Manual transfer switch,240v

Mr and Mrs Tupcox

Mr and Mrs Tupcox

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Hi I want to connect my vans 240v system to inverter. So looking at fitting a transfer switch ,which has 240v hook up lead off site and inverter, so van will have 240v off grid.
Don't want run separate cables and sockets.
If any has done this please advise and recommend a transfer switch.
 
I recommend mine :D
What can I say - if I need one, I make my own. Never bought one.
 
I did a very BAD version, a lead with a plug on each end into a socket behind a panel in the self-build, only the inverter plug was accessible.
 
Instead of a switch that you have to remember to use/change why not use a relay? Have it wired that the "resting" contacts are wired for your inverter but when the relay "detects" mains it switches over, simples!!
 
Wildebus/Pudsey Bear are your replies in answer to my relay suggestion? Would be interested to learn why!! It was an idea I muted in my head before I managed to get all singing dancing inverter with automatic change over when it detected mains but certain I hear a relay click when it changes!!
 
Wightman said:
Wildebus/Pudsey Bear are your replies in answer to my relay suggestion? Would be interested to learn why!! It was an idea I muted in my head before I managed to get all singing dancing inverter with automatic change over when it detected mains but certain I hear a relay click when it changes!!
Click to expand...
Not exactly, just what I did short term as I only needed this function to charge tools while I was building the van, and didn't want t run a lead from the garage, it got removed once it was finished
 
Wightman said:
Wildebus/Pudsey Bear are your replies in answer to my relay suggestion? Would be interested to learn why!! It was an idea I muted in my head before I managed to get all singing dancing inverter with automatic change over when it detected mains but certain I hear a relay click when it changes!!
Click to expand...
My reply is specifically to Pudsey and his use of a "suicide lead" - maybe the collequial name for this type of lead tells you why they are a bad idea? Plus it does't matter how careful someone is handling this kind of lead, its use may not cause the death of the user but it will very easily kill the inverter.
 
A use a 230v motor contactor with 2 normally closed and 2 normally open contacts. All the 230v electrics is connected to the normally closed contacts fed by the inverter except for the on grid battery charger. This is connected together with the input grid feed and the contactor coil to the normally open contacts. When grid power is connected, the contactor switches on and everything is connected to the grid. The 12v loads are fed by the battery which has the charger connected as well.
A third normally closed contact cuts the 12v relay which disconnects the inverter.

My inlet power connection is an industrial type connector with extra pins that I use as a warning that it's connected when I switch on the ignition even if there is no 230v power on the extension cord.
 
Mr and Mrs Tupcox said:
Hi I want to connect my vans 240v system to inverter. So looking at fitting a transfer switch ,which has 240v hook up lead off site and inverter, so van will have 240v off grid.
Don't want run separate cables and sockets.
If any has done this please advise and recommend a transfer switch.
Click to expand...
Would something like this work?

Manual Switch

Regards,
Del
 
Last edited:
Ok, quick summary ...

You want to be able to select between using an Inverter to power an AC device or the Hookup to power the device.
#1 requirement over all others is the method of switching MUST be "break before make" - You have to ensure the AC outlet of the Inverter never connects to the AC Supply. If you do ... BOOM!

Then you have to choose between Automatic and Manual Switching.
There are lots of manual switches available. The ones you have been shown tend to switch a single circuit. You can also get a Consumer Unit mounted switch which you could fit in such a way to switch the whole van AC over.
An Auto Switch is - IMO - a far better option as you can just use things without overly thinking about it.

You need to be able to switch both the live and neutral wires between the two circuits - this is pretty standard for any switch specified as a AC 2-1 Switch. The PE wire doesn't get switched and would usually be connected to both sides.
You should also avoid having the Mains Charger on the switched circuit and also if you have an electric heater you probably don't want to have that on the circuit either. Yes you can remember to turn them off, but why not have set up to not have to remember to do so (or there may be someone else who used the van who doesn't know they have to do that).

In terms of installing it, just install it correctly and safely. Not going to give any hints and tips on that part as electricity can kill and if you don't know how to install the switch, you need to get it done by someone who does.
 
wildebus said:
That switch will do both live and neutral, so would be ok.
Click to expand...
No it doesn't. The switch in the link only has a pair of contacts. Both off on 0 or one or the other on the 1-2 position. It needs 2 levels of contacts to cut both lines.
 
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