EHU/Inverter earth have I missed something?

[growly_bear]

Hello everyone.
I installed a Renogy 2000W inverter which has the uninterrupted power pass through function.
When I plug in a circuit tester I get this. Surprised as an earth is present.

I've just let say "adjusted" the wiring in the Hymer so that all sockets are on one radial and the Combi + EBL + fridge are on the other radial.
The Combi+EBL+fridge radial are powered straight out of the consumer unit (RCD+C10) so they function only when on EHU.
The other radial (with the sockets) is powered from the inverter. The inverter input is fed from the other connection on the consumer unit (RCD+C10)

When I test the sockets in the Hymer with no EHU I lose the earth and get this. When on EHU the earth returns.

Is this normal? I can't understand how a camper on 4 tyres can ever earth!

ATM the invertor is not bonded to the chassis.

I'd be really interested in your feedback please!

Also, why is there an earth when the plug is fitted directly in the invertor and not when in a simple extension? Very puzzling to me!

Thank you

 

[pappajohn]

On hookup the earth is part of the mains supply..... The van could be floating in the air but the earth is still there.
On the inverter there is no earth in the same respect as hookup earth.
To provide an earth it needs connecting to either the vehicle chassis or a separate copper/brass earth rod driven into the ground and connected by a suitable cable

 

[Dargish]

You should have an RCD between the inverter and your sockets. There is no protection from shocks otherwise.

 

[growly_bear]

You should have an RCD between the inverter and your sockets. There is no protection from shocks otherwise.

I'm new to the world of inverters and their safety. So if I plug a hair dryer directly into the inverter there is no shock protection? Or is attaching to the existing sockets in the van somehow changing the protection?

 

[berni109]

Unfortunately you need to do a lot of reading and youtubing to understand what is going on when you introduce an inverter into the electrical system of a van.
As long as all the appliances you use when the inverter is providing the power are double insulated you should be all right.

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[Lenny HB]

You should have an RCD between the inverter and your sockets. There is no protection from shocks otherwise.

That will only work if the inverter allows the neutral to be bonded to earth.
You can do that on good inverters like Victron, cheaper inverters often not possible I don't think it is possible on a Renogy.
Cheaper ones often have a centre tapped output so if you boned the neutral to ground you would either kill the output or only get 120v.

 

[Richard n Ann]

I'm new to the world of inverters and their safety. So if I plug a hair dryer directly into the inverter there is no shock protection? Or is attaching to the existing sockets in the van somehow changing the protection?

It's safe to use. There is no shock protection with an earth but the outputs on the inverter won't travel to earth. You could only get a shock by touching both the outputs (L&N) at the same time.. Very unlikely

 

[Lenny HB]

You could only get a shock by touching both the outputs at the same time.

Done that a few times in the house, it hurts.

 

[Tombola]

Lenny HB do you agree with this ?

 

[Just smiffy]

Done that a few times in the house, it hurts.

I concur…. And your the professional…

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[DABurleigh]

I used to offer a lot of motorhome technical advice over the years, but the trickiest issue for me was over the best provision of inverter earth against a number of risk scenarios. As my brain went around in circles until it turned to mush, I finally resolved the issue to my satisfaction simply by vowing never again to try solving it.

Dave

 

[Lenny HB]

Lenny HB do you agree with this ?

View attachment 1040531

Yes, providing you have moved the internal link on the Victron inverter to bond the neutral to earth. They ship with the earth unbonded.

 

[DABurleigh]

I used to offer a lot of motorhome technical advice over the years, but the trickiest issue for me was over the best provision of inverter earth against a number of risk scenarios. As my brain went around in circles until it turned to mush, I finally resolved the issue to my satisfaction simply by vowing never again to try solving it.

Dave

Should anyone care to follow in my footsteps, I suggest starting with the assumption that motorhomers aren't going to drive an earth spike into the ground each time they stop, and then to picture themselves stepping outside with a freeze-frame just at the point of their goolies being in the path of lowest impedance from chassis to ground.

Dave

 

[Lenny HB]

Should anyone care to follow in my footsteps, I suggest starting with the assumption that motorhomers aren't going to drive an earth spike into the ground each time they stop, and then to picture themselves stepping outside with a freeze-frame just at the point of their goolies being in the path of lowest impedance from chassis to ground.

Dave

You have obviously not met many of our weird Funsters.

 

[growly_bear]

Thanks one and all for your valued help.
I'll make sure everything is double insulated.
I'll dare now to plug a hair dryer in

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[Dall]

That will only work if the inverter allows the neutral to be bonded to earth.
You can do that on good inverters like Victron, cheaper inverters often not possible I don't think it is possible on a Renogy.
Cheaper ones often have a centre tapped output so if you boned the neutral to ground you would either kill the output or only get 120v.

Sunshine Solar inverters come as standard with switched N+E bonding selection.

 

[Dargish]

Nice read here about the regulations:

https://www.thevanconversion.com/post/this-is-how-to-ground-van-conversion-electrics-the-right-way

 

[growly_bear]

Nice read here about the regulations:

https://www.thevanconversion.com/post/this-is-how-to-ground-van-conversion-electrics-the-right-way

That's a good read and provides much reassurance.

I watched a Greg virgo youtube video who said that he was doing one on earthing and grounding, but I can't find it!

I also watched where a chap connected the invertor negative to the neutral on an RCD with a relay to interrupt when on ecu, which will be my next step. But I'm still reading...

 

[Dargish]

That's a good read and provides much reassurance.

I watched a Greg virgo youtube video who said that he was doing one on earthing and grounding, but I can't find it!

I also watched where a chap connected the invertor negative to the neutral on an RCD with a relay to interrupt when on ecu, which will be my next step. But I'm still reading...

Inverter/chargers will often handle that earth/neutral bond when disconnected from EHU for you. I'm eying up a £400 one with that feature, it will simplify things greatly.