Electrical Adventures In This Lifetime.

[BillyBobThai]

As I will be building a house in the next few months, every thing I have read so far in the Electrical Wiring posting, will be helpful. I am in the process of reading through all of the postings here on electrical wiring. I am now at page 6 of 25. One thing that has occured to me, is that I have many funny/humorous experiances that occured to me over a 20 year period, working in a lead acid battery factory. I have had many times been shocked, the most being 850 volt DC. This trully hurts. The good Lord has looked over me many times as I did stupid things. When working with large, (8000AH at 8 hr. rate), lead acid lead acid batteries, large amperage is involved. When things go wrong they go wrong they go wrong fast and loud. Batteries are usually full of hrdrogen.

I would like to see some posting of things that have happened to others. This will be fun for some but also be helpful to others.

Robert

[hanno]

Many years ago I walked into the workshop at my parents' home. Saw a naked wire hanging from the ceiling and, wanting to clean up, grabbed it. It was only after I flew across the workshop and picked myself up off the floor that I found out that the wire was live and the maintenance staff used it to check light bulbs

[simon43]

I have often wondered whether 'getting used' to electrical shocks actually improves your ability not to die from them!

Although this view seems to go against electrical theory, perhaps others who have worked (like me) in the electronics/electrical sector, and who have received many shocks over the years, can give their own view on this.

I am always careful, but do get the odd 220 volt AC shock now and again. I just brush it off (even when I got a shock whilst standing in bare feet in a wet shower!!)

Alternating current is certainly a better choice than being 'glued' to the live wire with a high DC voltage...

Simon

[Gerontion]

When repainting a house I was renting some years ago in Thailand, I regularly received electric shocks off the wet walls. Took me a while to work it out - the first few times it happened I thought I had a trapped nerve; the thought the walls themselves might be live was so bizarre that it me ages to think of it.

[Jdietz]

I have often wondered whether 'getting used' to electrical shocks actually improves your ability not to die from them!

Well I guess you develop dry hands or thicker skin after a while which increases the resistance. I had a very experienced (or just old and stupid but he knew what he was doing) electrician visit me a long time ago who actually had to wet his fingers, otherwise he couldn't even feel if the line was life or not (240V 50Hz).

[PeaceBlondie]

I had a four room beach bungalow rewired on the southern coast of Mexico in year 2000. Upgraded to new service entrance, lots of fluorescent lights in the rafters beneath the bamboo thatch roof, lots of outlets and switches, etc. I pre-positioned the fluor. fixtures in the rafters and ran too much plastic two-wire conduit back and forth. The fixtures had an extra wire which the Mexican technicians did not understand. Four of them argued back and forth for 33 minutes in Spanish. The older guy was a marine boat electrician who was half blind. He tested for live wires by touching them with his hand. We went from one 60 watt bulb hanging from the ceiling about ten feet off the floor, to about 20 feet of fluorescents. And there was light!

[Crossy]

Years ago when I worked for the MOD(N) one of the maintenance men was modifying some power trunking. Part of his mod required drilling a 10mm hole in the steel trunking. He carefully spread the nice fat 440V 3-phase wires (inside the trunking) apart so his drill wouldn't hit them and off he went. Some minutes later there was a VERY large bang and the lights went out followed by some extremely strong language. The wires had drifted back into their original position under the vibration of the drill and the inevitable had happened. It blew the end off the 10mm drill.

[Rimmer]

Years ago when I worked for the MOD(N) one of the maintenance men was modifying some power trunking. Part of his mod required drilling a 10mm hole in the steel trunking. He carefully spread the nice fat 440V 3-phase wires (inside the trunking) apart so his drill wouldn't hit them and off he went. Some minutes later there was a VERY large bang and the lights went out followed by some extremely strong language. The wires had drifted back into their original position under the vibration of the drill and the inevitable had happened. It blew the end off the 10mm drill.

Reminds me of the old mnemonic SIDE which he obviously forgot.

Switch off

Isolate

Dump

Earth

[BillyBobThai]

This is exactely what I was looking for. Anybody who has worked around electricity for a number of years, probably has many stories to tell.

