Re: [Elecraft] ECOM scare -- FW: Soldering lesson

2017-02-19 Thread Fred Jensen 
Ummm ... I guess it depends on exactly what you do.  I worked for a 
defense contractor for quite awhile, "When you were done with it ... 
shred it."  One young fellow still had his dog tags on the chain around 
his neck.  Fortunately they gagged the shredder before the chain 
strangled him.


73,

Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County

On 2/19/2017 6:00 PM, Bill Frantz wrote:


I have a friend who highly values the symbolism of his wedding ring. 
He is a professional electrician. He wears his ring on a string around 
his neck.


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Re: [Elecraft] ECOM scare -- FW: Soldering lesson

2017-02-19 Thread Bill Frantz 
My wife and I sas w photo of someone who had slipped while 
climbing and wearing a ring which caught. The skin on the finger 
was peeled back like a banana peel. We agreed that no wearing 
our rings in circumstances was more than a good idea. We like 
each other intact.


I have a friend who highly values the symbolism of his wedding 
ring. He is a professional electrician. He wears his ring on a 
string around his neck.


73 Bill AE6JV

On 2/18/17 at 12:37 AM, kl...@acsalaska.net (Edward R Cole) wrote:

My wife gave me a wedding ring and I explained that I would not 
be wearing it to work (2-way radio tech).  She understood.  I 
did wear a watch but removed it when working on live ckts.


---
Bill Frantz| Ham radio contesting is a| Periwinkle
(408)356-8506  | contact sport.   | 16345 
Englewood Ave
www.pwpconsult.com |  - Ken Widelitz K6LA / VY2TT | Los Gatos, 
CA 95032


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Re: [Elecraft] ECOM scare -- FW: Soldering lesson

2017-02-19 Thread Guy Olinger K2AV 
On Sun, Feb 19, 2017 at 3:37 AM, Edward R Cole  wrote:

> One other consideration,if using metal tools around high current sources
> (like batteries or power supplies): Shorting the terminals may cause rapid
> heating and result in explosions.  An exploding lead-acid battery can hit
> you with shrapnel and acid which can burn you, blind you, or cause death!


Back in the way-back when I was a young communications tech (still had
hair) working for AT in Wash DC, the long distance office I worked in had
a 10,000 ampere 12 volt DC supply which supplied entire floors of Western
Electric 310A and 311 vacuum tube filaments, plus other stuff. Was
motor-generators plus floating battery backup. Single cell low gravity lead
acid batteries, about 20x20 inches and 5 feet tall, four strings in
parallel.

The bus bar hook up leading out of the battery room to distribution panels
was four 1 inch thick, 4 inch tall solid bars in parallel for the positive
rail and the same for the negative rail. So the DC conductor was a pair of
"wires" that each had 16 square inches of copper cross section.

It was not insulated, and anyone working in there had to have all metal
jewelry, watches etc removed. Also all tools except for the tip had to be
wrapped in this gunky black cloth tape, two wraps deep. No exceptions, ever.

A contract employee was in there once, and went in there with a large
unwrapped wrench, working over the top of the bus bars. He dropped the
wrench across the plus and minus bars, which were separated by about six
inches, way more than enough to insulate for 12 volts.

Accounts said that there was a flash and both ends of the wrench vanished
into metallic vapor. The center portion dropped through the gap without
ever losing speed and bounced on the concrete floor. It was so hot it
burned leather gloves. The speculation was that the battery line could
easily have supplied a pulse of 30,000 or 40,000 amps. On one occasion I
saw the load ammeter go over 10,000 amps.

Dunno if the idiot that went in there with an unwrapped wrench got canned
or not, and don't know if he suffered eye injuries from the flash. Rumor
was that he immediately left the battery room and exited the building.

The amps that can be supplied by modern lithium batteries are so high that
it can destroy and even explode the battery.

All prior warnings of this sort in these threads are definitely
well-founded and probably understated if anything.

73, and may you never melt down any of *your* wrenches,

Guy K2AV
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Re: [Elecraft] ECOM scare -- FW: Soldering lesson

2017-02-19 Thread Edward R Cole 
One other consideration,if using metal tools around high current 
sources (like batteries or power supplies): Shorting the terminals 
may cause rapid heating and result in explosions.  An exploding 
lead-acid battery can hit you with shrapnel and acid which can burn 
you, blind you, or cause death!


