1st fix - best cables & back boxes? Also, separation of data and 230V with a wall?

[Alan Ambrose]

A couple of misc 1st fix questions if I may...

 

Are there better mains cables than Doncaster Cables earthsure e.g. a LSZH version?

 

Who makes the best quality ~45mm metal back boxes?

 

I know that in a cable tray scenario data & mains should be separated. What about within walls - we're planning to separate with dividers, but will undoubtably need to cross mains cables at right angles with data/ELV at some point?

 

Can I use something like this for mains + data? From the pic, I think the two compartments are separate.

 

 

Yes, I know ... ask your proper electrician - but I'm an EE and feel happy making  these choices. Also, our 1st recommended & qualified electrician on site did this, and won't be back again:

Yes, that's gaffer tape as blanking plus wood screws holding the new CU front plate on FFS ... seems to me that's qualified but not competent. 

[garrymartin]

I'll go first...

 

Mains cables - Doncaster Cables are really good. Earthsure? Ask your electrician. Some love it, some hate it! You might find LZSH versions of T&E with a sheathed CPC, but they may not be accredited for use in the UK. Plenty of LZSH without a sheathed CPC. Prysmian cable is really good too. I'd be happy with either.

 

For a single residential, low-rise property, the price uplift for LSZH is difficult for some to justify, but it may be important to you. I'd rather invest the difference in much better, interlinked smoke and heat alarms...

 

From an interference perspective, this separation of data and mains cabling comes mainly from commercial installations. Unless you run your CAT6 UTP parallel to the cable for your induction hob for tens of metres, you're very unlikely to have an issue.

 

Now, from an electrical safety perspective, don't run low-voltage and mains cabling in the same conduit, and don't have them feed into the same accessory box. Any damage to the mains cabling could end up with mains voltage on your low-voltage cable runs, so keep them separate.

 

Where it is possible, in a parallel run, keep them at least 50mm apart. But other than that, just don't worry about it. Crossing at 90 degrees is perfectly fine.

 

Whilst you could therefore use something like your image (assuming they are physically separated boxes) I've never really liked the aesthetic and lack of control over the gap between the data plate and the 230v mains socket. I'd always use separate back boxes.

 

My back boxes of choice are Appleby metal back boxes and plastic cavity / dry-lining boxes, or Selectric or Niglon if looking for fire-rated metal cavity boxes.

[ProDave]

I would not use LHZS cable, I find it horrible stuff to strip and use.  Standard PVC for me.