Inverter - Earthing

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otronics
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Inverter - Earthing

Post by otronics » Tue Jan 08, 2019 2:00 pm

I have an inverter I am fixing up.

It has a single UK plug socket although the earth isn't connected to anything.

Should it be?
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Re: Inverter - Earthing

Post by ericmark » Tue Jan 08, 2019 4:35 pm

Not a straight forward answer, what you have is an IT supply, similar to shaver outlet, and when powering a single item the danger is very small, however as the number of items increases so does the danger, it is like the birds on the power cable, since they only touch line, then no current flows, so they are OK, where the danger arrives is where there are more than one fault.

The idea of an earth is should a fault happen it will automatically disconnect. Be it a MCB, fuse, or RCD some device will open.

So an inverter powering a room full of PC's will need an earth, but an inverter powering a single PC could get away without it.
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Re: Inverter - Earthing

Post by kellys_eye » Tue Jan 08, 2019 5:02 pm

It's straight forward in the sense of having a single socket outlet that should (ideally) be used for a single item of equipment. Keep it that way and an earth is not necessary due to the 'floating' output.
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Re: Inverter - Earthing

Post by OnlyMe » Wed Jan 09, 2019 8:23 pm

kellys_eye wrote:It's straight forward in the sense of having a single socket outlet that should (ideally) be used for a single item of equipment. Keep it that way and an earth is not necessary due to the 'floating' output.
Unless the OP tried to power up a boiler.
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Re: Inverter - Earthing

Post by otronics » Thu Jan 10, 2019 11:09 am

The inverter is being used in a van so only small items will be plugged into it.

Just seems odd that obviously the live and neutrals are connected but the earth isn't - not even to the inverter chassis.

What if the travel kettle shorts and the metal casing becomes live?
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Re: Inverter - Earthing

Post by ericmark » Sat Jan 12, 2019 12:52 am

If there is no earth then there is no neutral, you have line 1 and line 2.

So if there is a fault and L1 connected to the body of a device then no problem, and L1 becomes the neutral,
and if there is a fault and L2 connected to the body of a device then no problem, and L2 becomes the neutral,
however if you have two items and with one L1 connects to earth and other L2 connects to earth then there is a problem.

So one class 1 item no problem many class II items, no problem, two class I items there is a small chance of a problem, many class I items high chance of a problem.
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Re: Inverter - Earthing

Post by otronics » Sat Jan 12, 2019 9:44 am

Thanks for this.

So should I ground the earth pin to the chassis of the inverter, and then the inverter to the chassis of the van?
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Re: Inverter - Earthing

Post by OnlyMe » Sun Jan 13, 2019 7:24 pm

It would be normal to connect the chassis of the van to the earth terminal on the inverter.
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Re: Inverter - Earthing

Post by otronics » Thu Jan 24, 2019 1:17 pm

Or could I connect the earth terminal on the 3 pin UK plug connection to neutral on the 12v battery terminal?
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