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Kaplan78 avatar image

Earth Ground Breaker in Van?

The manual is saying that the AC side of my Multiplus 2000 should have an earth ground breaker. However, is this neccessary, or useful in a van installation? That breaker is pricy for sure but if it improves safety in the van I’m all about it.

This is the breaker that Victron seem to refer to - https://www.wolfautomation.com/ground-fault-circuit-breaker-2p-c-curve-15a-27827/

Confused since there is no true “Earth” ground in a van. Greatful for any guidance. Thanks!

Grounding
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kai avatar image

A residual current device (the RCBO you linked is an example) doesn't require an absolute (i.e. physical earth) ground reference. The relative (i.e. chassis) earth is sufficient for the RCD.

It works off the difference in current between the live and neutral - any difference greater than X ma (30mA is one of the standard values) will cause the RCD to cut the circuit.

Note: if there is a difference, it means that there is a leakage somewhere - somewhere other than safely running through the insulated AC wiring that its supposed to be. In most cases this is likely through the (relative) earth system.

The idea is that rather than waiting until the fault current is high enough to open a normal breaker, any sufficiently large leakage would open the RCBO as well. (i.e. a RCBO has both a normal breaker function and a RCD function)

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Noia avatar image

How can you ground something through the cassis as the point of contact are rubber wheels which kind of defy the purpose of grounding through the cassis?

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First, I am not an expert, a professional, or even particularly knowledgeable. But in answer to your question


Electricity 'wants to return to the source' not specifically to earth ground. The grounding system in a building allows this to happen. In a vehicle, the source (is often) the battery. Chassis ground allows electricity a return path to the battery (if your battery negative is connected to chassis ground), because electricity doesn't actually want to 'go to ground' it wants to return to the source, earth-ground, and chassis-ground can just be convenient ways for it to get there.

Kaplan78 avatar image

Yes correct, my AC will be grounded to the chassis, and I was going to put in standard breakers for the AC. However Victron recommends this type of breaker with "earth ground." I don't know what value it brings and I'm inclined to not use them. I have looked at other pro installs using Victron and they don't. I was just hoping someone could shed some light on what value they bring to a van install. Thanks!

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kai avatar image

I'm assuming that there is a chassis earth though?

If there is a fault that livens the chassis you would want the breaker to put a stop to it.

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