poobah said:
Poobah,
Great story. Thanx for sharing it with us. I am glad no-one was injured or killed. I know exactly what you are speaking of having seen it and fought it while dealing with un-iversity types and electrical inspectors. In the case of electrical inspectors a practical working knowledge of electrical behaviour does not seem to be a job requirement, whereas being able to distinguish the color of a dielectric, something electrons are blind to, is.
Hey RCA,
It is entirely likely that someone here will reckognize that whole affair... it was moderately famous for some time. I'll bet one of those white-coats would love toretort to all this; but they can't (shouldn't)... say where or who it was all about. Probably a silver speaker wire guy...
There are two more stories from that installation... if a relevant thread comes up you'll hear those as well!
😉
It is entirely likely that someone here will reckognize that whole affair... it was moderately famous for some time. I'll bet one of those white-coats would love toretort to all this; but they can't (shouldn't)... say where or who it was all about. Probably a silver speaker wire guy...
There are two more stories from that installation... if a relevant thread comes up you'll hear those as well!
😉
In 1967 through 1970 I went to a technical high school that was built in 1960 with stuff that was donated by the Army because it was too old for them. Lots of tube stuff to play with. All of the workbenches were metal, Army green grounded metal. Like most high school kids I beleived that I was invincible, and payed no attention to safety.
We played with Tesla coils, Jacobs Ladders, and all manner of tube equipment on those grounded metal benches. I, and many of my classmates, got the **** shocked out of us many times. There were several trips to the hospital. I got several stitches in my arm as a result of those grounded metal benches. The Army issue instructor told us about these "isolation transformer" thingies that would really help us out, but the school board did not have the budget to buy them.
Each bench had a 20 amp fuse in the panel (circuit breakers were not available yet). Every time you put a hot chassis TV or radio down on the bench there was fireworks, and a blown fuse. They always seemed to have budget for fuses.
It took several years of working for a large electronics company to begin to understand electrical safety. In the 33 years that I have worked there the attitude toward electrical safety has changed from casual awareness to a rules based protocol. Electrical accidents have dissapeared.
I and many of my friends have witnessed or been part of enough near misses to realize that any one of these mishaps could have taken one of us out.
When I moved into this house 28 years ago, I built a lab. At the time I worked on digital and low voltage electronics. I didn't pay much attention to how the lab was set up. There was an incident where I was working on a computer power supply that involved an exploding capacitor with a two foot long flame shooting out of it. In a brief instant I realized that I had no way to shut it off! I had to run out of the room, and shut off the circuit breaker, I didn't even know which one! Sherri was terrified.
Yeah, now it is funny, but it wasn't then. This was about the same time that I started playing with tubes again. I realized that I needed to make some changes to my work area. I have documented these on my web site in the safety page, but the highlights are:
1) Install a master kill switch on your workbench. It can be a simple power strip. It should be mounted where it can be reached by anyone nearby. Make sure everyone in your house knows where it is and how to kill power.
2) Eliminate all accidental paths for current flow that you can touch. This means having no grounded objects within reach of a live circuit. This includes soldering irons and old metal cased test equipment. Bare concrete floors can be a serious shock hazard.
3) Don't play with electricity if you are the only person at home. How can you call for help if a situation arises. Often you are seriously dazed from a non fatal shock, and heart problems can occur later.
4) Even if you have a messy work area, clean up the area surrounding any experiment where live electricity is present.
5) Adopt a strategy where you only work on equipment when it is un - powered. I will attach multiple digital meters to a new amplifier design. That way I can see what is going on inside a new circuit from a safe distance away. I keep my hand on the kill switch when powering up, that way I can kill power instantly. I will use one hand to adjust bias while reading the meters, I do not like to go poking into a live circuit with a meter. You can get a digital meter fro $5 today, get several. Hook them all up, stand back and power up. When I first powered up the 833A amp I had a 1/4 inch Lexan shield and 6 feet of distance between me and the amp. Fortunately it was not needed, but it remained for most of the testing. You must realize that ONE slip up can FRY you.
We played with Tesla coils, Jacobs Ladders, and all manner of tube equipment on those grounded metal benches. I, and many of my classmates, got the **** shocked out of us many times. There were several trips to the hospital. I got several stitches in my arm as a result of those grounded metal benches. The Army issue instructor told us about these "isolation transformer" thingies that would really help us out, but the school board did not have the budget to buy them.
