900 volts, 1 finger ,and a trip to the emergency room

[W1IA]

WOW! Glad you are ok G.....

Brent W1IA

[AJ1G]

Boy Gary - that was a scary one...glad you are OK. First time I've heard of someone getting a MI from a bite like you did (that lived to tell about it).

Worst bite I ever got was from one of those old working model toy one lunger steam engines.  As a young kid of 12 or so (pre ham radio days) I somehow came into possession of one of them .  This particular model engine had a 120 V electric heating element in the boiler section.  It had one of those two pin connectors and matching two wire appliance cords that you used to see on electric frying pans.  One day, while I was BAREFOOT, in wet swim trunks, having just gone for a swim in the neighbors pool, I decided to play abound with this thing on our back stoop.  To provide power, I took out the bulb from the porch light, screwed in one of those light socket outlet adapters and plugged in a 2 wire extension cord. I then plugged the cord from the steam engine in. There I was, standing on the ground, barefoot, and  when I grabbed the boiler to pick it up and move it, my entire body felt like one big AC powered shaker!  When I yelled my voice had AC modulation on it! My hand froze around the cylindrical boiler and I could literally not let it go.  Luckily my brother (also barefoot and in wet swim trunks) was with me and he  was able to knock it free (he got a brief bite in the process as well), so I am still here to tell you about it.  Apparently the heating element had developed an internal short to the boiler.  Pretty scarily designed toy in retrospect.

[WA1GFZ]

So Gary think about the last thing you remember and the first thing you remember when you came to. You will enjoy think about it in the future.
I worked in a garage when I was a kid and had a tire explode on a change machine as I was setting the bead. It took me off my feet and I landed standing up next to the time clock where we had a newspaper article of a guy and his son killed inflating a tractor tire. Everyone watching told me said the first thing I did was grin from ear to ear because I looked at the picture and knew I was still present.
I couldn't hear for a while and had the shakes for a couple hours. After that everytime I set a bead on a tire the pop would make me jump.....Me friends at work had a lot of fun with my new found fear. I saw the big long tunnel that time.......but the light was far away

[WB2EMS]

Wow Gary, that sounds like it was *too* close. Glad to hear you're mending well but  the MI is scary.

I joined the club in about 1970, while working on that 75 watter from the '64 handbook, the one with the 1625 under the chassis. I was having problems getting output into my light bulb dummy load and was troubleshooting it on it's back, balanced on the transformer at the back of the chassis. It wouldn't balance, so I had to hold the chassis to steady it with my left hand. I was powering it up right side up, then shutting it down with the key closed to hasten the draw down of the capacitors in the HV supply and flipping it over to check things and make measurements.

The last time I shut it off but forgot to key it as I was doing it, then flipped it over on it's back and reached inside to poke the parasitic suppressor on the plate cap. The caps still had substantial charge in them and I was getting it from one hand to the other. I didn't realize what was happening. My buddy Ken was in the room with me and as I started shuddering with my arms spasming I thought Ken was playing a joke on me, having grabbed me by the arms and shaking me violently. When the caps ran down or I finally shook myself free I spun around and started yelling at him to "cut it out!", only to find he was across the room from me. Then it dawned on me what had happened and it scared the crap out of me! Other than being shook up and having sore arms for a couple of days, no real problem. As others mentioned, being young (and dumb) helped.

The previous best effort was at age 7, back when I was first learning about batteries and light bulbs and stuff in cub scouts. I had run down all my D cells playing one afternoon. That year they were advertising battery rechargers on the TV, showing them plugging into the wall and then recharging various batteries. I had the cut off plug from a string of defunct Christmas series lights, so my young brain decided that if I connected my dead battery across that plug and plugged it in it would recharge. So I did that. Fortunately I couldn't manage to hold one wire with each hand on the cell and still manage to plug it in. So I transferred it to one hand holding both ends of the battery, and plugged it in with the other! ZORCH!! Knocked me on my ass. And left me buzzing, probably from the adrenaline dump. I was shaking and chattering and thought I had electricity loose in me causing that, so I went to the kitchen and got a glass or three of water to "short it out" inside me and it seemed to work. My mom hollered up the hall to "ask what that noise was". Like legions of other young experimenters, the answer was "Nothing!"   