My wife gave me a wedding ring and I explained that I would not be 
wearing it to work (2-way radio tech).  She understood.  I did wear a 
watch but removed it when working on live ckts.


73, Ed - KL7UW
  http://www.kl7uw.com
Dubus-NA Business mail:
  dubus...@gmail.com 


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Re: [Elecraft] ECOM scare -- FW: Soldering lesson

2017-02-18 Thread Rose 
Even tiny hearing aid batteries ... supposedly "dead" ... among pocket
change can explode with a surprising amount of energy.

73

Ken - K0PP

On Feb 18, 2017 7:34 PM, "Jim Miller" <jimmil...@stl-online.net> wrote:

> It has been a long time but... I had a battery in my pocket (not sure any
> more but probably a 9v), no change in the pocket and do not remember what
> it
> was that caused the problem (probably my knife) but something apparently
> shorted the terminals and I felt uncomfortable, jostled my pocket, then
> warm, then hot and HAD to get whatever it was out.  I burned my hand. The
> battery got MUCH hotter even after it was out.  It would have caused a
> serious burn to my leg had I not removed it.  I could only describe the
> situation as an avalanche failure inside the battery.
>
> I will not forget that experience and never put batteries in my pocket of
> where they can short any longer.
>
> 73, Jim KG0KP
>
> -Original Message-
> From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Don
> Wilhelm
> Sent: Saturday, February 18, 2017 6:01 PM
> To: elecraft@mailman.qth.net
> Subject: Re: [Elecraft] ECOM scare -- FW: Soldering lesson
>
> I was involved in product testing in my former career.
> One large computing machine which I worked on had a backup battery
> consisting of 4 AA cells, which no-one thought would be a problem, but
> during environmental testing at shipping extremes, condensation formed and
> created leakage paths.  It was a hard sell to convince management and many
> engineers that AA cells could cause a problem.
>
> The following action was to do extensive testing in the power systems lab
> in
> which several destructive tests were performed, which included shorting the
> battery pack terminals.
>
> It is amazing how much current those "lowly" AA cells can produce in a
> shorted situation.  Under short conditions, they are just as powerful as
> any
> other battery, but the duration of the huge current discharge is shorter
> than for larger batteries.
>
> Lesson I learned is to be careful with any battery.  High density battery
> chemistries make the short circuit discharge duration longer and can cause
> more damage.
>
> 73,
> Don W3FPR
>
> On 2/18/2017 6:25 PM, Rick WA6NHC wrote:
>
> > Don't forget that some of the battery packs we commonly use now
> > (LiFePo4 is my example) are capable of tremendous current (mine are
> > 'fused' by a BMS at 100 amps).
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Re: [Elecraft] ECOM scare -- FW: Soldering lesson

2017-02-18 Thread Jim Miller 
It has been a long time but... I had a battery in my pocket (not sure any
more but probably a 9v), no change in the pocket and do not remember what it
was that caused the problem (probably my knife) but something apparently
shorted the terminals and I felt uncomfortable, jostled my pocket, then
warm, then hot and HAD to get whatever it was out.  I burned my hand. The
battery got MUCH hotter even after it was out.  It would have caused a
serious burn to my leg had I not removed it.  I could only describe the
situation as an avalanche failure inside the battery.

I will not forget that experience and never put batteries in my pocket of
where they can short any longer.  

73, Jim KG0KP

-Original Message-
From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Don
Wilhelm
Sent: Saturday, February 18, 2017 6:01 PM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] ECOM scare -- FW: Soldering lesson

I was involved in product testing in my former career.
One large computing machine which I worked on had a backup battery
consisting of 4 AA cells, which no-one thought would be a problem, but
during environmental testing at shipping extremes, condensation formed and
created leakage paths.  It was a hard sell to convince management and many
engineers that AA cells could cause a problem.

The following action was to do extensive testing in the power systems lab in
which several destructive tests were performed, which included shorting the
battery pack terminals.

It is amazing how much current those "lowly" AA cells can produce in a
shorted situation.  Under short conditions, they are just as powerful as any
other battery, but the duration of the huge current discharge is shorter
than for larger batteries.

Lesson I learned is to be careful with any battery.  High density battery
chemistries make the short circuit discharge duration longer and can cause
more damage.