Each bench had a 20 amp fuse in the panel (circuit breakers were not available yet). Every time you put a hot chassis TV or radio down on the bench there was fireworks, and a blown fuse. They always seemed to have budget for fuses.
It took several years of working for a large electronics company to begin to understand electrical safety. In the 33 years that I have worked there the attitude toward electrical safety has changed from casual awareness to a rules based protocol. Electrical accidents have dissapeared.
I and many of my friends have witnessed or been part of enough near misses to realize that any one of these mishaps could have taken one of us out.
When I moved into this house 28 years ago, I built a lab. At the time I worked on digital and low voltage electronics. I didn't pay much attention to how the lab was set up. There was an incident where I was working on a computer power supply that involved an exploding capacitor with a two foot long flame shooting out of it. In a brief instant I realized that I had no way to shut it off! I had to run out of the room, and shut off the circuit breaker, I didn't even know which one! Sherri was terrified.
Yeah, now it is funny, but it wasn't then. This was about the same time that I started playing with tubes again. I realized that I needed to make some changes to my work area. I have documented these on my web site in the safety page, but the highlights are:
1) Install a master kill switch on your workbench. It can be a simple power strip. It should be mounted where it can be reached by anyone nearby. Make sure everyone in your house knows where it is and how to kill power.
2) Eliminate all accidental paths for current flow that you can touch. This means having no grounded objects within reach of a live circuit. This includes soldering irons and old metal cased test equipment. Bare concrete floors can be a serious shock hazard.
3) Don't play with electricity if you are the only person at home. How can you call for help if a situation arises. Often you are seriously dazed from a non fatal shock, and heart problems can occur later.
4) Even if you have a messy work area, clean up the area surrounding any experiment where live electricity is present.
5) Adopt a strategy where you only work on equipment when it is un - powered. I will attach multiple digital meters to a new amplifier design. That way I can see what is going on inside a new circuit from a safe distance away. I keep my hand on the kill switch when powering up, that way I can kill power instantly. I will use one hand to adjust bias while reading the meters, I do not like to go poking into a live circuit with a meter. You can get a digital meter fro $5 today, get several. Hook them all up, stand back and power up. When I first powered up the 833A amp I had a 1/4 inch Lexan shield and 6 feet of distance between me and the amp. Fortunately it was not needed, but it remained for most of the testing. You must realize that ONE slip up can FRY you.
Hey poobah,
Once I had a technician that didn't pay close attention to things around him. Safety in particular.
When he left (for a job at a UPS company) I warned him again. Well, a couple months into his new job, he shorted "the battery room". He allowed the main positive from the room to touch the negative.
His words "the buss bars instantly wielded together" (no breaker!). He ran out of the room and by the time he reached the outside door, the smoke was coming down from the ceiling (plant height guys). He shut the factory down for a day but at least he didn't kill anyone. As punishment, his job was to replace all the batteries (lead acid) by hand. He actually told me this later and admitted that I was right, but that he had (finally) learned his lesson.
That was about 15 years ago, and he still lives. He has much more respect for voltage, current and batteries. Your story reminded me, and I got a horrified laugh out of it.
-Chris
Once I had a technician that didn't pay close attention to things around him. Safety in particular.
When he left (for a job at a UPS company) I warned him again. Well, a couple months into his new job, he shorted "the battery room". He allowed the main positive from the room to touch the negative.
His words "the buss bars instantly wielded together" (no breaker!). He ran out of the room and by the time he reached the outside door, the smoke was coming down from the ceiling (plant height guys). He shut the factory down for a day but at least he didn't kill anyone. As punishment, his job was to replace all the batteries (lead acid) by hand. He actually told me this later and admitted that I was right, but that he had (finally) learned his lesson.
That was about 15 years ago, and he still lives. He has much more respect for voltage, current and batteries. Your story reminded me, and I got a horrified laugh out of it.
-Chris
Hey Chris,
Good that he learned his lesson the "easy" way... living. I have seen quite a few battery shunting stunts as it seems I'm always involved with batteries.
Here's another safety tip:
When you buy your new DVM; buy a box of proper replacement fuses... sometimes there are 2 different types. If you're slick, you can wrap one up in heat shrink and hot glue it somewhere inside the meter or just put it in the pouch... you did spend the extra $10 and get the pouch... right???
