Quick electrical question

[John Rumm]

Yup, it says:

"This standard is applicable to transformers and power supply (linear) with internal operational frequencies not exceeding 500 Hz. This standard used in combination with Part 2-16 for switch mode power supply units (SMPS) is also applicable to power supplies with internal operational frequencies higher than| 500 Hz. Where the two requirements are in conflict the most severe take precedence."

If the manufacture states that it is SELV (and note USB PSUs have a bit of a reputation for being anything but in some cases!), then the socket would probably be ok so long as >3m from the edges of zone 2.

[GB]

This was meant to be a quick question, but I refer you back to the OP, which seems to have been ages ago:

"Is there such a thing as a triple width surface mounted back box?"

I am not going to hack a hole in the tiles, as I have no spares.

[John Rumm]

Sounds like he needs a rethink then :-)

Carbide or Diamond saw in a multitool soon makes nice neat square holes through tiles, and the flange on a dry lining box is quite wide:

e.g:

and (I think the one on the right was the after the fact addition):

[SH]

I have actually used a carbide blade in a multitool for cutting holes in existing tiles....

only trouble is the blades are not cheap and they wear out qucikly agains ceramics......

Also you have ot watch your speed and heat, I've seen the blade glowing red hot in tiles and its the heat that kills the blade.

Also you have to be careful not to accidentally catch the end of the abrasive edge on the tile or the tile cracks

[John Rumm]

The saxon ones seam pretty good IME, and are significantly cheaper than some:

Depends a bit on the type of tile - normal clay backed ones are easy, but very hard porcelain take much more cutting. A trigger spray bottle with water will help on really hard stuff and extend blade life.

[ARW]

John, you have really pissed me off with that photo - in the nicest possible way.

I normally take one look at a double socket/light switch etc and instantly know the brand.

It has a BG look about it but it's not the BG range my wholesaler sells.

So help me out pal. What make is it?

[John Rumm]

GET Ultimate (now part of Schneider)

I quite like those, decent size terminals that are also colour coded (old and new) as well as LNE embossed. Nice switch action and not too many edges to catch dust.

[ARW]

Ta.

And here is one you have probably never seen before

I first saw them at Coventry Elex 2 years ago.

[John Rumm]

True, not seen them...

Seems like a good way of funnelling condensation into the earth terminal in kitchens!

[Roger Hayter]

In the case of 8mm porcelain tiles values of soon approaching infinity.

[John Rumm]

If cutting really hard tiles in situ, then I normally use a Norton "hard materials" continuous rim diamond disk in an 115mm AG, with a strategically placed vacuum nozzle to catch the dust. You can then do most of the work with a plunge cut, and use the diamond segment saw in the oscillating tool to get into the corners.

Having someone you work a water spray helps keep it cool and cutting as well.