Short circuits from tails to meatal cased CU's

Deleted member 9648 · Nov 3, 2015

Following on from http://www.electriciansforums.co.uk...m/106222-watch-out-im-fitting-plastic-db.html I wonder how many of us have ever seen a fault from tails to a metal cased CU, I haven't in 35 years. Whether a TT and a live case....or a TN and a real bang up! Has anyone?

plantpot · Nov 3, 2015

No never in 30 years

Midwest · Nov 3, 2015

..........perhaps the electrician never lived to tell the tale! A while back I came across an old metal clad CU, with a TT supply. The installer had taken the precaution of cutting a 2" hole, for the tails to enter. The tails had been position in the centre of the hole, so they didn't coming into contact with the burred metal edges.

Richard Burns · Nov 3, 2015

Most of the metal CU's I see are now old and I have not seen a short from the tails to the enclosure even on some very bad installations.

Deleted member 9648 · Nov 3, 2015

All of which suggests there is no need to lose any sleep over a properly installed metal cased TT CU!

DNO · Nov 3, 2015

Properly installed? you mean with an all insulated up front RCCD. You know it makes sense!

Deleted member 9648 · Nov 4, 2015

DNO said:
Properly installed? you mean with an all insulated up front RCCD. You know it makes sense!

It does to a point, but the fact remains that it will be a departure, if you are going to accept that then the departure may as well be an insulated CU in the first place!