Autimatic Transfer Switch?

[Almot]

Was about to order switch by TRC/Southwire, 30A, huge 14" box, $95.  Then found an old thread by Mr Wizard, he bought some Chinese motor-driven gizmo for less than half of the cost - and it was smaller too: 2P 63A.

Now I'm thinking about this switch, smaller yet, $35: https://www.ebay.com/itm/115913695641 .  Love the size 4.75" x 3" x 2".  They have a motor-driven model too, see the pictures. At this point cost is no big deal, I would've paid $95 for TRC if it were smaller.  Incidentally, TRC had died on Mr Wiz so he went shopping and came back happy.  Love the idea of motor - it breaks the contact before making another contact, connecting both lines at the same time is impossible.  Love the Ebay Mini-switch too, no moving handle outside, my only space is in the cupboard next to pots and pans. 

Any thoughts are appreciated.

PS: new forum sucks.  Links in older threads don't open.

[JimmyG_The_One]

Transfer switches are basically just 2 relays or contactors set up in a way that only one can run at a time.

Having both "lines" at the same time is impossible.

Why would you want to change it if it works? 

[Almot]

 Jimmy, I don't want to have both lines connected at the same time :-). I want ATS to connect either shore power to converter when there is a shore power (primary source), OR - when shore power is out - I want ATS to AUTOMATICALLY, without me flipping some breaker, disconnect converter and connect standby inverter (backup source) to AC panel. 

[Community Alumni]

Im' interested in how these work also, my 50amp auto change over just went this spring, well half of it went to I had to rewire it for shore power operation so that means we can't use the inverter untill I get it replaces.  a new rv one is 400 to 500 bucks so a reliable cheeper option would be great as this is the 2nd one in 8 years to die.  the first one I think was because they tried to cheat me and only put a 30amp changeover in. 

[ewarnerusa]

WFCO makes a 50A transfer switch as well.  I have no firsthand experience with it, just the 30A one I've been discussing here.

https://www.amazon.com/WFCO-T57-Amp-Transfer-Switch/dp/B009LFZZFK

[StirCrazy]

ya a bunch of companies make generic ATS, go power, progresive dynamics, WFCO and so on.  the bad thing about this advertisment link is they don't how any pictures of the inside, but thanks for this link as it shows the inside and now I can look how they butchered my wires when they installed the go power one and see if I can make this one work.  It always amazes me at the low quality work that is kicked out of repair shops and dealerships by rv tecks and we are all ok with it.  in this case they installed the ATS and didn't leave and extra inch of wire, dosn't make sence in somthing that can vibrate down the road.  

[ewarnerusa]

My WFCO transfer switch works great.  I think it was $75, although looks like $85 now on Amazon.  Mounts right to the back of the WFCO power center out of site.  I use it to switch between inverter and shore power input.

https://www.amazon.com/WFCO-T30-Amp-Transfer-Switch/dp/B008OJ7EIA

[Almot]

Thanks.  Attaching it to my WFCO 30 - if it fits - seems perfect.  I'm only confused with the wiring. 

According to the reviews it won't work with inverter as is.  Users recommend -  quote: (to disconnect your CONVERTER input power from the circuit breaker and re-route it to the SHORE POWER input on the switch with a 15 AMP fuse so that it cuts the power to the CONVERTER when the INVERTER is switched on) - unquote.

A switch with 15A fuse, where?  I'll have to open WFCO panel and look but I don't remember a dedicated converter breaker in this model, only the main A/C breaker - if this is it.  Users also complain on a dangerous delay and suggest disconnecting the delay jumper.

[ewarnerusa]

You are right, you need a way to disable the converter while you are running on inverter power. My converter was originally piggybacked in with the AC breaker for the general outlets. I took it off the piggyback and put it on a dedicated AC breaker by itself. Then I actually leave that one off by default and let my solar do all the battery maintenance. So I don't have to worry about turning the converter off. But you are right that you would need to shut the converter off when running off inverter.

I disabled the delay on mine. So the changeover is pretty much instant. And I actually swapped my inputs around because the logic was backwards in my opinion. Even though I had originally wired the shore power input to the transfer switch input labeled shore power, it would default over to inverter power when both shore power and inverter were available. So I flipped it around. No problem when both power sources are on, no back feeding happening. 

[Almot]

Alright, if it keeps progressing that fast, I'll be with Alzheimer in no time. My WF 8955 is hooked to GFI breaker, so I reroute converter wire from GFI to ATS Shore Power input. When there is no grid power, ATS will pass the inverter 120V to ATS  output.  I haven't seen this WFCO ATS  in flesh, presumably there is only one output, so I wire  this output to converter via a dedicated breaker that I would use to shut down the converter manually, every time there is a blackout? So much for "automated" transfer switch ... I'm in North Mexico now, last week there were blackouts every day, lasting from 5 minutes to 5 hours. 