Someone mentioned a little ditty to remind themselves to be careful. Excellent idea. When I work on my homebuilt airplane, sometimes I'm racing to put things together and get a quick flight in before the sun goes down. Or I want to rush through the preflight inspection and get flying. I bring up the image to mind of a lonely tombstone with the words "He was in a hurry" on it as my old instructor said to do. Works every time.
 

[John K5PRO]

I've been very lucky I think, worst has been a few brushes with 120 VAC as a kid, with AC/DC hot chassis radios and ground. And a few Tesla coil bites for fun. I am knocking on wood as I speak, because I deal with some serious HV at work these days, our power supplies are -85 kV 25 amps for one type, 30 kV DC 25 Amps on another type of rig, and 15 kV at 2 Amps on another. They are engineered to be used safely, as we have strict written procedures, red lock out, grounding policies, two-man rules  when putting the sticks across the capacitors, annual CPR training, annual capacitor shorting training, now we have an AED beside each capacitor vault.

I saw a friend almost meet his maker, when we were testing a new 3500 watt FM rig, at Broadcast Electronics, 25 years ago. I was the high power engineer for the transmitter, and he designed low level stuff, like the power control logic, the stereo generator, stuff up to 28 VDC or so. It was customary to test prototypes with the back off, to make quick changes, measure stuff, adjust the neutralization easily, etc. So here it was, pumping out 3.5 kW into a load, when he walked in from his lab, to show me something he was curious about. Before I could yell stop, he reached in the back to touch the little motor that ran a variac on the screen supply, for VSWR foldback system. Right next to this motor, was exposed 4100 VDC. Being a prototype, things weren't guarded under plastic or in their final production layout. He hit it, and his other arm was resting on the rack. He flew across the floor, and the 30 Amp 220 VAC breaker tripped on the rig. It all happened really fast. In less than a minute, he started getting up, a bit groggy, with a black mark on his finger and on the opposite elbow. His arm and finger turned colors, but he refused hospital visit, and of course, the management was pretty upset at us.

[W1RC]

I formly believe that then you're number is up..........it's up!

We are all very thankful that this time wasn't it.  See you at Deefield!

73,

MisterMike, W1RC

[Ed/KB1HYS]

Gary,

Glad you're ok OM.  It would be a damn shame to loose that "ON the AIR" presence.  
I've been bitten a few times myself, but the worst case I saw was a tech who had gotten across a 400V/16amp pulsed circuit in a testing facility.  I guess he figured he could make adjustments between pulses?? or just forgot to de-energize the circuit.   Launched him across the room, off the -wall and stopped his ticker.  The fellow with me de-energized the place by yanking cables out of the boxes on the walls. (We didn't know what he was working on and what had gotten him at the time and he was laying across a real JS rats nest of cables and such). Did CPR on him until the Paramedics showed up.  He lived. wasn't quiet the same though...
Makes me pretty careful around the HV stuff.

[n2bc]

Gary, glad you are OK!

I'll add two quick related stories - along with my personal motto:  A shorting stick is your best friend & never trust the bleeders or the HV meter!

I had picked up a 2KW plasma generator on a dumpster dive.  Hooked it up for testing prior to reworking it, no HV indication.  Turned it off & started poking around, took 4KV from the filter cap across my hand.  At least I was smart enuf to only have one hand stuck in there. There was no HV indication because the metering was off the bottom of the open bleeder.  

Just a couple months ago my Harris amp started acting wierd. I noticed the HV seemed high.  Turned it off and the HV hung in there for a really long time - duh.... here we go again. This time there were TWO 100W paralleled bleeders that were both open.

I have an earlier one that involves a shorting interlock, exploding panel meter, getting knocked out of my chair, big knot on my forehead and a broken nose... But I obviosly didn't learn much from that one.  Pretty lucky tho.

Be careful!   73, Bill   N2BC

[N2udf]

Gary,
So glad to hear you are OK.I had a similar experience with a Valliant(albeit certainly not as serious)I was tired and should have gone to bed,But,just that one last thing.All it cost me was a burned finger,and a new pair of shorts.Best to you...Lee N2UDF.

