RCD for inverted 240v mains - any qualified electricans?

[cb1rocket]

Hey all

I have just set up my flourscent tube light in the shed, and seeing its a metal body strip light and the shed being metal. I haven't installed it on the beam yet...... safety comes first. I have been naughty and only used a twin wire with a plug on the end and plugged into the inverter which is then ran off the 12v battery I have. So I didn't touch it (leaning off the bike) but just to test to see if its works and it does.

So really once I have wired a 3 wire cable into the strip light as such, I want something that is going to cut off the supply should a fault occur, ie an insulation fault or a damage wiring shorting itself.

So the question remains is an RCD enough? I know caravans run such a thing but don't know how they are wired or used as such.

Anyone with any tips or advice?

Cheers

[cb1rocket]

bumy bump!

[Codemonkey]

RCD's work by detecting a difference in the current flowing in the live and neutral conductors. Normally, they should be the same. If however a fault condition occurs and some of the current is able to take a different path to the return (via earth which is connected to neutral at the substation), then the trip will activate.

In a system with an inverter, unless the neutral has been connected to earth (unlikely), then there are not many fault conditions that could allow the fault current to return to neutral via another path.

In short, I don't think fitting an RCD will have any effect unless your inverter has its neutral output connected to earth. Since it is probably not the case, you could probably touch the live conductor and not get a shock (don't try it though!!) since there is no return path for the current back to the inverter's neutral connection.

[cb1rocket]

[Pete.]

Sounds like you are going way over the top. The easiest way to make sure no current can be tranferred from light to metal beam is to hang the light from the beam using something non-conductive instead of screwing it on directly.

Personally, I would use your setup without hesitation. I'd fix the light to the ceiling and make a shelf about waist height by the door to sit the battery on, screw the inverter on the wall above the shelf, at about face height, and hang the leads with battery terminals down to the shelf so I could walk through the door with a fully-charged battery, plonk it on the shelf and drop the power leads straight on the terminals. Job done.
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[cb1rocket]

thanks Pete, also is the RCD more than sufficient? Thats what nobody seems to be able to answer. Thanks for the set up idea, mine is a system with a solar panel on the roof, therefore the battery stays put while being topped up during the sunny days. The shed is only used occasionally along with an 85Ah leisure battery.

The tube light in the shed is the best bit, as its super fecking bright, just what i wanted

Might upgrade the inverter for power tools and the like.

[Pete.]

Yeah I think the RCD would be fine. Personally, I wouldn't have bothered even with that - I'd just fuse the striplight correctly.

I don't think you'll get far trying to run power tools off an inverter. Say you had a 1000w drill - that would pull at least 83 amps out of the battery.

Better off sticking to using it for lighting, and use battery powered tools, gas powered soldering iron that can double as a heat gun, old calorgas fire for heating etc or buy a cheap small silenced genny that you can heave outside if you really have to for 240v power.
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[cb1rocket]

Yeah probably best use a genny, after some multimeter reading its roughly that for every 1 watts of 240 mains use is about 0.1 amps!

so yes a 600 watt drill is going to take 60 amps an hour! Although i would probably get away for short uses.

[kramdra]

its now summer'ish. So either you work on your bike very late at night or you have no windows!!!!

problem solved. Make a window.


double insulated light?
low voltage CCFL?
LED? (have one spare if you want it)



you shouldnt use for tools, anything above say, 50A load and you need to be careful how long your using it for. + inverters cost ££££££££. It wants to be charged straight away - solar is too slow and the uncharged part can rot.

Gennys cost a lot, + fuel. noise and smoke :/

Extension lead from your house? hand tools!? (easier for me than carrying my 60 meter lead out!). Push bike down to house? (I assume this is for fixing bike)



I should get a picture of my garage. Previous owner had a 240v tube wired with bare copper wire at head height. Dangling from the ceiling from a couple loops of wire. I dont think he is still around...

[cb1rocket]

solar panel provides enough juice for what I need and the shed is only occsaional use. Yes I know the summer is here but sometimes night falls and I need some light working into the dark!

I still try and do most of my power tools down an extension line.

Main need is for the light and the odd sod, so ideal for what I need, I have seen 12v strip, LEDs but they are no where near as bright