Electrical Isolation

StevieB · 26 Sep 2006

I have moved house and now have a cellar rather than a workshop, which means all my tools are potentially accessible to my two small sons. In an effort to keep them safe I wanted a universal switch that I could fit into the cellar ring (I will be fitting a new one so wiring not a problem) so that I could shut off all the sockets and prevent little fingers starting the table saw etc in my absence. Does anyone know of a suitable product? The only thing I could find on screwfix was for 440v.

Not currently a problem since the cellar as it stands, 12 ft x 16 ft and 12 ft x 12 ft has a grand total of...... 1 double socket! But I aim to rewire soon ahem, I mean modify the existing circuit (if 1 socket can be called a circuit!) so any helpful pointers to a suitable item appreciated.

Cheers in advance!

Steve.

Scrit · 26 Sep 2006

The voltage doesn't matter so long as it is rated at least 250 volts - the 440 volts says to me that the one you found was a 3-pole unit, but for single phase you'd just end-up with a spare switch pole in the box. A 20A or 32A 2-pole rotary isolator, such as this

Klockner Moeller one will do the job of isolating a mains spur if mounted on a plywood or chipboard backboard and they are pad-lockable (it's the type used on machine tools).

If you need to isolate a ring main then you'll either need a 4-pole isolator or you'll need to ring off the isolator switch and then run a 4.0mm cross section spur from the consumer unit to the isolator (depending on distance)

Scrit

OLD · 26 Sep 2006

A shower isolator switch wired as above ring main cables to output heavy cable from input to distribution mcb is another way if you have a suitable mounting position (red light shows its live).

StevieB · 26 Sep 2006

Ah, many thanks. So this should be fine? :-

http://www.screwfix.com/app/sfd/cat/pro.jsp?id=18739&ts=78028

Cheers,

Steve.

engineer one · 30 Sep 2006

ages ago i bought a cable from a company called INEXCESS in
soton, it is a kind of isolater that works in the garden so you can't
kill yourself with the mower etc.

easiest way to describe is an extension cable with a key in it.
remove the key, no power,

will see where it is over the weekend, and give you a brand.

paul :wink:

neilc · 30 Sep 2006

The easiest thing is to pass the wiring for your sockets through a 230v contactor. The coil of the contactor is then wired through a key switch. You will be able to pass 4 radial circuits through the contactor, just remove the key when you leave and everything goes dead. I think its safer with kids around, judging by my young fella

. If you decide to do it this way and need help with the circuit just let me know.
Neil.