pflowers

Hi, I have a log cabin in the middle of some woods and I want to have a electrical supply via my generator. I will have just a light and a double socket for powering tv etc.

Initially I was going to wire it up so the generator socket ( round three pin type ) goes straight to a junction box that then spurs off to power the light and socket. I then got a bit worried thinking I should have some sort of consumer unit / RCD to protect against a shock as the generator has no such thing.

I have now been told that I cannot do it this way as a generator has a floating earth and cannot be connected to an RCD ?

Any electricians out there know if this is correct or can offer any advice ?

Cheers.

Peter.

03-CTR

i don't think you have a problem if you're using double insulated appliances. just make sure your kettle is either a gas or plastic type and you'll be fine.

sparkykev

People run touring caravans on gennies, and they'd be fitted with rcds, and as rcds don't require an earth to function, i can't think of a problem.
If it was me i'd fit a consumer unit with an rcd, and fuse the socket and lights via there own mcb, ie, 16A and 6A.

Remember the earth has to be connected.

mr & mrs carlos uk300

I'll ask my hubby when he comes in from work, he's a sparky.

03-CTR

but why go to all the expense if you're only powering a tv and a light??

a breaker is only a reuseable fuse and an rcd is simply there to prevent injury/death through an electric shock. given that a tv is double insulated and a light/lamp can be too then how is an earth fault going to cause a problem and create a need for one in the first place??

mr & mrs carlos uk300

peter,sparkykev is correct when he says that you dont need an earth for your rcd,as this measures any inbalance between the live and neutral only.if your only going to be using a light and a television(double insulated),then personally i wouldn't bother. saying that,is this log cabin waterproof? remember that the stuff your going to be using should really be fused down to the correct rating.
i, personally would fit a consumer unit with each of your circuits going back to the relevant circuit breaker,but also fit an earth rod outside and connect it to the earthbar inside of the consumer unit! some may think this is over the top,but where electricity is concerned, you can't be too careful..trust me!


good luck carlos(superspark)

pflowers

Thanks for all the help!..................although I am not sure if I am any the wiser !

03-CTR

carlos is probably right in advising an earth rod tbh as it will be safer.

with regard to the rcd thing, an rcd works by sensing the current in the two conductors. if there is any imbalance, say if you're receiving an electric shock, then the thing will trip faster than the current can kill you. they're regulation equipment for your ground ring and shower for obvious reasons but last thing i heard they were going to become regulation for the upstairs ring too (if not already). the reason i said that they would not be necessary was because you're only running a tv from the supply. as it's nigh on impossible for you to receive a fatal shock from one then you'll be ok with just the plug top fuse.

as for the consumer unit i guess it makes sense to tidy things up and get a small one with a main switch and say 2 mcb's (one for your lights and one for the sockets). if you do want an earth then as carlos says get a earth rod, whack it into the ground and then connect it to the consumer unit.

hope this helps

pflowers

03-CTR / Carlos, what is the reason for the separate earth ? What will happen if I just connect the consumer unit earth to the generator earth ?

Peter

Tim-Grove

Connecting the earth of the consumer unit to the neutral of the generator would probably give a lower earth loop value than the earth rod as it would be an easier route back to the generation source. It would be no different than using a PME system, all new services now are PME unless the customer specifies they want a separate earth due to a high neutral/earth value on the on the suppliers side.

pflowers

Thanks Tim, so if I put a link in the socket that plugs into the generator from neutral to earth that would work ok, would I need to disconnect the earth wire from the earth pin that connects to the generator or leave it connected ?

Peter

Tim-Grove

Ignore what I just said mate, thinking back on it now the point of generation still needs staking down to earth even if the point of service is PME’ed. So you might just as well do as the other guys said and knock an earth stake in and run an earth cable to the consumer unit.