[WB2CAU]

Gary, I'm thankful that you survived and are ready to continue.  There are some who just take up a new hobby after a close call like that.

My HV experience occurred in 1965 (when I was 15) with the home built power supply for my first homebrew tube transmitter, a pirate transmitter for the AM broadcast band (gee, I hope the Statute of Limitations have past).  I was careless and took about 500V DC (hand to hand) from that supply.  It was like getting hit with a baseball bat and knocked me off my chair in my bedroom. Fortunately, it was a life's lesson and it made me a whole lot more cautious when working with HV, both in hobby and career.

These close calls certainly earn us respect for the voltages we play with.

Despite the hazards, our group (as AMers) have relatively few fatalities.  The only fatality I recall within the AM group over the years was Ralph, W2WME. 

Eric - WB2CAU

[N3DRB The Derb]

put "safety bleeders" on all yer 100 w bleeder rx's in the form of 1~2 megohm 2 2 watters  in parallel rx's  to hot side to ground. It will discharge them if he big ones open up...slowly, but by the time you get the case off they should be OK.

[Vortex Joe - N3IBX]

Gary,
       Thank God you're alright and are able to tell us what happened. The alternative isn't very pretty.
       I hope you're feeling a bit better each day. It's never something that anyone expects to happen to them and always someone else.

Best Regards and Good Health!
                                         Joe Cro N3IBX

[W3GMS]

Gary,
Your experience is a good reminder to all of us.  We sometimes get complacent and stuff happens.  
When I was 15 I was working on my home brew 811 modulator power supply.  I had turned off the power on the 1500W supply and trusted the wire wound bleeder.  That was a big mistake.  I went into the power supply to add an extra oil filled cap and that is the last thing I remember. I pulled the 6 ft rack over and was half out my bedroom window so they tell me.  When I woke up I was on the couch as the EMT’s were working on me....The second time happened a bit latter which I was working on an old timers amp at his QTH.  He put the bleeder for the ps in the amplifier rather than on the ps chassis!  I unplugged the cable between the amp and ps and assumed the bleeder was still doing its job...another big mistake.  It nailed my real good but I survived that one as well.  A shorting stick is now part of my tool kit when working on anything that has HV in it...
In both cases, when I recovered I got right back on the project...

Eric, I do remember Ralph W2WME electrocution several years ago.  I believe he was working on an SB-220 linear at the time.  What a tragedy...
joe GMS        

[W3RSW]

Well, it's pretty obvious that just about every ham that's active on this board has been bitten by HV at the worst and 110 to 120 AC at the least.  Many of the experiences have the same common denominator.  Capacitors carry a charge almost indefinitely (for our purposes) until discharged.  Capacitors can discharge far more current "instantaneously" than the supply can normally.  In about half of our cases we can be thankful that the supply was "off" and that the voltage died exponentially.  

Statistically our shocking experiences present an alarming prognosis.

And the amazing thing is that in all our cases our experiences weren't fatal. By definition those on the board are alive.... as dumb but very logical as that sounds, let's keep it that way!

I noticed as the thread matured, responses have gone from alarm to a little humor but in almost every case another personal story just short of tragedy was added.

I think releasing all our stories has been cathartic; we surely need to relate these experiences in the aggregate and we surely aren't going to remember each and every instance but we will think Safety First.

So once again Gary, OM, I'm glad you related your saga.  Many of us probably would have yelled "Nothing" to Ma as did one of our cohorts just like most of us  many years ago.....    been too embarassed and so forth.

Perhaps you'd like to create another section on "Safety" or at the least a sub-topic in the technical repair/homebrew section.  A copy of this whole thread might be a good start. Include this type of electrical safety as well as antennae into HV lines, mechanical safety, and so forth.

[John K5PRO]

Wow, SB220 eh? That thing has a stick switch, doesn't it, to prevent removing the case while it is running. Of course a clamp will bypass it. I had mine running hot out of the case in the 1990s as I was mod'ing it. So easy to reach in and tweak, so it took a lot of restraint, and not working while tired...