Once as I was talking to 2 friends, I was disconecting a 6 volt battery from the charger. I failed to turn off the charger first. I grabbed the positive and the negative in my left and right hands. After I had pulled them loose from the battery, the charger went to full open circuit voltage, about 400 volt DC. I could not let go of the two clamps, and my friends were sitting there in a fit of laughter. One of them finally said, throw them down. I don't know why, but high voltage DC will not let you just let go.

Probably the most spectacular event was when a 120 volt battery whith a loose connector, flashed. At 5,000 amp, there was a very bright and loud pop.

Robert

[tj916]

I used to own a truck a few years ago with 24 volt electrics. I had a few starting problems so took it to the now defunct Lucas UK.

They fitted an alternator with a defective regulator/rectifier. After a couple of days the truck wouldnt start so I asked my mate to give me a jump.

Unfortunately, his truck was the opposite earth to mine so when I turned the ignition a spark occured in my batteries and blew them to smithereens.

My mate was standing about 2 metres away and was covered in battery acid,luckily it missed his eyes and face.

Bits of the batteries could be found 10 metres away.

Took it back to Lucas and they discovered the faulty alternator and had to replace the tachograph, fuseboard,batteries and every bulb on the truck.

I dont mess with anything electrical anymore.

[PhilHarries]

I have a little yarn about wild, not domesticated, electrics.

I used to belong to the Surrey & Hants canal society restoring the Basingsoke canal in the UK. Back in summer '76, the real long hot one that seemed to last forever, I was working clearing out a lock chamber that was under a road bridge. There was aguide rail alongside the chamber made from railway rails and we had a scaffold winch tower up to road level for hauling materials up and down. Well one particular day that summer did break and we had a humungous thunder storm that passed right overhead so we sheltered under the bridge. I was casually leaning against the guard rail when BANG we took a lightning strike direct on the scaffold tower. The charge ran down the tower and some of it at least came along the rail through me and jumped some three feet and flattened one of the other guys.

I survived (no get away we thought it was your phii writing this) with a better understanding of practical electrics

Warning message #1 : Do not stand within 20 feet of metal structures during an electrical storm.

BBT, I was told during my City & Guilds electrical theory and practice is that the reason DC won't let you release your grip is that the current contracts the muscles and keeps them there. AC on the other hand contracts the muscles briefly until the current changes polarity then you let go.

[jtp]

Hotel in Phuket(No names).........

[Crossy]

A demonstration of how attitudes to electricity have changed over the years.

Some years ago whilst clearing out some old filing cabinets in my MOD(N) office we came across a Royal Navy Test Instruction. it was undated but was obviously c.1915.

It went a bit like this:-

Instructions for Testing the Electrical Firing Mechanism for 12" Naval Guns.

1. Select a reliable Rating (that's the lowest form of naval life next to the rats).
   
2. Send the Rating to the turret with instructions to grasp the gun firing pin.
   
3. Press the 'fire' button.
   
4. Await the Ratings report.
   

These old guns were fired by a 120V DC supply, I wonder how many 'OK' reports were less than accurate (you could use up Ratings at a worrying rate)

EDIT Check out these wonderful old toasters http://www.toastercentral.com/toaster20s.htm

Edited February 23, 2009 by Crossy

[Tywais]

While doing a walk through of our new building checking the electrics came across this that a worker set up, the universal power cord.

Our facility has some substantial opportunities to get into trouble quick. The entrance to the microwave power room for the particle accelerator I manage. No one is allowed in or power up without going through training by me. Also, standing order of two persons in the area when working on the system whether the system is live or not. The charging capacitors can reach as high as 30kV and are discharged at several hundred amps through a Thyratron. A discharge grounding rod is one requirement to discharge the caps before working on the system. Even with the system powered off, the energy in the caps is high. Humidity has to be controlled and less then 55% or component arc over can occur.

One of our systems operates at 450kV and another at 2 Megavolts. Been a few years since being zapped, but the last time was memorable, 20kV power supply with a cap still charged but not for long as my hand made a nice short across it.