RV schematics/diagram specfic to UK code

[EllaBella]

Ella, i know you wrote previously not to use the chassis for ground purposes due to corrosion issues, but looking at the inverter/charger manual suggests an additional earthing wire from the unit to the chassis. On the SCC, it indicates an earth wire from the negative busbar to the chassis. Ive heard folks talk about an earth wire from the frames of the solar panels to the chassis. There are so many opinions out there all conflicting.
I dont know for sure, which of these diagrams would work best?

View attachment 8925View attachment 8926

If it works for people to use the chassis as a floating ground then that's great, but personally I'd still prefer to have a closed system using pure copper cable. It's safer than if you come into contact with a positive contact point while touching the chassis. On a 48v system you can get a significant shock. On 230v AC you could get a dangerous shock.

I'm guessing people do this to save money on copper cables? It really isn't that much more of an effort to just run a positive and negative.

 

[John Frum]

If it works for people to use the chassis as a floating ground then that's great, but personally I'd still prefer to have a closed system using pure copper cable. It's safer if you come into contact with a positive contact point while touching the chassis. On a 48v system you can get a significant shock. On 230v AC you could get a dangerous shock.

I'm guessing people do this to save money on copper cables? It really isn't that much more of an effort to just run a positive and negative.

I think there is confusion here between chassis ground and chassis return.
I don't think jim wants to use the chassis as the return path.
just wants to bond the chassis to the negative terminal.

 

[EllaBella]

I think there is confusion here between chassis ground and chassis return.
I don't think jim wants to use the chassis as the return path.
just wants to bond the chassis to the negative terminal.

The first diagram shows a floating chassis ground with a return to the negative and the second shows grounding to just the negative.

With the first, using a ground to the chassis and then returning to the negative will become a short if a positive connection comes into contact with the chassis. So if a person happens to be in contact with the chassis and also a positive, depending on the circuit being shorted, this could be dangerous.

The second is a lot safer as it bypasses the chassis and uses cable to return the ground to the a negative bus bar directly.

 

[Solarfun4jim]

The first diagram shows a floating chassis ground with a return to the negative and the second shows grounding to just the negative.

With the first, using a ground to the chassis and then returning to the negative will become a short if a positive connection comes into contact with the chassis. So if a person happens to be in contact with the chassis and also a positive, depending on the circuit being shorted, this could be dangerous.

The second is a lot safer as it bypasses the chassis and uses cable to return the ground to the a negative bus bar directly.

Thanks ella. What exactly do you make of this below, from an inverter manual?
"This product is a safety class I device (supplied with a ground terminal for safety purposes). Its AC input and/or output terminals must be provided with uninterruptible grounding for safety purposes. An additional grounding point bonded to the chassis is located inside the terminal cover of the product."
Do you think that means vehicle chassis or could they be meaning the chassis of the unit, ie its casing? If it simply meant the casing, i'd imagine it would already be installed?

Plus, there is this info on another inverter...

Thanks to DZL for that.

 

[John Frum]

The first diagram shows a floating chassis ground with a return to the negative and the second shows grounding to just the negative.

With the first, using a ground to the chassis and then returning to the negative will become a short if a positive connection comes into contact with the chassis. So if a person happens to be in contact with the chassis and also a positive, depending on the circuit being shorted, this could be dangerous.

The second is a lot safer as it bypasses the chassis and uses cable to return the ground to the a negative bus bar directly.

On the other hand the chassis bond means that a short to the chassis will hopefully trip the ocpd and clear the fault condition.