Stupid and lucky?

mejinks · 30-12-2008, 23:00

The old ceiling rose for the light was on its way out, so I decided to change it this evening. Imagine my surprise, when on inserting the lightbulb, it immediately lit up

It turns out that someone me had forgotten to make sure the light switch was actually off before commencing work. Lesson learned methinks.

Stay safe this year guys.

Darrin · 31-12-2008, 01:17

Meh, my time in the Navy as an electronics technician I ended up working on energized circuits all the time. Everything from 5VDC 750A all the way up to 10,000VAC at microwave frequencies (10GHz). I've been zapped by every version of electricity humans use at least once each. Including 440V 3 phase 400Hz. That was the one that hurt the most. The concussion I received from slamming into a steel bulkhead 20+ feet away from where I was working lasted about a week. The bruises on my back took a little longer to go away.

I agree with mejinks. Stay safe (and alive) folks. Electricity can and will bite you. Hard.

Burble · 31-12-2008, 10:46

I got a zap off a 3 phase supply as it was on the way down. That hurt like hell! 240v isn't all that bad to be honest.

Garp · 31-12-2008, 10:56

A mate of mine was painting a ceiling for a charity somewhere in Northern Ireland (details escape me.) It was an old house, end of a terrace IIRC. Group of them were painting the room. They thought all lecy was off.

*paint paint paint paint paint*
*arm brushes up against wires*

*ZRGGGGG*

Off they go and find the fuse box, removing all the fuses, just to be safe. None of the fuses was labeled or showing any indication what was for what.

*paint paint paint paint paint*
*arm brushes up against wires*

*ZRGGGGG*

He hits the floor, having fallen off the step-stool he was using (he's a tall guy barely needed step stool.)

Cue big surprise, all fuses were out. They go hunting around the house again, checking each cupboard and find some more fuses in a fuse box hidden in the kitchen. "Oh" they think and pull out those fuses too.

*paint paint paint paint paint*

*arm brushes up against wire*

*ZRGGGGG*

He hits the floor again, by now getting a little peeved and also even more confused. They've checked everywhere in the house after the first failure.
Someone goes next door to speak to a neighbour to find out where their lighting ring fuse is.
"Oh yeah, you do realise your lighting ring comes through to our fuse box, don't ya?"

Muban · 31-12-2008, 13:54

Did you get Huddy lessons for Christmas?!!

Pumpkinstew · 31-12-2008, 14:21

You'd be quite unlucky if you did yourself a serious injury from a domestic supply, especially a lighting ring as the fuse on that is normally smaller.

Not that I'm advocating live working in any way.

We used to hear horror stories about the EHV gear that steps down from National to regional grid though.

Darrin: Military equipment oscillating at 10GHz? I've no idea what that could be

I hope you were protecting yourself from the fields. A MW pencil beam at that frequency can knock someone unconscious. Even 100kW will give you a very bad week.

Darrin · 01-01-2009, 01:49

Quote:

Originally Posted by Pumpkinstew

Darrin: Military equipment oscillating at 10GHz? I've no idea what that could be

I hope you were protecting yourself from the fields. A MW pencil beam at that frequency can knock someone unconscious. Even 100kW will give you a very bad week.

Remember I was an electronics technician specializing in radars. Hence the 10GHz. They were also direction fire control radars, so I'm VERY familiar with the pencil beam aspect. Ours was a 2.5 degree 2KW. I also worked on the 48E surface and air search radar. That was one to be scared of. 250KW on LOW power scan!! You REALLY don't want to be around the power supplies on that one when they kick it up to high power!! (and no, I'm still not allowed to say what high power setting is in watts. Just leave it at that on high power there was in excess of 5,000A of current in one section)

I was also one of the unlucky ones to see what a plasma arc from a failing power supply will do to a human body. The investigators

figured there was in excess of 12,000 amps arc across mid-air with a guy standing in the path. Other people in the room said it sounded like they were just down range of the 16 inch guns on the Missouri. They were only able to send the guy's boots home as the rest of him had vaporized. I will NEVER forget that smell...

A Place of Light · 01-01-2009, 14:47

I know it's an oldie (and probably a pearoast), but this thread reminded me of this:-

Feek · 31-12-2008, 17:05

To be fair, if a bulb has gone or a rose has failed, it's pretty tricky to tell if the juice is on or off especially if it's one with multiple switches, or is a pull switch for a bathroom light.

phykell · 01-01-2009, 15:07

If you're a DIY type, you should switch off the corresponding lighting circuit at the consumer unit. If you really must work on a circuit which may be switched by a single pole, you should always check with a decent tester rather than one of those dodgy screwdrivers with a neon inside.

