Electrocution in bath

[Chris Oates]

went wrong ?

[ben]

The head of the shower had somehow become live, which suggests the earth on the shower was faulty. He was presumably by holding a tap (unless stray capacitance was enough to do it?), and when the head fell into the water and he was a convenient path to earth.

It sounds like there was no RCD. To make matters worse, someone had replaced the fuse wire in the fusebox with a bit of leftover copper, though I doubt that the correct fuse would have saved him.

I would say that the real problem was the lack of a good earth on the shower. Another reason to DIY.

Personally, I have a 30mA RCD and have taken a 6mm^2 from the earth on the shower to the main 10mm^2 equipotential bond on the incoming water, just to be doubly safe. Incidentally, does anyone know if me having done this violates the regs, provided I disconnect it before an earth loop test is done?

Ben.

[Mike Harrison]

None of the faults mentioned in the article would seem to be capable of causing this - fuse type is irrelevant as is the pull switch. Not sure what they mean by 'box behind the cord'...

For something like this to happen, the only scenario I can think of is that the shower and its supply pipe was not earthed, and there was a live-to-water short in the shower, and either the (metal) bath was earthed (to provide enough voltage gradient in the water), or it was a plastic bath and the victim touched an earthed tap (or plughole) while the bath water was live. Even then it does seem a little improbable.

[Grimly Curmudgeon]

--------------------- "He told the inquest he found several faults with the shower. The pull switch to turn it on was jammed so that it was always live, the box behind the cord was the wrong sort and the fuse on the wall unit had the wrong sort of wire in it.

The faults in the switch could cause a short circuit and the copper wire in the fuse meant it would not cut off the electricity as it was designed to, he said."

---------------------

Sounds like some of the ones I've found in the past couple of years.

[Michael Mcneil]

Interesting to note no-one mentioned that the people who did the maintenance did the inspection.

[Andrew Gabriel]

causing this - fuse type is

the shower and its

shower, and either the

it was a plastic bath

live. Even then it does

I am amased that the contractor who was responsible for maintaining the property was called in to investigate what was wrong with the shower. That would be like asking Jarvis to investigate the cause of the Potters Bar rail incident. As you say, this requires multiple faults if the information as reported is accurate.

[Chris Oates]

I've had a 'death at work' which was suspected electrocution and HSE demanded an immediate inspection but didn't inquire if the Co. were one that had done work for us previously.

Southern Electric did a major 3 phase re-wire for us and ran out of red tailing, subsequent failure to tape up the tails resulted in phase/neutral reversal on a lot of equipment used by the public. I found the fault in a routine test next day - if PartP comes in I won't be an acceptable installer/tester and won't have equipment made available. But...I'm fully certified to inspect & commission Kiddie rides and Simulators - this was done the sensible way ...a long proveable history, proper equipment, work sampling and (of course) a good working relationship with HSE - I call them once in while knowing they like a day out & get myself assessed by them - nothing better than sheaves of green paper to wave at Insurance bods.

[John Smith]

There is a Darwin Award about two workmen who got electrocuted in the US when scaffolding they were carrying hit overhead power cables killing them both. The local council sent a team out to investigate how the tragedy occured.. two council workers picked up the scaffolding poles and... well, you can work out the rest.

John.

[BigWallop]

Ouch !!! One of the older showers with an earth bond to the hose attachment no doubt. I never trusted these things. The new instant showers are allowed to keep the outlet insulated from the hose, but the older ones were fitted with a bonded copper or brass ring within the thread of the outlet to try and keep this type of thing from happening. Obviously it doesn't.

[Wanderer]

causing this - fuse type is

the shower and its

shower, and either the

or it was a plastic bath

live. Even then it does

The story in Ananova doesn't make it clear whether or not SE actually had done any work there since the tenants moved in. It seems somewhat unlikely, given the coroner's comments..

[Wanderer]

Interesting to note that people like jumping to conclusions without all of the evidence. The story does not say whether or not SE had done any work there previously. There was, however, a clue in the coroner's comments.

[PoP]

Do you know something we don't? What's this "if" business?

PoP

[Darryn]

Gees if you poms didn't use those horrible instant shower things stuff like that wouldn't happen

You have delightful rules about not having a 240v outlet near the basin for a razor or hair drier (only an isolation xformer) and pull cords to turn the lights on and off

But you are quite happy to have 240V sitting inside a plastic box inside the shower recess

The mind boggles really

Darryn

from downunder

-- remove two eyes to reply!

[BigWallop]

But the gubbins inside the unit should be so insulated from moisture ingress, that things like this shouldn't happen on a properly installed instant shower unit.

[Dave Plowman]

Or an immersion heater inside a copper cylinder connected to the bath or shower by copper pipe?

[Andy Dingley]

Well it's a great idea until it goes wrong....

Anyone know how common this sort of accident is ?

-- Die Gotterspammerung - Junkmail of the Gods

[The Natural Philosopher]

Yup. AND of course if you have earh bonding, and someone finds the earth stake and hooks it over the incoming mains :)

There are many strangenesses in the safety regs. Making sure things that you can toucjh are solidly erthaed is fine..as long as (a) they are in fact solidly earhed and not a gian conductor amnd

(b) the other hand is not likely to touch something equally solidly live..

In the old days before earths and RCD's we used to get minor shocks off lots of stuff due to unearthed metal cases and frayed insulation. As long as you didn't touch something earthed, and not much was - that's all it was - a minor shock.

MMm.

[The Natural Philosopher]

Rare enough to be worth reporting it would seem.

[Andy Wade]

Part P (if/when it comes into force) will only apply to houses. Yours sounds like an 'at work' situation so comes under the Electricity at Work Regulations.

[Andy Wade]

It won't violate the regs, but it does seem an odd thing to do. It would have been more logical to run your 6 mm^2 earth back to the main earth bar in the CU - thus making a 'high integrity earth' similar to one of the Section 607 options for earthing of circuits with high protective conductor currents.

What's much more important (and what no-one has mentioned so far in this thread) is the local supplementary bonding in the bathroom. That's what _should_ have prevented the electrocution in this case. But there probably wasn't any, judging by what we know about the general condition of the installation.

BTW there's no need to disconnect either main or supplementary bonding when doing earth fault loop impedance tests on final circuits within an installation (Zs). The only time you need to disconnect the bonding is when doing a measurement of the loop impedance external to the installation (Ze) or when measuring the resistance of an earth electrode. See page 79 of your On-Site Guide.