Why? Sooner or later you will screw up and try to measure a current you shouldn't have... Then you will wrap the old fuse in foil because you don't have a fuse and still have to measure some damn current somewhere.
Then you will forget the jury-rigged the fuse. Then you will go and try to measure some current you shouldn't... again (we all do it). This time though, the test leads turn into red-hot smoking lines of terror. Molten plastic sticks to skin like superglue and takes forever to cool.
I know a guy that after ten years still two nice scars across the top of his forearm, albiet small, from 3rd degree burns.
** DON'T RIG YOUR METERS!
I had this happen so many times that I collected all the meters from everyone, filled the banana socket for current with epoxy, and bought all the guys Hall-effect clamps for measuring currents. These current clamps get cheaper every year; and the fuses are allways expensive as hell anyway... worked out pretty good in the long run...
😉
Good that he learned his lesson the "easy" way... living. I have seen quite a few battery shunting stunts as it seems I'm always involved with batteries.
Here's another safety tip:
When you buy your new DVM; buy a box of proper replacement fuses... sometimes there are 2 different types. If you're slick, you can wrap one up in heat shrink and hot glue it somewhere inside the meter or just put it in the pouch... you did spend the extra $10 and get the pouch... right???
Why? Sooner or later you will screw up and try to measure a current you shouldn't have... Then you will wrap the old fuse in foil because you don't have a fuse and still have to measure some damn current somewhere.
Then you will forget the jury-rigged the fuse. Then you will go and try to measure some current you shouldn't... again (we all do it). This time though, the test leads turn into red-hot smoking lines of terror. Molten plastic sticks to skin like superglue and takes forever to cool.
I know a guy that after ten years still two nice scars across the top of his forearm, albiet small, from 3rd degree burns.
** DON'T RIG YOUR METERS!
I had this happen so many times that I collected all the meters from everyone, filled the banana socket for current with epoxy, and bought all the guys Hall-effect clamps for measuring currents. These current clamps get cheaper every year; and the fuses are allways expensive as hell anyway... worked out pretty good in the long run...
😉
poobah
You probably don't bother getting probes with you meter because you guys in Arizona used dried rattlesnakes instead.
They let you know when you get a live one.
You probably don't bother getting probes with you meter because you guys in Arizona used dried rattlesnakes instead.
They let you know when you get a live one.
Poobah, Joe,
LOL
We just have to get together some day! You guys are good at cracking me up. 😉
-Chris
LOL
We just have to get together some day! You guys are good at cracking me up. 😉
-Chris
Quote:
These current clamps get cheaper every year; and the fuses are allways expensive as hell anyway... worked out pretty good in the long run...
I can bring a new meaning to the word cheap.
I'll make some good old corn cobs into current clamps for ya.
These current clamps get cheaper every year; and the fuses are allways expensive as hell anyway... worked out pretty good in the long run...
I can bring a new meaning to the word cheap.
I'll make some good old corn cobs into current clamps for ya.
Joe, Chris,
How far is it from Georgetown to Corn land? One of my biggest clients/projects is in Des Moines and I'm to be heading there one of these days.
I think it would be fun to just drink beer (assuming Chris ain't allergic to it) and rummage through the Bridge basement.
😉
How far is it from Georgetown to Corn land? One of my biggest clients/projects is in Des Moines and I'm to be heading there one of these days.
I think it would be fun to just drink beer (assuming Chris ain't allergic to it) and rummage through the Bridge basement.
😉
I think you will have to wait until about August for the snow to thaw in Georgetown. Chis gets snow bound in about October and doesn't get dug out again until August.
Sounds like a good time😀
Sounds like a good time😀
Hi Guys,
It'll be a while. Joe's right. I am snow bound a bit. I'll bet he wants be to stay in the basement for a few months yet to do some work.
Beer is great stuff. Dark and strong. Hmmm, you fellas may have to cross the border to get the headier stuff unless they serve full bore imported there.
Corn? Heck, I'm surrounded by corn. I get a buzz of corn starch (that's the really good allergy). My 20 is north west of Toronto, the big smoke. If I get a training course down there I'll let you know. Once my life is back on track I'll be able to travel some more.
