Earth conductor size problem

7 lives left meow · Posted: Fri Apr 14, 2006 6:25 pm Post Subject: Earth conductor size problem

Hello.

I am in the process of bonding and cross bonding my house.

However whilst it is fairly straightforward I have come up against a problem.

My old consumer unit is a WYLEX 4 way wire fuse type (now converted to MCBs)

The 16 mm earth cable cannot fit in the earth block inside the consumer unit the holes are too small.

Could I use 2 smaller cables or will i need to replace the consumer unit?

The original earth cable looks to be only approx 6mm

Any advice would be much appreciated.

Best Regards,

JohnD · Posted: Fri Apr 14, 2006 6:51 pm Post Subject:

Time you bought a new one

But it is possible to separate the strands and poke some into two different holes.

the brass earth block in those is only held to the inside of the backbox with a couple of screws, so I suppose it would be possible to put a bigger block in. If you had a metalclad, it could even by bolted to the outside.

7 lives left meow · Posted: Fri Apr 14, 2006 7:06 pm Post Subject:

Thank for the advice.

I might give the Bigger earth block a try!.

Best Regards,

Lectrician · Posted: Fri Apr 14, 2006 7:07 pm Post Subject:

I would fit a new CU - Ideal opertunity.

Most people upgrade the CU, and do the bonding at the same time, not vica-versa.

7 lives left meow · Posted: Fri Apr 14, 2006 7:28 pm Post Subject:

The reason I am going for just the bonding at the moment is that I am having a loft conversion(the builder told me his electrician will charge me extra if the bonding is not done)
I am just trying to save a little time/expense
I would feel more confident letting the electrician carry out the CU Change

Best Regards

JohnD · Posted: Sun Apr 16, 2006 11:59 pm Post Subject:

Out of interest, I looked at an old brown Wylex Standard 6-way at the weekend, You can fit a 16mm earth into the brass block. A close fit, but it will go. the holes at the ends are slightly bigger than the others (which fit a 10mm). The neutral block took 16mm too.

I am pretty sure the later Ivory Wylexes fit 16mm with ease.

Beware that on the older Wylex Standards, the brass terminals and screws for the incomers are exposed to the touch when you remove the cover. Turning the main switch off leaves them still live and exposed. Wylex used to provide little plastic covers FOC if asked.

Steve · Posted: Mon Apr 17, 2006 11:48 am Post Subject:

strange many people say on here that that old wylex's with wooden backs were only ever rated to 60A. Ours said 100A on it. And the fuse tops could take 10mm² cable at a squeeze.