Inverter Earth

[joffo81]

Hi fellow Navarians,

Any auto electricians out there that can offer me advice?
I have recently upgraded the power in my camper trailer. I now have dual batteries (wired in parallel of course) to power all my accessories through merit plugs. I have also installed an inverter with a circuit breaker to an outlet on the outside of my camper.

My question is: do I need to earth the inverter to ground in any way? The instruction booklet said nothing about earthing. There is obviously an earth wire and pin in the 240v cord coming out of the inverter but how does this work? Would the inverter box be double insulated or something?

Any light that could be shed on the topic would be great as I have never used an inverter before.

 

[bods]

Generally they are double insulated, all you need to do is hook up 12v power and ground and you're good to go

 

[Farmer Joe]

I didn,t earth mine and have had no problems
fj

 

[terryc]

None of the inverters I have are double insulated. They are all a PCB mounted in all alloy tube construction.

I have absolutely no idea if they need to be earthed. although all mine have an earth post with wing nut. Nothing in the instructions says anything about it. To me it makes no sense. If you are worried, stick a core balance safety unit on the 240V side, then if one wire is grounded, it will click off.

To my way of thinking, it you earth the inverter and there is a fault/voltage on the surface of your 240v device, it will provide a circuit through you and the earth/ground. No earthing and no circuit.

FWIW, try a web search and you'll get even more confused. The only people I've come across telling you that it must be earthed are electricians, who will also tell you that each installation has to be set up by an licensed electrician.

 

[joffo81]

I have done some searching on the net and Terry was right - I am even more confused!

Some people say earth it some say don't. Some say by earthing an inverter which is electrically isolated (as in my case I think?) you will only increase the risk of electric shock!

My inverter seems to be a basic type. It has a positive and negative connection on the DC side. I have wired the positive through a fuse to the pos battery terminal and negative to the negative battery terminal. The AC side has 2 outlet plugs and an on/off switch. I have plugged in a portable RCD (circuit breaker) and then my appliances will be plugged into this. I have read that the RCD is useless unless the inverted is earthed but I can't see any harm in leaving it there anyway!

I have also read that with the set-up described above, I should only run one 3 pin appliance at a time off the inverter but as many 2 pin appliaances as I like. I do not understand why this is the case.

The instructions that came with the inverter say nothing about earthing so am leaning towards leaving my set-up as is and not using an earth stake (which is less work of course). BUT I really want to make sure I have a safe set-up for myself and my family.

Do any fellow Nav men use earth stakes with their inverter set-ups or is it a waste of time?

 

[bods]

I've only got a basic 300w one I think, and I'm pretty sure I've never used anything from it with an earth pin anyway but for charging laptops, etc it works fine. What are you planning on running from it? I've never bothered earthing mine either

 

[Krankin]

I dont have mine earthed to that stud and wingnut....I do have an RCD powerboard plugged into the unit and the RCD works, tho I have had it tested to varify it.

just be safe with all your gear plugged into the output side.

 

[joffo81]

Thanks fellas. I only plan to be charging phones and batteries and laptops and maybe running a fan or something along those lines. Sounds like I am doing the right thing and will leave it unearthed and leave the RCD in place.