I might strain my brains and cobble up some relay to cut the converter off when there is no grid power, haven't done this kind of work for ages, is there anything REALLY automated? Not for $500 of course. There must be something on Aliexpress but this place is mind boggling, could be fine or not suitable at all.

Happy Thanksgiving, everybody.

[ewarnerusa]

It seems like you've got the jist, but are thinking of adding more stuff that isn't needed.  See if this makes sense based on what you said:

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@Almot wrote:

Alright, if it keeps progressing that fast, I'll be with Alzheimer in no time. My WF 8955 is hooked to GFI breaker, so I reroute converter wire from GFI to ATS Shore Power input. When there is no grid power, ATS will pass the inverter 120V to ATS  output. Yes, this is correct, assuming your inverter is turned on.  This will provide power to converter when there is shore/grid power available.  When there is not shore power, the converter will remain off.  When your inverter is on, it will pass 120V to AC panel as you've described.  But you have removed the converter from the AC panel as described in 2nd sentence so no power to converter in this scenario.

I haven't seen this WFCO ATS  in flesh, presumably there is only one output, so I wire  this output to converter via a dedicated breaker that I would use to shut down the converter manually, every time there is a blackout? So much for "automated" transfer switch ... I'm in North Mexico now, last week there were blackouts every day, lasting from 5 minutes to 5 hours. No, output of ATS is wired to the main AC panel supply in place of where shore power used to connect.  No need to interact with your converter at all, you've already managed that as described in second sentence of first paragraph.

I might strain my brains and cobble up some relay to cut the converter off when there is no grid power, haven't done this kind of work for ages, is there anything REALLY automated? Not for $500 of course. There must be something on Aliexpress but this place is mind boggling, could be fine or not suitable at all.  No need for this.  First paragraph solves it all.  Although I did find the logic backwards for what WFCO ATS prioritized for default power source.  I'm not sure if my unit in particular was backwards or if it was WFCO's intent, but it would prioritize the alt power source (inverter in my case) over shore power if both were available.  So I switched  my inputs around and now shore power is prioritized over alt power source.  If you find yourself also having to do this, don't forget to also transfer the converter power feed to the line fed from shore power.  Also disable the delay by flipping the switch inside the metal box.

Happy Thanksgiving, everybody.

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[ewarnerusa]

No you don't need any extra stuff. This converter wiring setup that you've discussed actually removes it from your AC panel, bypasses the ats, and ties it directly to the shore power input. If the input feed to the converter is tied to your shore power input, it will get power if there's power coming from shore. If there is no power from shore, or power is coming from the inverter instead, then converter won't have power.

I didn't mean to confuse things with the way I did it, it is what I did long before I ever installed the ats. I would just manually plug my shore power cord into the inverter output and leave my converter shut off via the AC breaker. This is different than the strategy you first mention and that the other poster said they do as well.

The ATS has two inputs, one from shore power and one from your other source which would be generator or inverter. It has one output which feeds your AC panel. The ATS transfers power from one of either of the inputs to your AC panel.

[Almot]

 If I disconnect AC feed to converter and wire it to ATS shore power input, converter will be always off, even when there is a shore power. Because I disconnected the only AC feed to converter. I want converter to charge the battery when there is a grid power because there is no guarantee that solar will always charge it. To make converter work I need to connect the ATS output to converter input. And then I will get the "inverter loop", this is why the dedicated converter breaker or some relay is needed.  Am I missing something?

[StirCrazy]

yes you are missing a lot, you need to take your power lines to your converter and put them in the same slots you put your shore power leads into.  this will make it so you only power your converter when you are plugged into a shore power source.  if you put it on the outlet of the ATS it will alway have power.  

so the way mine was set up is the wires for the AC IN and the wires to the converter were twisted togeather and inserted into the correct termals on the ATS AC in.  this automaticly means your converter loses power when you lose shore power.  I also have mine set up to prioritize shore power over solar which seams normal when using solar as aposed to prioritizing generators when using that.  

[Almot]

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@StirCrazy wrote:

so the way mine was set up is the wires for the AC IN and the wires to the converter were twisted togeather and inserted into the correct termals on the ATS AC in.  this automaticly means your converter loses power when you lose shore power.  I also have mine set up to prioritize shore power over solar which seams normal when using solar as aposed to prioritizing generators when using that.  

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This makes sense. Let's see.

Converter AC IN stays where it was - on GFI breaker in my case (or better reroute it to main AC breaker).  One more lead goes from the same AC breaker to ATS input for shore power (assuming that on this ATS are prioritized correctly - they are not, as many noted).

ATS output goes to.... where? To  the same AC breaker as suggested by Amazon users? But this is where converter AC input and ATS shore input are wired to. Wouldn't ATS respond to 120V signal on the shore power input and close the contact on this input and pass 120V of inverter to converter even though the contact on  inverter input is already closed?