73,
Don W3FPR

On 2/18/2017 6:25 PM, Rick WA6NHC wrote:

> Don't forget that some of the battery packs we commonly use now 
> (LiFePo4 is my example) are capable of tremendous current (mine are 
> 'fused' by a BMS at 100 amps).
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Re: [Elecraft] ECOM scare -- FW: Soldering lesson

2017-02-18 Thread Don Wilhelm 

I was involved in product testing in my former career.
One large computing machine which I worked on had a backup battery 
consisting of 4 AA cells, which no-one thought would be a problem, but 
during environmental testing at shipping extremes, condensation formed 
and created leakage paths.  It was a hard sell to convince management 
and many engineers that AA cells could cause a problem.


The following action was to do extensive testing in the power systems 
lab in which several destructive tests were performed, which included 
shorting the battery pack terminals.


It is amazing how much current those "lowly" AA cells can produce in a 
shorted situation.  Under short conditions, they are just as powerful as 
any other battery, but the duration of the huge current discharge is 
shorter than for larger batteries.


Lesson I learned is to be careful with any battery.  High density 
battery chemistries make the short circuit discharge duration longer and 
can cause more damage.


73,
Don W3FPR

On 2/18/2017 6:25 PM, Rick WA6NHC wrote:


Don't forget that some of the battery packs we commonly use now (LiFePo4
is my example) are capable of tremendous current (mine are 'fused' by a
BMS at 100 amps).

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Re: [Elecraft] ECOM scare -- FW: Soldering lesson

2017-02-18 Thread Phil Kane 
On 2/18/2017 2:14 PM, Ron D'Eau Claire wrote:

> I never work around a car battery or other low-voltage, high current supply
> wearing jewelry. If you wear a wedding ring that you cannot or do not want
> to take off, do what hospitals do and wrap a band-aid around your finger
> covering it. 

Another trick is to use a pair of cotton gloves with the
tip-to-first-joint of each finger cut off.

73 de K2ASP - Phil Kane
Elecraft K2/100   s/n 5402

>From a Clearing in the Silicon Forest
Beaverton (Washington County) Oregon
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Re: [Elecraft] ECOM scare -- FW: Soldering lesson

2017-02-18 Thread Rick WA6NHC 
After pain, visual learning is often the best teacher.  The rest of us 
sense wallet depletion.



Don't forget that some of the battery packs we commonly use now (LiFePo4 
is my example) are capable of tremendous current (mine are 'fused' by a 
BMS at 100 amps).


Rick nhc


On 2/18/2017 2:40 PM, Mel Farrer via Elecraft wrote:

AT had a school in Oakland training people how to maintain office 48 VDC battery 
banks.  They had a display of the top of one of the BIG office batteries with a 12" 
spanner some idiot used to tighten the terminals.  The middle of the spanner was gone.  
Point well made.
Mel, K6KBE


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Re: [Elecraft] ECOM scare -- FW: Soldering lesson

2017-02-18 Thread Mel Farrer via Elecraft 
AT had a school in Oakland training people how to maintain office 48 VDC 
battery banks.  They had a display of the top of one of the BIG office 
batteries with a 12" spanner some idiot used to tighten the terminals.  The 
middle of the spanner was gone.  Point well made.
Mel, K6KBE

  From: Ron D'Eau Claire <r...@cobi.biz>
 To: elecraft@mailman.qth.net 
 Sent: Saturday, February 18, 2017 2:14 PM
 Subject: Re: [Elecraft] ECOM scare -- FW: Soldering lesson
   
I worked with a guy missing his ring finger after accidentally getting his
wedding band across the high-current supply bus and the airframe in an
aircraft console. The ring immediately welded to the current source so he
could not move his hand. He said that he passed out from the pain as the
metal melted into his flesh.

Others in the shop spoke of the guy who lost a hand to a metal watch band
the same way. 

I never work around a car battery or other low-voltage, high current supply
wearing jewelry. If you wear a wedding ring that you cannot or do not want
to take off, do what hospitals do and wrap a band-aid around your finger
covering it. 

73, Ron AC7AC 



-Original Message-
From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Bill
Frantz
Sent: Saturday, February 18, 2017 9:20 AM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] ECOM scare -- FW: Soldering lesson

Amen! I shorted my wedding ring and a wrench across a car battery once. It
burned out a small part of the ring, and left a blister that lasted a week.
I was lucky. I also got the ring off before the swelling made it impossible.
I was doubly lucky.