Here's an example:

http://www.fluke.co.uk/comx/show_pro...en&product=ELT

31-12-2008, 01:17	#2
Darrin Dirteh Kitteh Join Date: Jan 2007 Location: Hiding out in Mormon Country Posts: 1,629	Meh, my time in the Navy as an electronics technician I ended up working on energized circuits all the time. Everything from 5VDC 750A all the way up to 10,000VAC at microwave frequencies (10GHz). I've been zapped by every version of electricity humans use at least once each. Including 440V 3 phase 400Hz. That was the one that hurt the most. The concussion I received from slamming into a steel bulkhead 20+ feet away from where I was working lasted about a week. The bruises on my back took a little longer to go away. I agree with mejinks. Stay safe (and alive) folks. Electricity can and will bite you. Hard. __________________ A bullet may have your name on it, but shrapnel is addressed "to whom it may concern".

31-12-2008, 10:56	#4
Garp Preparing more tumbleweed Join Date: Jun 2006 Location: Hawaii Posts: 6,038	A mate of mine was painting a ceiling for a charity somewhere in Northern Ireland (details escape me.) It was an old house, end of a terrace IIRC. Group of them were painting the room. They thought all lecy was off. paint paint paint paint paint arm brushes up against wires ZRGGGGG Off they go and find the fuse box, removing all the fuses, just to be safe. None of the fuses was labeled or showing any indication what was for what. paint paint paint paint paint arm brushes up against wires ZRGGGGG He hits the floor, having fallen off the step-stool he was using (he's a tall guy barely needed step stool.) Cue big surprise, all fuses were out. They go hunting around the house again, checking each cupboard and find some more fuses in a fuse box hidden in the kitchen. "Oh" they think and pull out those fuses too. paint paint paint paint paint arm brushes up against wire ZRGGGGG He hits the floor again, by now getting a little peeved and also even more confused. They've checked everywhere in the house after the first failure. Someone goes next door to speak to a neighbour to find out where their lighting ring fuse is. "Oh yeah, you do realise your lighting ring comes through to our fuse box, don't ya?" __________________ Mal: Define "interesting"? Wash: "Oh, God, oh, God, we're all gonna die"?

31-12-2008, 13:54	#5
Muban Shoes, Boobs & Corsets Join Date: Jul 2006 Location: The fastest town in Scotland Posts: 1,882	Did you get Huddy lessons for Christmas?!! __________________ well, not to put a too fine point to it, he was discovered.. in the lounge

31-12-2008, 14:21	#6
Pumpkinstew Absinthe Join Date: Oct 2007 Location: Mostly Oxford, Sometimes Bristol Posts: 1,156	You'd be quite unlucky if you did yourself a serious injury from a domestic supply, especially a lighting ring as the fuse on that is normally smaller. Not that I'm advocating live working in any way. We used to hear horror stories about the EHV gear that steps down from National to regional grid though. Darrin: Military equipment oscillating at 10GHz? I've no idea what that could be I hope you were protecting yourself from the fields. A MW pencil beam at that frequency can knock someone unconscious. Even 100kW will give you a very bad week. __________________ Get old, or die tryin' PSTEWREVIEWS - Chunks of Meaty Reviews, Mixed with Your Five a Day of News, Comment and Opinion, Floating in a Broth of Suspect Grammar and Seasoned Liberally with Mixed Metaphor. Tasty. Last edited by Pumpkinstew; 31-12-2008 at 14:23.

31-12-2008, 17:05	#9
Feek ex SAS Join Date: Jun 2006 Location: JO01ou Posts: 10,062	To be fair, if a bulb has gone or a rose has failed, it's pretty tricky to tell if the juice is on or off especially if it's one with multiple switches, or is a pull switch for a bathroom light. __________________

31-12-2008, 10:46	#3
Burble Rocket Fuel Join Date: Jul 2006 Posts: 7,826	I got a zap off a 3 phase supply as it was on the way down. That hurt like hell! 240v isn't all that bad to be honest.

01-01-2009, 14:47	#8
A Place of Light Absinthe Join Date: Dec 2007 Posts: 1,247	I know it's an oldie (and probably a pearoast), but this thread reminded me of this:-

01-01-2009, 15:07	#10
phykell Vodka Martini Join Date: Sep 2007 Posts: 833	If you're a DIY type, you should switch off the corresponding lighting circuit at the consumer unit. If you really must work on a circuit which may be switched by a single pole, you should always check with a decent tester rather than one of those dodgy screwdrivers with a neon inside. Here's an example: http://www.fluke.co.uk/comx/show_pro...en&product=ELT __________________