Automatic transfer switch that you should avoid

Automatic transfer switch – The one from China…


If you are like me and is working on solar electricity you want everything and little more. In this case you want fail safe so that if your inverter stops working you want your house to be switched over to the grid again. Or why not switch to a backup inverter instead.

There is tons of ways of doing this and i started to look at automatic transfer switches. Their basic function is basically to switch over to a secondary connection when primary fails.

For instance if you have a UPS on your computer. When your grid fails it automatically switches over to the battery instead.


The switch i took a look at is this one:

Link to the device on eBay

How I would connect it up

For more in depth information i do recommend to check out the youtube video in top.

But my findings are:


  • You can feel the plastic
  • The mounting plate is not straight
  • They have used fuses instead of real contactors
  • Its connected up in such way that if you don’t have your load connected it will not transfer anything (Or if you have low load connected)
  • Its connected between 2 phases and could potentially burn the motor that is rated for 230V and not 400V.
  • If the fuses just get slightly worn they could both be engage in same time or disengaged leaving the device unpowered and also will not switch completely.
  • The manual was in some foreign Chinese language (Didnt expect anything else since i ordered it from over the sea)


  • Uhm hmm… It was cheap?


I do not recommend this device in current combination what so ever. Perhaps if you rewire the whole device it may work.


Disclaimer: I do not work with this kind of things to a trade and do therefore not know everything about it and may have done something wrong. But the device itself did not work when i connected it up as described.


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