

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.

[BFL13]

"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.

[TechWriter]

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.

[1L243]

I don't have an onboard Generator.

I will be transferring between shore power and the Inverter.

I will also disconnect the Converter/Charger from the 15 amp breaker on the panel to the panel side of the ATS.

As far as the instructions go I will be substituting the Inverter for the Generator.

It would be difficult to run a shore cable without having to go outside.

[3_tons]

So sounds like you already have a generator, and if so then we should presume that you also already have an ATS switch built into the system…

So you question seems centered around adding another ATS switch at the inverter’s output…

This is very common, but the problem is that your OEM Converter-Charger will then become operable (via inverter) and attempt to charge the batteries while the inverter is on - a ‘round robin affair’…

So the solution is:

a) at the existing OEM ATS, add a ‘parallel line’ at it’s 120v output (which normally supplies the main panel ONLY) to go to the newly installed ATS input, and the inverter output to the generator side of the new ATS…In this way, power will cascade properly (no sinusoidal conflict - shore power the priority) whether inverter is On or OFF…IF no shore or genny power is present, the inverter (IF in standby…) will kindly take over the load without interruption…Note, the PD’s time delay can be defeated (see manual)…

b) dedicate the new ATS switch output to drive a small sub-panel…Relocate any circuits (and breakers) that you wish to power-up via the inverter (say like, microwave, refer, household receptacles, etc) from the main to the new sub-panel….New sub will then receive power from either of the aforementioned sources (see item ‘a’), but the key here is that ‘inverter power’ cannot flow backwards (say to supply the Main panel, or converter-charger)…In this way, shore power (or generator) will power-up simultaneously both the main and the sub, but the inverter will only supply circuits relocated to the sub…

3 tons (Feel free to PM me…)