Transfer switches

Anyone have any experience with these? GEYA Automatic Transfer Switch Grid to Alternator 3P 100A 230V Dual Power | eBay

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Looks like a newer vendor, the price is right and ratings mostly positive. Other than that, it looks like it would work… I am going to look more at the specs. :sunglasses::cowboy_hat_face:
They have a 2 pole version on their EBAY store site.

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I see some curious things.

First thing this is a 240 volt unit made for something other than a North American Edison 3 wire system.
This is important, some places, like Ontario require you to also separate your systems common from the utility to avoid any situation where you may back feed power to Utility mains.

There are different version of this but I can’t sense of them without some research to understand how they should be wired.

NUMBER ONE ISSUE ( I am typing very loud for a reason )
I see no CSA, No UL, CE or any other marks of acceptance that I recognize.

GB/T 14048.11-2016: is a Chinese standard.
What ever that is…

I would be a little worried using this ( to put it mildly )
It might be a good product, but if there is a ever a fire your insurance will not cover you.
Depending on where you live you might get a field evaluation done by a local PU inspector ( or arms reach organization like ESA ).
They may decide its good and let you use it.
However does your insurance have a clause in that they only except CSA us/can OR UL certified equipment in your home?

Here is an example this unit clearly indicates it was manufactured to meet North American standards ( I picked this Asco because its the first thing I saw on ebay that I know )
It says CSA right in the centre so you not guessing.

The seller in that auction also wants 700 USD for it, so you get what you pay for or you pay what its worth to you.


I guess my first question is why do you want an automatic transfer switch? If you are doing anything grid attached the best bet would be an old school manual knife switch box. Otherwise you have to make sure the unit is certified in the USA to prevent back powering the lines. That is no small issue because if lineman get hurt the power company comes looking for anyone who might have accidentally back powered the lines. There is an old manual AB switch here for our generator backup of the milk room. To my way of thinking if you are attached to the grid either go old school manual or modern hybrid inverters that are designed to support island mode operation.


This should not be used for grid tie. That being said, this is a transfer switch. It should be mechanically impossible to back-feed the grid if it is properly wired. You are either powering your destination circuit from the breaker box, or from your generator. there should be no path from the generator directly to the grid, even if the logic screws up. As always, buyer beware, and if you don’t know what you are doing, this is not the product for you. Hire an electrician.


I am inclined to build things, because I am an electrician but that does not mean I am right and they way they continue to regulate and tie my arms behind my back I should not give advice or suggest things build of even modify things anymore.

But one I could once…
I could modify and rebuild things even build my own and get a simply field inspection and that would likely be all I needed.
I was deemed " qualified "

That all said.
To build an automatic transfer switch you need to start with something that is rated to carry the loads and flip between utility and external source.
These little AB contactors would do nicely…

This is a bit overkill but next you want some controls to sense that Utility mains have gone down and get your back ups running and connected as well as monitoring the system and returning you to utility AND shutting your emergency systems down.
Plus its got buttons and lights and screan to tell you things…people like that…

Again I would be inclined to build my own, run it by the ESA guys and see if they except it…

This is a simple triple pole double throw switch with all the right ratings that you local inspector might find completely except able.
But you have to be there to throw it


I am looking to switch from solar to grid when solar is low. I have two main panels one is grid one is solar. This is a new system that I can pull circuits from grid panel to solar as I add hydro, or more solar. Manual would be fine if you can stand by the panels and switch it 24/7.:smirk:

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yup, as mentioned above: not with a 10 ft pole… What is it for Al? I have an auto transfer switch built into my inverter and a manual generator backup panel which also disconnects the neutral as required here in Ontario. So I can choose grid, inverter with grid passthrough or off grid. Works well for uninterrupted power…
Cheers, David


This is a perfectly good and simple to wire unit that would let you selectively switch loads.

And here is some other stuff I just wanted to post, but again I should not give advice on this, you need to research and follow your local codes if you build yourself.
You shoudl still understand the components and your options if you pay someone to do it so you get what you really want and need…

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You will need more than just a transfer switch you need a inverter and storage to make solar power AC loads. Like David said this is all built into the modern hybrid inverters.


Yes I know that, I have everything I need, I have been doing this for 40 years. I did 480 3 phase work .


No insult intended. My point was simply that a grid attached system doesn’t switch back and forth every time a cloud goes over head. The system either has storage and only depends on the grid when the storage is empty or without storage the system is running a grid attached inverter which will handle the feedback issues without the need for a transfer switch. So your comment that you didn’t want to stand there all day with a manual switch doesn’t make sence to me.


