I want to install an inverter to my caravan to run off the solar system and batteries when not on a hookup. But I'm aiming to have a switch over so that all the sockets run of the inverter not just the output from the inverter.
My question though is, whilst in the caravan the inverter will take care of any earthing faults as it's an isolated insulated system and there's no risk of true earth, but what about the external power point. At this point there's a high likelihood of finding true earth if an appliance faults in the awning?
Would the RCD in the fuse box take care of it or should I create a earth bonding point, or should I stop over thinking it, I know I should probably speak to a sparky.....
anything that produces any heat will flatten the batteries in a very short period of time i.e. maybe 10 mins max
if it just for watching tv then you can get a 12 tv, if you change all your bulbs over to led ones that makes a huge difference to how long your leisure battery will last, not sure what else you would want/need to run.
I would avoid the use of inverters if at all possible. I totally agree with Marg6 about anything that produces heat, as that would be a real battery killer. Inverters also drain power in themselves, even when there is nothing plugged into them, so unless you intend to have a really massive battery bank I would definitely give them a miss.
If you want to go off-grid, aim to have everything 12 volt powered rather than mains, and do all your cooking and heating by gas, and the same for your fridge. Solar panels, unless truly massive, are fine for keeping a battery charged up while it's not in use, but they don't provide much power in themselves. They don't put as much into a battery as an inverter on its own would take out, and of course they only work at all in daylight hours.
some things do need mains power.. in my case a camera battery charger and laptop charger.. i used to use a small 300 watt inverter and be careful how i used it..
but in this day and age such things as lithium batteries exist and the easiest solution are self contained power stations or solar generators..
to answer your original question the only true earth is a long metal stake driven into the ground.. few people bother with such things though most modern appliances are made of plastic some only use two core cable..
the only downside to using "modern" technology is it dosnt come cheap but it does make some things possible that previously were not..
quite why i feel guilty for pointing this out i dont know.. but in this forum i do..
Quote: Originally posted by saxo1 on 19/4/2023
There is still the risk of a shock from an inverter if used to power all the sockets.
saxo1
maybe but i think its a pretty small one.. i power all my sockets from an inverter.. i think its safe enough for me.. but others may feel different..
as i say the only true earth is a long metal stake driven into the ground.. the option is there but i doubt many people do it..
this earth factor kicks in with all portable 230 volt generators.. gas or so called solar powered devices.. these things are in common use and the numbers are growing.. i doubt many people drive a stake into the ground though it kind of messes up the convenience factor :)
Most portable suitcase type generators have a floating neutral and as such don't require earthing unless they have been modified,the only proviso is that if using more than 1 class 1 appliance connected at the same time
then it should be earthed.
It's OK to use multiple double insulated class2 appliances.
saxo1
The caravan chassis is bonded to the earth in the caravan consumer unit and that is earthed to the site earth which should be earth rods. So with EHU connected any fault is quickly isolated by the MCB or RCD.
If you connect the invertor to the existing sockets it may be bonded to the caravan chassis which will not be be earthed. A cable fault will make the caravan chassis live and the fault will not be isolated so it will remain live.
Quote: Originally posted by navver on 19/4/2023
The caravan chassis is bonded to the earth in the caravan consumer unit and that is earthed to the site earth which should be earth rods. So with EHU connected any fault is quickly isolated by the MCB or RCD.
If you connect the invertor to the existing sockets it may be bonded to the caravan chassis which will not be be earthed. A cable fault will make the caravan chassis live and the fault will not be isolated so it will remain live.
some people bond their inverters to the caravan chassis i think that is a bad idea and have not done so with mine.. apart from the metal chassis caravans are mostly wood and plastic and so most things that get plugged in are plastic cased....
in theory there should be a real earth but as as far as portable 230 volt power supplies go there mostly isnt.. convenience is winning the day..
There are a lot of appliances in a caravan that are class 1 and are connected to the protective earth conductor to the chassis, anything with a 3 core cable is class 1, microwaves/toasters/fridges/electric hobs etc which may have extraneous metal parts that you may come in contact with.
saxo1
As has been suggested I would go down the solar power station route, I have got a small 300w Ecoflow power unit that I use for overnighting in services to run my 240v TV and DVD player and charge phones/laptops etc. You can buy bigger ones up to 2kw that will power kettles and air fryers and such like.
Quote: Originally posted by Big Roy on 20/4/2023
As has been suggested I would go down the solar power station route, I have got a small 300w Ecoflow power unit that I use for overnighting in services to run my 240v TV and DVD player and charge phones/laptops etc. You can buy bigger ones up to 2kw that will power kettles and air fryers and such like.
here is a good deal on a bigger power station.. i just bought one for general usage..
Please excuse my ignorance , I'm non techy my excuse is I'm 79yrs of age.From what I've read of your post I should be ok to survive 3to4 days without 240v hookup.
I have just aquired a teardrop caravan, and my van has a leisure battery charged up to 12.7 I can cook on gas , torches and battery lamps . Plus thinking of getting power pack to charge my mobile.
Does that make sense ?
Quote: Originally posted by Stoky on 21/4/2023
Please excuse my ignorance , I'm non techy my excuse is I'm 79yrs of age.From what I've read of your post I should be ok to survive 3to4 days without 240v hookup.
I have just aquired a teardrop caravan, and my van has a leisure battery charged up to 12.7 I can cook on gas , torches and battery lamps . Plus thinking of getting power pack to charge my mobile.
Does that make sense ?
not really no, when all you need is a car charger to charge your phone, or you can buy solar chargers that will keep your phone going that cost well under £50 rather than the hundreds a power pack would cost, just change your lights in the teardrop to led ones and that will use a tiny fraction of the power from your battery, even connecting a 50watt solar panel would keep the leisure battery topped up and could be done for under £50
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Topic: Inverters, Potential Difference and Earth
via mobile 18/4/2023 at 12:14am