73 Bill AE6JV

On 2/17/17 at 5:16 PM, kev...@coho.net wrote:

>High amperage DC is very dangerous.  You would need to have a finger or 
>hand amputated if your jewelry shorts it out.
---
Bill Frantz        | Security is like Government  | Periwinkle
(408)356-8506      | services. The market doesn't | 16345 
Englewood Ave
www.pwpconsult.com | want to pay for them.        | Los Gatos, 
CA 95032

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Re: [Elecraft] ECOM scare -- FW: Soldering lesson

2017-02-18 Thread Ron D'Eau Claire 
I worked with a guy missing his ring finger after accidentally getting his
wedding band across the high-current supply bus and the airframe in an
aircraft console. The ring immediately welded to the current source so he
could not move his hand. He said that he passed out from the pain as the
metal melted into his flesh.

Others in the shop spoke of the guy who lost a hand to a metal watch band
the same way. 

I never work around a car battery or other low-voltage, high current supply
wearing jewelry. If you wear a wedding ring that you cannot or do not want
to take off, do what hospitals do and wrap a band-aid around your finger
covering it. 

73, Ron AC7AC 



-Original Message-
From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Bill
Frantz
Sent: Saturday, February 18, 2017 9:20 AM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] ECOM scare -- FW: Soldering lesson

Amen! I shorted my wedding ring and a wrench across a car battery once. It
burned out a small part of the ring, and left a blister that lasted a week.
I was lucky. I also got the ring off before the swelling made it impossible.
I was doubly lucky.

73 Bill AE6JV

On 2/17/17 at 5:16 PM, kev...@coho.net wrote:

>High amperage DC is very dangerous.  You would need to have a finger or 
>hand amputated if your jewelry shorts it out.
---
Bill Frantz| Security is like Government  | Periwinkle
(408)356-8506  | services. The market doesn't | 16345 
Englewood Ave
www.pwpconsult.com | want to pay for them.| Los Gatos, 
CA 95032

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Re: [Elecraft] ECOM scare -- FW: Soldering lesson

2017-02-18 Thread Bill Frantz 
Amen! I shorted my wedding ring and a wrench across a car 
battery once. It burned out a small part of the ring, and left a 
blister that lasted a week. I was lucky. I also got the ring off 
before the swelling made it impossible. I was doubly lucky.


73 Bill AE6JV

On 2/17/17 at 5:16 PM, kev...@coho.net wrote:

High amperage DC is very dangerous.  You would need to have a 
finger or hand amputated if your jewelry shorts it out.

---
Bill Frantz| Security is like Government  | Periwinkle
(408)356-8506  | services. The market doesn't | 16345 
Englewood Ave
www.pwpconsult.com | want to pay for them.| Los Gatos, 
CA 95032


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Re: [Elecraft] ECOM scare -- FW: Soldering lesson

2017-02-17 Thread kev...@coho.net 
I was at a Red Cross headquarters working ECOM when the room filled with 
bystanders.  All of the power supplies were facing the operators while 
their exposed backs were next to the crowd.  I noticed a lot of hand 
jewelry.  I got the most important looking person's attention and 
mentioned how a dead short across 40 amps would effect his hand.  Since 
I had only been there a few minutes he looked at me funny and then at 
the exposed wiring.  Soon afterward there was someone covering them with 
tape.  High amperage DC is very dangerous.  You would need to have a 
finger or hand amputated if your jewelry shorts it out.


Kevin.  KD5ONS


On 2/17/2017 5:08 PM, Jerry wrote:

Well, it is pretty obvious to me. Look at the rock on her left hand! She
shouldn't be wearing that while soldering!! That could be a safety hazard!!

Best laughs

Jerry, W1IE

-Original Message-
From: Elecraft [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of
Douglas Hudson
Sent: Friday, February 17, 2017 6:29 PM
To: elecraft@mailman.qth.net
Subject: [Elecraft] Soldering lesson

This is an example of how easy it is to build a kit.

http://www.eejournal.com/archives/fresh-bytes/everything-about-this-beautifu
l-woman-soldering-stock-photo-is-w/
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