One of my chums at work does Solar installs and sells both kind of inverter systems.
Some folks use net metering to offset the additional costs of battery systems.

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Yep, too much red tape here, already checked.

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When the r3d tape here started to get too deep I had a very clever thought…
I can not do stuff to my house but they can not stop me from making stuff I can unplug.

To that end I thought a lot about a solar wind system that was grid connected through and MG set plugged into the wall.


Hi Al, I did not mean any insult I was just trying to figure out your end goals. I would say if you don’t want to feed back to the grid due to red tape then a straight off grid with grid support would be the way to go. There are a lot of flavours there. I use a Magnum MS4024 inverter with the basic remote and use a simple timer to turn on the grid late at night. I have the “absorb” time set to one minute that way I know I’m not using the grid to do the less efficient top up charging on my batteries. It feeds into a generator backup panel which is forever set at “generator”. Pretty bomb proof and simple. Next I could upgrade my remote to the ARC which allows grid use based on battery voltage; more hands off and a simple retrofit. Next comes the inverters with “Grid Zero” features that were specifically designed for cases like yours. The Outback Radian and the Schneider equivalent are the leaders there. The grid is always present and you can program it with near infinite variables as to when the grid takes over or assists all without any power flowing back or no utility permissions required.
Cheers, David


In the past 25 years I have watched the power systems get super sized.

Where a nice easy 500 kVA transformer used to be plenty they decided to move to 750 1000 and I even see a few 1333 ( where that number come from ? )

Where a 500 was too small we used to build electrical vaults with an A side and B side and use two 500…

So where am I gong with this???
The bigger the transformers, the larger the larger the cables the more available energy to to cause really destructive faults.
At the same time I notice breakers that used to be just fine at clearing a short circuit and preventing accidents and fires these are now failing and causing the accidents and fires.

New standards are introduced with stronger breakers, better fusing and more robust enclosers.
But I think we tottaly missed the point.
We should have kept things small to reduce the available fault currents in the first place.
Did you know that a lot of the IEC stuff made in the EU countries can’t deal with the faults our stuff here is designed for?
They have better standards and actively design to keep these currents down.
We just super size …

So when you buy something made in another country you had better question before hand, can this deal with a North American power system wide tolerances and very big transformers and cables designed to be cheap and efficient ( but generate Hellish fault currents )

I get asked to do things sometimes ( soapbox time )
They say "Wally old man " go and put this lexan window in that S&C switch… replace the broken safety glass…

Safety glass? Lexan?
Are you sure plastic will not liquefy and blow out under a major fault.
What if that switch fails you do not need PPE to switch because its metal clad but is it still going to do its job if I use Plexiglas glass?
Now I am the stupid trouble maker for refusing to do this without explicit proof from S&C this is OK to do?
How many other people just randomly do that?
How many people are just doing what they are told around here and random substituting parts from the cheapest supplier ( our global procurement program to save money )

I have one foot stuck in the past, I do not like to wear the heavy suit so I don’t but I get mad about using parts that would require me to where a flash suit because the super sized power system and dubious parts. ( I never need this before… )
And I have that other foot firmly planted in the the reality of today where you can’t trust things to work right anymore and you need to be afraid they will blow up and set you on fire.

So keep this ramble in the back of your mind.
The NFPA in the USA set the standards for electrical equipment not to set you or your stuff on fire.
But today’s stuff is even better at setting things on fire than ever and tha only thing between an accident and normal function of safety and protective devices is the promise from UL and CSA that they tested that electrical apparatus under the worst conceivable conditions of use today and it passed and meets the current standards.

Don’t buy cheap Ebay stuff.
Nuff Said…


Please look at my original post. I just ask the question if anyone knew any thing about those switches, or any like it. I did not buy it, just had never seen a compact self contained transfer like those, it really fits what I need. Sorry I got a little testy. I did not intend on a long drawn out thread about electrical safety. The plant I retired from I had to 40cal. suit up just to turn mains off, and on in our switch gear room. Now all this said I still need a transfer switch. :sweat:


You sir have made an excellent point.
I am off in the weeds rambling and smarting from lost battles and generally upset about being ignored…
Not by you.


Exactly what I want to do with an auto switch, on an expandable system to add circuits as I see how much power I will be able to produce.