You are welcome in the basement any time fellas. I just can't carry it with me. They may have a problem figuring it out at the border. 😀
One day guys, we just have to hook up somewhere!
-Chris
It'll be a while. Joe's right. I am snow bound a bit. I'll bet he wants be to stay in the basement for a few months yet to do some work.
Beer is great stuff. Dark and strong. Hmmm, you fellas may have to cross the border to get the headier stuff unless they serve full bore imported there.
Corn? Heck, I'm surrounded by corn. I get a buzz of corn starch (that's the really good allergy). My 20 is north west of Toronto, the big smoke. If I get a training course down there I'll let you know. Once my life is back on track I'll be able to travel some more.
You are welcome in the basement any time fellas. I just can't carry it with me. They may have a problem figuring it out at the border. 😀
One day guys, we just have to hook up somewhere!
-Chris
Poobah, when did you move to AZ? I thought you were in the Pacific NW. Easier for a sasquatch to blend in in Oregon. I was attaching new equipment to the massive copper 48 and 130 volt busses in a telco/telex exchange years back as part of my job as an installer. I was especially careful and nervous working on those hot connections. The 48 volts from the battery room was fused at 1200 amps. That would have been a 60 kW spark if I had accidentally touched the crescent wrench to ground. Did anyone mention not to wear a wristwatch or finger jewelry? I never have had the habit.
Chris, I am really slow this weekend. You said you had a accident prone tech that went off to work for UPS. It didn't make any sense to me why he would be working around a "battery room" for a company that smashes parcels. This morning while making my coffee a light went on. 😀
Talk about them getting a bit confused at the border when you try to cross with your basement! I had all my technical gear, I mean all of it, literally my entire basement and some in a 45 foot highway trailer en route to the BigEar radio telescope of the late John Kraus of Ohio State U and was trying to cross from Ontario into the US back in the early 90's with it. They not only would not let it in, they siezed it! I got it back but it never did get into the excited states.
Since my QTH is not far from Chris' NW of TO can I get in on this get together that likely won't happen? Thinking about it will make me feel warm and give me a fine sense of comaraderie at no cost or trouble. 😉
Chris, I am really slow this weekend. You said you had a accident prone tech that went off to work for UPS. It didn't make any sense to me why he would be working around a "battery room" for a company that smashes parcels. This morning while making my coffee a light went on. 😀
Talk about them getting a bit confused at the border when you try to cross with your basement! I had all my technical gear, I mean all of it, literally my entire basement and some in a 45 foot highway trailer en route to the BigEar radio telescope of the late John Kraus of Ohio State U and was trying to cross from Ontario into the US back in the early 90's with it. They not only would not let it in, they siezed it! I got it back but it never did get into the excited states.
Since my QTH is not far from Chris' NW of TO can I get in on this get together that likely won't happen? Thinking about it will make me feel warm and give me a fine sense of comaraderie at no cost or trouble. 😉
Hi Rob,
Ooops 🙂devilr: ) has no idea what they are doing, never mind wires!
At least you got your basement back! Did they try to charge you duty on the way back in? 😉
If these "characters" 😎 come up you are more than welcome by as far as I'm concerned. I need to "pop" by your place sometime. I don't have any excuse not to do that when things thaw out a bit. I am hoping to get around myself if I get the chance. If I can get down there by taking a training course, so much the better.
A west-end TO meet would be nifty.
-Chris
Ooops 🙂devilr: ) has no idea what they are doing, never mind wires!
At least you got your basement back! Did they try to charge you duty on the way back in? 😉
If these "characters" 😎 come up you are more than welcome by as far as I'm concerned. I need to "pop" by your place sometime. I don't have any excuse not to do that when things thaw out a bit. I am hoping to get around myself if I get the chance. If I can get down there by taking a training course, so much the better.
A west-end TO meet would be nifty.
-Chris
anatech said:
Getting my basement back cost me money but not from the Canadian idiots.
You are welcome to drop by anytime. Yes a meet out this way would be fun.
Originally posted by ilimzn
What height of fall won't kill me?
```````````````````````````````````
i've heard that a ww2 bomber crewman jumped
from a burning plane at 18,000 feet/no parachute
"the last thing i remember was seeing the stars"
something about trees breaking the fall,
and quite a few bones.
What height of fall won't kill me?
