question

Carl avatar image
Carl asked

Grounding?

Have questions about grounding in the system below.

The system is to be built in a motorhome.

Why should Multiplus be grounded in the negative bus bar?

And with what cable area in that case?

And which cable area should the ground cable to the Smart bms be?

None of these cables are longer than 3m.


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For full view of the system

https://www.victronenergy.se/upload/documents/MultiPlus-3KW-230VAC-12VDC-600Ah-Li-Lynx-Smart-BMS-&-distributors-Cerbo-GX-touch-generator-MPPT-Orion-Tr-Smarts.pdf


Grounding
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1 Answer
kevgermany avatar image
kevgermany answered ·

In this type of setup when you're off grid there is no ground. So the multiplus has a relay to connect ground and neutral automatically. All the negative connections need to be at the same zero volt potential.Otherwise meters etc. don't work and you may have a dangerous electrical fault. Afik also needed for earth leakage detection.

Should at least be an indication of how to size it in the manual/installation instructions. But there shouldn't be any current through it, so cable rated for 10A or higher should be enough/overkill. My Easysolar us connected with 4mm, not sure what that is in US guages..

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Ground, earth and electrical safety


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