[K1JJ]

This thread may go down as one of the most relevant and interesting in years.  I've found myself reading it a few times.  Some of the stories are great.  G, you might consider making it a "sticky."


Bottom line: The older we get, the more vulnerable we are and less apt to recover.  What we survived when younger may do us in now, especially when it comes to the heart.


Here's some more info about electrocution....

Even though a power supply is capable of big current (1-2 amps) the body will take only as much current as it's resistance calls for, just like a resistor and Ohm's law..

Do this test:  Take your VOM and grab the probes with dry fingers, hand to hand. I measured about 600K myself.  Then wet your fingers with spit (salty solution) and measure again. I saw about 90K.

Some statistics say we need about 18 ma through the chest to cause death by ventricular fibrillation. We can handle more DC than AC current. What sometimes happens in extreme power line cases is the heart gets stimulated so violently that it tears it's own muscles and tendons apart.  Imagine the tiny pulses from the brain pulsing the heart in normal rhythm compared to a huge charge from a HV supply.

Anyway, let's look at the current produced by 1000V at 600K for dry hands....   E/R = 1.6 ma. 

Now wet hands: 1000V at 90K =  11ma.     We're getting there.


How about 2kv?    2000v/90k =  22ma.... we are there.  Sweaty hands/arms/legs/head at 2KV is about what the electric chair used.

** The big problem is that once the top layer of skin is penetrated by the initial zap and we move into soft, salty flesh, the body resistance drops dramatically and the current then surges. This can cause the body fluids to boil and cause explosions in extreme cases in addition to torn muscles, etc..  It's much like a runaway situation when carbon trails are made during arc-overs on other materials. And it all happens in a split second.

There are also certain parts of the body with very low resistance, like behind the ears for instance. Fortunately, the hands have a thick layer of (dead) skin to slow the initial current flow if there is no immediate puncture.

Anyway, this thread has caused me to stop and reflect on safety here in the shack.

I appreciate the stories and heads-up warnings as I'm sure everyone has.

Best of luck and safety -  and keep the stories coming. 

T

[W2INR]

I appreciate all the kind words

It was a simple stupid move on my part. It was after 9:00 at night on Sunday evening.  I had spent the entire weekend replacing all the relays and modding up the Ft 102. I was tired and decided to talk with Bill DUQ and Mr Mike on Skype.  We broke up around 9:00 pm and I decided I wasn't tired and thought I would do some more work on the FT 102.  I was tired and burnt. I must have hit the switch when I flipped the rig over to do a mod on the AF board and I didn't notice it was still plugged in. The rest was just plain stupid.

On recommendations from my doctor I went to see a cardiologists this morning and I got some good news  - --  I think. He said according to the data he received from my visit to the ER room on Sunday that I might have had a mild attack but thinks I had experienced Ventricular fibrillation which can be caused by electrical shock. He did say I was still experiencing arrhythmia from the incident and that could correct itself in time - - time will tell. Other than that I seem to have survived the ordeal and besides the headache/lump on my head, a few sore muscles, and bruised pride  - - I feel OK Fine!!

I really posted this as a reminder to all of us. I have been in this hobby for 20 years and I have been bit 3 times. Each time I can attest that it was totally avoidable had a few brain cells been in operation at the time.

Thanks again to all

G

[W9GT]

Wow! Gary, I'm glad that you're OK!  Seems that most of us have had some "shocking" experiences in our lives at one time or another....glad to be able to live to tell about it.

My experience was with a 3x 4CX250B amplifier that developed a problem with the 2KV power supply.  I somehow got across the B+ and the next thing I knew, I was clear across the room against the wall...wondering what hit me!  In the process of being unceremoniously tossed across the room, I fell or tripped across my tool box which was on the floor and scattered tools far and wide!  Wow, it took me hours to find everything and put the tools back in the box.  It took me even longer to recover from having the stuffins knocked outta me.

A friend of mine almost met his maker, while working on a 4-1000 amp with 6KV on the plate. He somehow pulled the HV wire out of one of those Millen HV connectors while reaching around the back of the chassis and connected it to his hand while it was hot.  Needless to say....the results weren't pretty.  He ended up in the hospital with a big chunk out of his hand and severe burns.  He survived that OK, but then nearly died from a staff infection that he acquired in the hospital!

