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Almot's avatar
Almot
Explorer III
Nov 22, 2023
Solved

Autimatic Transfer Switch?

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.

  • 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's avatar
      Almot
      Explorer III

       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's avatar
    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. 

      • StirCrazy's avatar
        StirCrazy
        Moderator

        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.  

    • Almot's avatar
      Almot
      Explorer III

      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.

      • 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. 

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