shower isolator

Hi

I have just finished testing my fathers house prior to upgrading some circuits and a cu change.

He has a 6mm cable supplying a 9.5 kw shower, When I tested at his pullcord, I noticed greening at the line conductors into the terminals?

The position of the pullcord is 10cm from the side of the shower enclosure.

Is this moisture causing corrosion or arcing? I am inclined to cut ina new iso outside the bathroom?

What is your opinion of pullcords for showers or lighting?

I am looking at adding a fan as well so there wil be a lot to chase out with 2x iso, and a switch.

Found a few interesting things while testing;

1. 30 amp breaker 6mm cable supplying 1 x double skt in kitchen!(must fed from old cooker iso position?) zs0.20

2. cooker fed from 2.5 spur off ring under cupboards into a jb, then into 6mm into dual cooker isolator box with socket on side, feeding cooker in 6mm then skt feeding hob ignition. half way up flex there is a taped connector block!!!!

Dad! Been there 20 yrs at least. zs 0.26 all round ring give or take 0.03.

The other house ring ok results, apart from a few bad readings in two bedrooms for the lighting everthing apart from above ok.

What would u recommend changing?

I am going to def add 3x smokes, 2 timer fans, bad lighting cables, rcd dual board.

mark

Think the green is just copper oxidising with the moisture from the bathroom. Green not too bad - black we need to worry!

You know to use the Crabtree shower isolators?

I would agree with apache on the greening of earth.

It looks like some rather bad practice with the other circuits.

All terminals should be suitable, as should the overcurrent protective devises for each circuit.

I always install 10mm cable for showers now, 6mm are ok if the length is a relatively short run.

I now use the crabtree 50amp shower pull switch, its far easier to terminate larger cables into its a little bigger than most shower isolators but well designed for use.

With the addition of a fan the moisture levels in the bathroom should not rise high enough to cause a problem even if the pull cord is only 10cm from the shower enclosure.