Mains in Zone 0?

As stated in tabbytroll's link to the wiki....

What is the moron up to? Trying to pull Adam's chain?....

Is it permitted now to run a mains cable through zone 0? It's SWA, and there's no junction in zone 0, just a cable passing through.

Thanks.

Seems to me that'd be a trip hazard* given zone 0 is the /interior/ of the bath tub or shower basin :)

In zone 1/2 allowed so long as not serving the zones and RCD protected:

• unless the coal will cover the cable!

:) It's under the bath

Electric showers are in zone 0, their cable likewise. This one passes through to feed something outside the zones.

NT

I referred to cables "not serving" only because you said the cable was "passing through". 701.411.3.3 also applies to cables serving the location.

Can we have a photo of a shower and cable to it in zone 0 please?

Still looking for a copy of 701.411.3.3.

??

NT

If you screw the bath panel on, so that it requires a tool to remove it, the area under the bath isn't zoned at all and you can have whatever you want under there.

SteveW

Showers are typically installed in Zone 1 (i.e. directly above Zone 0)

It basically says you need RCD protection at <= 30mA for circuits serving the location, or those just passing through if they do so in zones 1 or 2.

Which confirms, as did John Rumm, that Zone 0 is the /interior/ of the bath or shower basin. The /basin/ is not the /cubicle/. Above the basin is Zone 1 where most showers are fitted.

When we were living at my parents' holiday cottage, the roof leaked and water drained down the bathroom wall (between the plaster and the stone wall) and dripped into the dining room.

So I had to work out how to take the bath side off to see if there was a leak from one of the pipes. It was a long enough job that it could*definitely* not be described as tool-free, so it would have satisfied the "not zoned at all" condition.

It was slightly alarming to be working a couple of inches from a thick bundle of 30A T&E cables to/from the ring main which the builder had routed under the bath, as being the shortest route from one room to another. This was long before bathroom zones, but I presume he'd checked the building regs that were in force at the time. I hope the insulation never cracks as the cable gets older, leading to moisture getting to the wires and potentially causing a short.

What is the life of the outer cable and inner wire insulation of standard grey T&E cable? This would have been installed in the late 80s.

It's next to the fan belt.

Probably about 75 years unless under maximum load for long periods of time or you let an apprentice near it.

I was once involved in the testing of a large compressor with a 3.5MW

Except for cable that suffers the "green goo" or is exposed permanently to sunlight, it seems to have an indefinite life. Cables installed in the '70s seem as good as new.

SteveW

I remember once reading a test report written by one of my colleagues about 45 years ago.

They had built a prototype railway rolling stock dc chopper based on a string of thyristors. The assembly was placed on a substantial metal bedplate in the test area. It was connected to the power supply through a water fuse. This consisted of a plastic bucket filled with water, having a couple of submerged cable connectors and a thin wire between them. For safety, the bucket had a wooden lid with a heavy weight sitting on it.

When the inevitable fault occurred, the fuse blew with some force, creating a waterspout which lifted the lid high in the air. Unfortunately, on the way back down, the heavy weight was faster then the wooden lid, and it wedged itself between the cable connectors, re-making the circuit. This would have been bad enough on its own, but with all the water sloshing around on the bedplate, the supply was now both shorted and earthed.

I believe it took some time to get supplies restored, and there were no intact thyristors left.

Chris

You are asking an awful lot from a length of cable on a rotating planet rotating around a sun to be "exposed permanently to sunlight"

:)

Yup. The diagram I looked at showed under the bath/shower as zero, which I now know is wrong. So it's in zones 1,2, which are no problem.

NT

it doesn't normally disintegrate unless overloaded, or some eventually fails if in direct sun for decades.

NT