Apologies if this is covered elsewhere...

[Peter Evans]

I have and grounded inverter and ground/neutral-bonded to and in a separate breaker then to a separate panel of breakers, 4/3 with ground between all. That is what it is and for good reasons.

From this final panel I want to go through a 200 amp Automatic Transfer Switch to the house main panel. I simply want to send the inverter power to power the main panel and when it stops sending power to the main panel and switch to the utility power. The amount of obfuscated information I have waded through to identify the switch is crazy. I would think I simply need a device that switches *all* wires from one to the other when it detects no power from the inverter side, so four wires in from the inverter, four wires in from the utility, and four wires back out to the main panel. I can't identify any reason why this cannot be done.

Simply switch from one power source to another when no voltage detected on one source.

So what is the device type name so I can go buy one? Thanks in advance.

 

[ggunn]

I have and grounded inverter and ground/neutral-bonded to and in a separate breaker then to a separate panel of breakers, 4/3 with ground between all. That is what it is and for good reasons.

From this final panel I want to go through a 200 amp Automatic Transfer Switch to the house main panel. I simply want to send the inverter power to power the main panel and when it stops sending power to the main panel and switch to the utility power. The amount of obfuscated information I have waded through to identify the switch is crazy. I would think I simply need a device that switches *all* wires from one to the other when it detects no power from the inverter side, so four wires in from the inverter, four wires in from the utility, and four wires back out to the main panel. I can't identify any reason why this cannot be done.

Simply switch from one power source to another when no voltage detected on one source.

So what is the device type name so I can go buy one? Thanks in advance.

You aren't saying that you want to power the panel exclusively from a PV inverter with no grid and no batteries, are you?

 

[Peter Evans]

I cannot see the confusion, I am powering the main panel from one source (inverter) or if that is supplying no power, from the other source (service). This is done on every single 18+ Kv solar installation. All solar via inverter or all house service line. Super simple.

 

[Peter Evans]

Current Update: I have identified a 4 pole (twelve connections), 400 volt, 250 amp ATS that is wifi controllable, manually controllable with a lever, and remotely wired controllable with a standard switch, ATS for $195 plus the cost to put it in a weather-proof box (standard exterior junction box).

The cost is $250 and two hours of simple labor @ $35/hr. so $350 maximum all in. Four-poles so unless I am missing something I can simply connect L-L-N-and-ground from each of the two power sources and output the four poles to the main service breaker panel and Bobs your uncle. Ridiculously overpriced for something so simple but will get the job done. I cannot imagine why the electrician quoted "thousands" unless he is getting $800 per hour to use two screwdrivers and wire-cutters/strippers.

Someone tell me where I am going wrong with my reasoning.

 

[LarryFine]

Is it as simple as connecting the inverter to the utility terminals and the utility to the generator terminals?

There will be no generator to start, so will the transfer switch still respond as you want it to?

 

[LarryFine]

I have identified a 4 pole (twelve connections), 400 volt, 250 amp ATS that is wifi controllable, manually controllable with a lever, and remotely wired controllable with a standard switch, ATS for $195 plus the cost to put it in a weather-proof box (standard exterior junction box).

Where, please???????

 

[Peter Evans]

No idea what the rules are on this site of rules and I am not going to break them, but if you copy and paste what I wrote into google it will pop up at the most popular site for purchasing things on the internet. I have no idea why the electrical supply companies and the generator companies pay thousands of dollars to build and sell an ATS just to sell what is essentially 4 double pole circuit breakers that cost $3.23 cents each to manufacture and a $2.44 circuit board that detects line voltage to determine when to switch the breakers in a $4.50 steel box and a dollars worth of marketing.

 

[Peter Evans]

Is it as simple as connecting the inverter to the utility terminals and the utility to the generator terminals?

There will be no generator to start, so will the transfer switch still respond as you want it to?

It is an ATS. All of these detect voltage on one circuit and leave that circuit connected to the output. When it detects no voltage on that circuit it automatically switches to the other circuit that has voltage. I drew a diagram and attached it.

 

[CoolWill]

No idea what the rules are on this site of rules and I am not going to break them, but if you copy and paste what I wrote into google it will pop up at the most popular site for purchasing things on the internet. I have no idea why the electrical supply companies and the generator companies pay thousands of dollars to build and sell an ATS just to sell what is essentially 4 double pole circuit breakers that cost $3.23 cents each to manufacture and a $2.44 circuit board that detects line voltage to determine when to switch the breakers in a $4.50 steel box and a dollars worth of marketing.

Probably because Asco and Eaton and Siemens are tested by a real lab to actually perform to the standards they claim to meet, instead of some chintzy Chinese Amazon junk.

 

[Little Bill]

This appears to be heading to DIY, by a non electrician so we have to close this thread.

 

[ActionDave]

Having heard from the OP letting us know his management role is part of the PV industry I am re-opening this thread.

 

[ggunn]

I cannot see the confusion, I am powering the main panel from one source (inverter) or if that is supplying no power, from the other source (service). This is done on every single 18+ Kv solar installation. All solar via inverter or all house service line. Super simple.