We all should be reminded to take care and be safe around High Voltages.  Don't take anything for granted when working with the stuff.  It can kill you.

Take care Gary....and may we all learn from your experience and remember to be safe.

73,  Jack, W9GT

[W1UJR]

Just heard about this last night when Brent and some of the fellows were chatting on air.

I'm glad you're OK Gary, that was quite an event, someone must like you up there.

Tom's right, this is a lesson to all of us, should be made sticky.
Just reading the experiences of others gives me a new found appreciation for even the low power rigs I've been playing with.

Hoping that you heal quickly!

[WA1GFZ]

Bottom line you should not be alone or tired when playing with high voltage.
My last mistake took out the 160 PDM modulator 2:00 in the morning when I should have gone to bed. It woke the XYL when the FETs blew due to a stupid mistake.

Come a little bit closer your my kind of man......

[W3FJJ]

Glad you ok Gary, that's scary..

The worst shock I got was with my Valliant. I was using an external 811 modulator
which was getting the B+ off the vaillant through the accessory plug. I forgot to connect the
ground from the valliant to the ground (chassis)of the modulator. I was touching the Modulator chassis
with one hand and flipped the PTT switch on the valliant with the other. I then became ground connection.
between the two. I immediately got thrown back on my butt, saw stars for a second. No damage, but I
never forget that lesson....

Becareful folks...  Chuck

[k4kyv]

He said according to the data he received from my visit to the ER room on Sunday that I might have had a mild attack but thinks I had experienced Ventricular fibrillation which can be caused by electrical shock. He did say I was still experiencing arrhythmia from the incident and that could correct itself in time - - time will tell.

You are indeed fortunate.  That was too close for comfort. Ventricular fibrillation is what usually causes death by electrocution.  Yours must have been a very mild case, because I have always heard that once it starts, it is irreversible without the intervention of a machine called a defibrillator.

From a Wiki article:

Ventricular fibrillation

A low-voltage (110 to 220 V), 50 or 60-Hz AC current travelling through the chest for a fraction of a second may induce ventricular fibrillation at currents as low as 60mA. With DC, 300 to 500 mA is required. If the current has a direct pathway to the heart (e.g., via a cardiac catheter or other kind of electrode), a much lower current of less than 1 mA, (AC or DC) can cause fibrillation. Fibrillations are usually lethal because all the heart muscle cells move independently.

There is a load of information on the web on this subject.  Just do a Google search, typing in <<Ventricular fibrillation, electrocution>>.

I forget his callsign, but sometime in the 80's a well-known AM'er, a W2, got across the HV in an amplifier.  Reportedly, he managed to tell his wife that he had been electrocuted before he lost consciousness.  He didn't survive.  I can still remember the sound of his voice over the air, but can't think of his name or QTH.

[W3LSN]

I forget his callsign, but sometime in the 80's a well-known AM'er, a W2, got across the HV in an amplifier.  Reportedly, he managed to tell his wife that he had been electrocuted before he lost consciousness.  He didn't survive.  I can still remember the sound of his voice over the air, but can't think of his name or QTH.

I think that was Ralph, W2WME.   I remember his voice well. I heard that he met his fate only several years after the fact. I think he had a BC-610.

73, Jim
WA2AJM/3

[Carl WA1KPD]

There are also certain parts of the body with very low resistance, like behind the ears for instance.

Luckily I have a big empty space between my ears that act as an insulator

Seriously, this has been a worthwhile and appropriately sobering thread

Carl /KPD

[W2INR]

I really do not remember anything but pulling my finger out fast and then waking up on the floor. I thought all the damage was done on the finger, it went in one side and came out the other.  When I woke up I felt groggy and knew I hit my head but I just got up and went upstairs grabbed a beer and sat in the den watching TV. It was then that I had noticed the pains in my chest.  Knowing what I had just gone through I just decided to be safe and get checked out.

Go figure, I don't know and it seems to me that the Docs don't really know. How do they tell this stuff from a piece of paper with wiggly lines on it anyway? It had to be a least 2 hours after the event before they took the EKG. Interesting stuff.