What’s the best way to earth the 220 V output from the MultiPlus?
This depends on the application, but for a fixed, off grid install you need a ground stake. The earth is then connected to the ground stake, and an RCCBO / Earth leakage trip installed on the Multiplus AC output.
And what if it’s a mobile setup, like in a campervan? Off-grid.
For AC out, then the ground is connected to the Vehicle chassis, an RCBO is still used. On the input side, an isolation transformer is usually required.
On the input side (shore power), surely an RCD has to be fitted anyway? So where would I need an isolation transformer?
On the shore side, the RCBO is in the distribution pillar. You need the isolation transformer to keep your earth leakage low, isolate your setup from the shore side earth/neutral potentials. Sometimes they are not needed, but some RV parks have very low level trips , <10mA, ant those are easy to trip out.
It depends on how the electrical system is designed.
An isolation transformer is not necessarily required in an RV.
In some cases, earthing the chassis can even be counterproductive; in others, it may be permitted or mandatory.
With appropriately earth-fault- and short-circuit-free wiring, you can leave the chassis unearthed if the equipotential bonding is carried through the sockets (with the chassis acting as a floating shield).
In other applications, the TT is installed directly in the input circuit, while the chassis is also connected on the secondary side.
Or it is connected to the equipotential bonding along with the input RBCO.
The precise earthing method and how it is implemented should therefore always be planned with the help of a qualified professional!
Hi,
In my view, an isolation transformer is needed in caravans/motorhomes because of the 12 V supply from the vehicle, or for converting 230 V to 12 V for the vehicle/caravan.
I’ve installed a mains changeover switch. As soon as shore power is available, everything running on 230 V is fed directly through the blue CEE socket. When it’s unplugged, it switches over to the inverter with a break in the supply. I think if you use a MultiPlus or something similar and connect it to the UPS output, that should work directly too. I’ve connected PE to the chassis, either way. I installed an internal 30 mA RCD for the 230 V. Yes, I know: that means two RCDs in series, one in the vehicle and one external. Doesn’t matter—you need one in the vehicle if you’re generating 230 V from a battery. Personally, I don’t know the regulations, but it works. And don’t forget to test everything to make sure it trips, etc.!!!
Question:
Are you using the output, or running in parallel with the mains?