I was asked weather or not you may use 240V on site buy using an R.C.D as opposed to 110V
2007-02-06 06:57:26 · 9 answers · asked by fletwat 1 in Science & Mathematics ➔ Engineering
no, no 240v tools.
2007-02-06 07:07:29 · answer #1 · answered by Mark k 4 · 0⤊ 0⤋
Below 50Volts has been decided as a safe voltage,
you know those yellow 110V site transformers, well they have a centre tap, this means that they give out two 55v "lives" so if you get a shock to earth you only get 55 volts.
You could get a 110v shock but you have to get hold of both "lives" (not likely) (and stupid).
I know 55v is over 50 but thats the way it is, and now were supposed to be on 230v which would make it nearly right
Thats why you can't use 240v tools.
An RCD limits current only and it wont stop you getting a 240v
shock if you get across Live and Neutral (you'll feel that)
PS, I wrote
An RCD limits current only and it wont stop you getting a 240v
shock if you get across Live and Neutral (you'll feel that)
The important bit there is, "across Live and Neutral"
all those electrons don't care if they are going through your drills motor winding or YOU.
The only thing that will will stop you getting a shock Live to Neutral is the fuse or circuit breaker, but probably by the time the circuit has overloaded .............you'd be dead!
The fuse or breaker is designed to be a weak link in a circuit, it is only there to save the cable from overheating, thus preventing a fire.
To stop people being electrocuted you need to provide an earth or circuit protective conductor, if a fault to earth develops the idea is that the circuit draws loads of juice through the CPC and takes out the fuse PDQ
However, if you are the path to earth, your skin resistance (20000Ω) stops enough juice flowing in the circuit to take out the fuse quick enough so, you get a belt.
An RCD does monitor the juice in the L and N
If it's the same in both, all ok, if not, Where's it gone? through you, to earth?
so to be safe it gets cut off in at best, 40mS
2007-02-06 17:43:21 · answer #2 · answered by shedfull 1 · 0⤊ 1⤋
You would do best to consult your local Health & Safety Executive. They will give you the correct ruling.
My first thoughts would be that this would be OK, but I'm not 100% certain.
Bear in mind that if using the 240v RCD arrangement wasn't legal and anything went wrong there you would be liable.
----
PS A comment below said
"An RCD limits current only and it wont stop you getting a 240v shock if you get across Live and Neutral (you'll feel that)"
Sorry, this is wrong. An RCD detects any imbalance between Live current and Neutral current. This would be caused by e.g. you touching live and drawing more than 20mA to Earth. The RCD trips and turns off the voltage in about a fifth of a second. You might just feel it before it goes off.
2007-02-06 15:13:18 · answer #3 · answered by efes_haze 5 · 0⤊ 0⤋
Your question doesn't make sense. An RCD protects against earth leakage so you can use on a 240v circuit or indeed, if in the US, an 110v circuit. You don't say what you are trying to do or if you’re in the UK or elsewhere so please clarify.
2007-02-08 10:19:05 · answer #4 · answered by Anonymous · 0⤊ 0⤋
U.K.you can use 240v as long as it is run on a step down transformer. converting it to 110v
2007-02-06 15:02:57 · answer #5 · answered by Anonymous · 0⤊ 0⤋
i believe it is legal... but it depends on the size of the site you want to work on, and the discretion of the site foreman. on a big site you probably wouldn't have any 240v sockets to use anyhow, as they only supply 110v.
2007-02-06 15:06:28 · answer #6 · answered by nufftuffnuss 2 · 0⤊ 0⤋
No - iee 16th edition states 110V only on a construction site see bs 7671
2007-02-08 17:03:13 · answer #7 · answered by Mark G 2 · 0⤊ 0⤋
I asked the same of our Health and Safety team a couple of weeks ago and got a flat NO as the answer. 110 only.
2007-02-08 04:42:09 · answer #8 · answered by Mr Custard 1 · 0⤊ 0⤋
No .It has to be 110v
2007-02-06 15:19:55 · answer #9 · answered by Anonymous · 0⤊ 0⤋