Inverter through ring main

[Bailey58]

I've connected the inverter to an isolated 13a socket to give me more practical feed but it led me to thinking is it safe to connect a 2000W modified sine wave inverter to the EHU input on the van? Simply to energise all the sockets rather than rely on the one outlet. Is there some delicate stuff in the mains system which makes this inadvisable and would a pure sine wave and/or some sort of surge protector as in a computer set up make any difference. Just thinking!

Hello, Rolfarris has gone off the gas bottle and now messing with the van again.

 

[motorhomelover]

I've connected the inverter to an isolated 13a socket to give me more practical feed but it led me to thinking is it safe to connect a 2000W modified sine wave inverter to the EHU input on the van? Simply to energise all the sockets rather than rely on the one outlet. Is there some delicate stuff in the mains system which makes this inadvisable and would a pure sine wave and/or some sort of surge protector as in a computer set up make any difference. Just thinking!

Hello, Rolfarris has gone off the gas bottle and now messing with the van again.

It is not recommended as there are some major safety issues
You could fine your pride and joy going up in flames should the mains and the inverter be power at the same time
If it was that easy I would be offered at the construction stage

A little knowledge is very dangerous leave well alone and to an expert electrician

 

[Landy lover]

I have seen a three position master switch fitted in some vehicles central position is all off right hand is inverter left hand position is EHU effectively isolated the input circuits but allows all 13 amp sockets to be powered from which ever source you choose - what the wiring is I have not a clue but there is a way out there somewhere

 

[Bailey58]

It is not recommended as there are some major safety issues

I guessed there would be. :Blush:

You could fine your pride and joy going up in flames should the mains and the inverter be power at the same time

I appreciate that but with only one input on the EHU that wouldn't be possible.

If it was that easy I would be offered at the construction stage

I can think of things I'd like at the construction stage but we don't get them. :Sad:

A little knowledge is very dangerous leave well alone and to an expert electrician

Just asking. :thumb:

 

[haganap]

Yes Rolf

What you want to do can be done.

I have done a similar thing on mine. Basically you need to fit a relay. I don't have mine connected straight in to the external EHU socket. Mine is broken from inside, when I fire up the inverter it will fire up all sockets and the microwave.

Techno has put a fantastic illustrated guide to how to do it on the forum. Ill see if I can locate it for you. It really is great to heat milk for breakfast in the microwave. :thumb::thumb:

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[haganap]

Here you go Rolf. I followed this to a tee, Andy really knows his stuff.

Broken Link Removed

 

[pappajohn]

if you go down this route you need a manual or auto power source selector so the inverter is turned off when h/u plugged in.

a foolproof way would be to fit a h/u plug to the inverter output wires......cant have two plugs into one socket...so you couldn't accidentally leave the inverter turned on/plugged in when on hookup.

and you need to turn off your charger....no point in inverting 12v to 230v and use the power to recharge the battery...which it will never do as the inverter will drain batteries faster than the charger can charge them.

 

[Mel]

Here you go Rolf. I followed this to a tee, Andy really knows his stuff.

Broken Link Removed

Paul I also think Andy realy knows his stuff.

Where is he from ?

Mel

 

[Bailey58]

That looks like the way to go, my neighbour had an auto electrician do a similar job on his Trannie conversion but I'm off on Monday for Dover so think I'll wait 'til I get back. :Cool:

 

[haganap]

if you go down this route you need a manual or auto power source selector so the inverter is turned off when h/u plugged in.

a foolproof way would be to fit a h/u plug to the inverter output wires......cant have two plugs into one socket...so you couldn't accidentally leave the inverter turned on/plugged in when on hookup.

and you need to turn off your charger....no point in inverting 12v to 230v and use the power to recharge the battery...which it will never do as the inverter will drain batteries faster than the charger can charge them.

Not if you do it Andys way John. I thought of the way you mention. I think Olley does it this way. But looking at it theres too many failings, like forgeting to turn off inverter. Doing it Andys way, it matters not if you accidentally leave your inverter on, plug in EHU or any another gotchas.

Paul I also think Andy realy knows his stuff.

Where is he from ?

Mel

He's from Leeds I believe Mel, :thumb:

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[G8WVW]

... but it led me to thinking is it safe to connect a 2000W modified sine wave inverter to the EHU input on the van?

If you are unplugging the EHU cable to plug in your inverter into the same socket then I do not see any problems. Things to be aware of:-

1. Your van RCD may continually trip if the inverter output is 'centre-taped earth' rather then the UK standard of earth tied to neutral. Some inverters you can change this. Guess try it as it is and see what happen
2. If your fridge automatically selects its energy source, it will select the inverter rather than gas unnecessarily flattening your batteries.
3. Your battery charger will start being fed from the inverter, trying to charge the batteries that the inverter is being powered by. Think about that one for a minute!
4. Technically you've lost your earth's reference to 'earth' ... but that happens for most of us using on-board inverters or generators. Being pedantic, you should have an earth spike in the ground.

Cheers.

 

[TheDogMan]

I have a 3 way switch, normal / mains / invertor and a seperate inverter switch, so to go one invertor I have to switch twice this then fires up all 4 mains sockets but not the mains auto changeover on the fridge, the downside is that making all the wiring live uses some power even on the ones not being used, International RV's Coventry did mine, it is handy not being limited to a particular socket:thumb:

 

[Reallyretired]

My inverter is wired so it powers all the sockets, but does not power the fridge, heater and most particularly not the charger. It can be changed over manually or left to switch over automatically if the ehu power fails.:thumb:

 

[pappajohn]

If you are unplugging the EHU cable to plug in your inverter into the same socket then I do not see any problems. Things to be aware of:-

1. Your van RCD may continually trip if the inverter output is 'centre-taped earth' rather then the UK standard of earth tied to neutral. Some inverters you can change this. Guess try it as it is and see what happen
2. If your fridge automatically selects its energy source, it will select the inverter rather than gas unnecessarily flattening your batteries.
3. Your battery charger will start being fed from the inverter, trying to charge the batteries that the inverter is being powered by. Think about that one for a minute!
4. Technically you've lost your earth's reference to 'earth' ... but that happens for most of us using on-board inverters or generators. Being pedantic, you should have an earth spike in the ground.

Cheers.

been through this before.....

a ground spike provides an earth route from an installation back to the power source if no other means is provided.

it wont earth a motorhome using an onboard gennie or inverter as the power source is unearthed anyway.

oddly, my generator is inbuilt and when running shows neutral, phase AND earth using a Martindale socket tester