Perhaps I am misunderstanding you, but it seems to me that you are proposing to power a home with a PV inverter with no connection to the grid when the transfer switch connects the PV to the home, and you haven't mentioned batteries. Most inverters are designed to run grid tied and cannot run without the frequency and voltage reference from the grid, i.e., off grid, unless they are coupled with a battery bank. Residential PV systems are virtually all designed to run in parallel with the grid when the grid is available. But you know all that, right? I must not be understanding you.

When you say "18+ Kv", do you mean "18+ kW"? 18kW is bigger than most residential PV systems - most that I have designed, anyway. Specifically, what inverter make and model are you proposing to use?

 

[Elect117]

1) There are power quality problems associated with a cloud when solely run on solar with nothing to offset the sudden dip in energy production. This can have a negative impact on equipment.

2) Make sure what ever you install is listed or you are going to have a miserable time with the insurance claim and inspector / utility.

3) Make sure you are consulting a licensed professional.

 

[suemarkp]

Are you switching the equipment ground? Wouldn't a 3 pole switch work just fine if you are not running 3 phase?

 

[jaggedben]

I have and grounded inverter and ground/neutral-bonded to and in a separate breaker then to a separate panel of breakers, 4/3 with ground between all. That is what it is and for good reasons.
...

I cannot see the confusion, I am powering the main panel from one source (inverter) or if that is supplying no power, from the other source (service). This is done on every single 18+ Kv solar installation. All solar via inverter or all house service line. Super simple.

Current Update: I have identified a 4 pole (twelve connections), 400 volt, 250 amp ATS that is wifi controllable, manually controllable with a lever, and remotely wired controllable with a standard switch, ATS for $195 plus the cost to put it in a weather-proof box (standard exterior junction box).

The cost is $250 and two hours of simple labor @ $35/hr. so $350 maximum all in. Four-poles so unless I am missing something I can simply connect L-L-N-and-ground from each of the two power sources and output the four poles to the main service breaker panel and Bobs your uncle. Ridiculously overpriced for something so simple but will get the job done. I cannot imagine why the electrician quoted "thousands" unless he is getting $800 per hour to use two screwdrivers and wire-cutters/strippers.

Someone tell me where I am going wrong with my reasoning.

Most solar systems are grid tied and don't have any of this stuff. Most people doing this sort of thing would use a system with a Micro-Grid Interconnection Device and not an automatic transfer switch. While one certain can do what you are describing, calling it 'super simple' suggests you're in over your head. It is not surprising you aren't finding readily available products to do something very few people would try to do.

As far as getting the right ATS, usually for a generator (which is how you're describing the role of the inverter) one would only transfer or disconnect the hots; you wouldn't switch the neutral unless you had a good reason, like a neutral-ground bond in a generator or off-grid inverter that you couldn't remove. One would never switch a ground.

What inverter are you using and what makes it grounded?

 

[jaggedben]

Having heard from the OP letting us know his management role is part of the PV industry I am re-opening this thread.

Consider me unconvinced.

 

[ggunn]

Consider me unconvinced.

Is it just me who thinks Peter Evans is saying that he wants to run a house from a "grid tied" PV inverter with no connection to the grid? Unfortunately, I have encountered PV system salesmen who are convinced that a simple grid-tied PV system will continue to provide power to the house when the grid is down. I once had one of these guys call me and ask me to call his customer and tell them that, and when I wouldn't because it isn't true, he wanted to argue with me about it.

 

[Elect117]

Is it just me who thinks Peter Evans is saying that he wants to run a house from a "grid tied" PV inverter with no connection to the grid? Unfortunately, I have encountered PV system salesmen who are convinced that a simple grid-tied PV system will continue to provide power to the house when the grid is down. I once had one of these guys call me and ask me to call his customer and tell them that, and when I wouldn't because it isn't true, he wanted to argue with me about it.

Same thing happened with me. I was called to do a job walk and the customer was talking about utility outages. I asked him why he thought this was going to change anything with outages and he said, with the guy standing right next to him, "that's what he told me".

I could honestly fill a whole forum post with crazy things solar guys say.

 

[CoolWill]

Is it just me who thinks Peter Evans is saying that he wants to run a house from a "grid tied" PV inverter with no connection to the grid? Unfortunately, I have encountered PV system salesmen who are convinced that a simple grid-tied PV system will continue to provide power to the house when the grid is down. I once had one of these guys call me and ask me to call his customer and tell them that, and when I wouldn't because it isn't true, he wanted to argue with me about it.

He said inverter, not grid-tied inverter. I would assume he means a battery inverter. The 18 K he mentions is probably a Signature Solar 18kPV inverter, which is an all-in-one inverter that can take 18 kW of solar input and has 12 kW of 120/240 VAC output.

 

[letgomywago]

He said inverter, not grid-tied inverter. I would assume he means a battery inverter. The 18 K he mentions is probably a Signature Solar 18kPV inverter, which is an all-in-one inverter that can take 18 kW of solar input and has 12 kW of 120/240 VAC output.

Then yes a generator interlock could work in that situation but there's battery equipment that does this.

To OP remember that just because a switch or a breaker is a certain cheap price remember that listing costs tens of thousands if not 100s minimum. The cost of breakers doesn't include the cost of the breaker box and the required interlock kits the breaker is the cheapest part in a set up you're describing.