```````````````````````````````````
i've heard that a ww2 bomber crewman jumped
from a burning plane at 18,000 feet/no parachute
"the last thing i remember was seeing the stars"
something about trees breaking the fall,
and quite a few bones.
Me thinks a bunch of Canadians getting bombed in a basement kills everything within a ten mile radius.
Since this thread as turned into a story book here is a couple of examples where engineers should of known better.
About 30 years ago I worked for a company who produced photo diodes along with cathode ray tubes, anyway we had a new vacuum deposition unit installed, little did I know the engineer had a faulty vacuum switch. So he decided to bypass the switch just to get out and home. Being a new system I did a process called plasma cleaning, basically the system goes under vacuum then a tiny amount of argon is introduced inside the vacuum jar were 2 electrodes that as approximately 3000V @ 75mA applied (one of the best blue glows in the business). I shut of the argon but forgot about the HT only when the vacuum was let down I noticed a blue orange tint reappear. That switch should of shut off the supply but it could have been a lot worse had a operator been inside the jar with the HT on. The same company had many incidents with toxic gas leaks acid spills, and room that froze solid and remained like that for over a week due to as liquid nitrogen valve sticking open. Strange the company went on to add boron 11 to it’s list that was used in the Three Mile Island mop up.
Up to date I work in the cable industry early one morning we had a 20kvA UPS installed all of the ordering and requirements were taken out of our hands by the facilities manager, well I had some doubts about the capacity of this UPS but it was only suppose to run for the few minutes the generator took to spin up.What I was not aware of it had been wired to feed the whole building not just the CATV headend and no one thought of the power factor they just measured current with clamp meters . About an hour after the electrician left a huge bang came from down stairs, I found the UPS having a C***P the isolation switch was behind the UPS. No way was I going into that room with the fireworks taking place I let the Halon do it’s thing.
With incidents like these I never assume and take my safety for granted especially by others.
About 30 years ago I worked for a company who produced photo diodes along with cathode ray tubes, anyway we had a new vacuum deposition unit installed, little did I know the engineer had a faulty vacuum switch. So he decided to bypass the switch just to get out and home. Being a new system I did a process called plasma cleaning, basically the system goes under vacuum then a tiny amount of argon is introduced inside the vacuum jar were 2 electrodes that as approximately 3000V @ 75mA applied (one of the best blue glows in the business). I shut of the argon but forgot about the HT only when the vacuum was let down I noticed a blue orange tint reappear. That switch should of shut off the supply but it could have been a lot worse had a operator been inside the jar with the HT on. The same company had many incidents with toxic gas leaks acid spills, and room that froze solid and remained like that for over a week due to as liquid nitrogen valve sticking open. Strange the company went on to add boron 11 to it’s list that was used in the Three Mile Island mop up.
Up to date I work in the cable industry early one morning we had a 20kvA UPS installed all of the ordering and requirements were taken out of our hands by the facilities manager, well I had some doubts about the capacity of this UPS but it was only suppose to run for the few minutes the generator took to spin up.What I was not aware of it had been wired to feed the whole building not just the CATV headend and no one thought of the power factor they just measured current with clamp meters . About an hour after the electrician left a huge bang came from down stairs, I found the UPS having a C***P the isolation switch was behind the UPS. No way was I going into that room with the fireworks taking place I let the Halon do it’s thing.
With incidents like these I never assume and take my safety for granted especially by others.
Hi Jacco,
Depends on the type of beer we're drinking.
Hey Pete,
So true! I refuse to trust anyone with my safety these days in a plant setting.
-Chris
Depends on the type of beer we're drinking.
Hey Pete,
So true! I refuse to trust anyone with my safety these days in a plant setting.
-Chris
tomtt said:
Just goes to show you, if you flap your arms fast enough, lightning won't hit you
*HIC*If it goes through your left hand to some other part of your body, it will probably pass through your heart. It is all about how you do it. Never lose respect for it...
Using alligator clips and only my right hand for measurements (this is approved practise), I have been hit by 1000v from one finger on my right hand to another finger on my right hand. All I did was spill my coffee.
Using both hands, I have been knocked hard by only 100v.
Using alligator clips and only my right hand for measurements (this is approved practise), I have been hit by 1000v from one finger on my right hand to another finger on my right hand. All I did was spill my coffee.
Using both hands, I have been knocked hard by only 100v.
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