Please help with "Sticky" thread with safety info and advice

[Fresh_Start]

A month or so ago I got inspired to put together a thread which covered amp building safety.  With the voltages and current inside tube amps, we just can't be too careful.  Unfortunately, I got distracted by other things in life...

So, please use this thread to post links, articles, tidbits, whatever for a SAFETY THREAD.

I'll start it off with the basics from Drifter Amps:
http://www.drifteramps.com/safety.html

Once we've got a good start, I'll try to organize the links in a new thread and then folks can add to it as they see fit.

Thanks!

Chip

[eleventeen]

One thing I like to do...When I strip off the outer insulation from multiconductor or shielded cable, or, when I use Belden 8451 which is twinax, foil shield audio cable....I keep the "tubing" in an empty medecine bottle. When experimenting, we often make temporary solder connections or join wires or two resistors together that just hang in the air. The (otherwise discarded) tubing from these cables is VERY useful to just slip over temporary connections, or, unused wires coming out of a power transformer where you are searching for & testing output volts, to slip over the unused output wires. It's ultimately like using heat shrink, but it is thicker, resusable, and of course, free.

[RicharD]

Great idea Chip.  We have a lot of folks pass through here looking for advice and it's easy to forget that they might not be as experienced or as crazy as some of us.  I am an electrical contractor.  I handle live wires all day long.  I am a lot more comfortable around energized circuit than your average Joe.  I'll work up a safety outline but for now, I'll leave you with a few golden rules:

There's only 1 assumption that is acceptable.  Assume all unknown wires are hot.
If your not 100% comfortable with the situation, DON'T DO IT!
Always use proper safety equipment.  Not having it is no excuse.

-Richard

[Fresh_Start]

Guys - I could use some help here!

Here's another good introductory piece:
http://www.aikenamps.com/SafetyTips.html

Is there something in the Archives worth bringing up to the front?

Cheers,

Chip

[Fresh_Start]

I'm not giving up here!  The problem is that I AM NOT AN EXPERT!!!

http://tubelab.com/Safety.htm

http://www.geofex.com/tubeampfaq/TUBEFAQ.htm#safety

Seriously, please let me know which, if any, of these articles seems particularly helpful.

This from Supro66 is a recurring theme in all of the safety info:

BE THE ONE-ARMED TECHNICIAN - there will come a time when you have to work on a chassis that is running. When doing so, if possible clip one of your meter's test leads to ground, and use only 1 hand to probe the circuit, keeping the other in your pocket etc.  That way if you DO take a shock, your heart is not in line of the path of least resistance -in one arm and out the other.  When you ABSOLUTELY must use 2 hands, be EXTREMELY CAREFUL, and use common sense, but PLEASE try to avoid these situations!

Thanks,

Chip

[RicharD]

Attached is a little 5 page thingy I was working on.  It's hard to write this stuff w/o sounding condescending or being over opinionated.  I have not proofread this.  I typed for a  little while, hit a point of dissatisfaction, saved-n-quit.  Again, this has not been proofread.  My opinion on line isolation caps might be viewed as controversial.  I do not think they are ideal as a sole means of protection, but coupled with proper grounding, they're good to have should you happen to plug into an ungrounded and/or reverse polarity receptacle.  Please feel free to correct.

-Richard

[jjasilli]

Hot chassis.  Use the Jack Darr method or similar.  I'll re-post it if you like.

[Cups]

Very good read butterylicious.

[Fresh_Start]

Hot chassis.  Use the Jack Darr method or similar.  I'll re-post it if you like.

You've read too many of PRR's posts

Please let me know what you are referring to.

Found it:

Safety check for all amps (even if operating normally) Page 47:  connect a 1500R 10W resistor from chassis > ground.  Turn on amp and read voltage across the resistor.  Reading should be near -0-.  Reverse the plug in an old amp.  Also use the line reverse SW if any.  2-3V is dangerous.  Full AC line voltage = a dead short.   

Causes:  a) shorted dead man cap.  b) PT primary shorted to core.  If b) replace tranny.

Thanks,

Chip

[simonallaway]

If someone looks like they are approaching your bench, take precautionary moves to prevent them from touching your work, and electrocuting themselves, and/or you.
Unplug...

I second that. I've had to train my kids to not interrupt me when I have tools in my hand and/or I'm clearly busy with something sharp/hot/dangerous/all-3.

One day I was concentrating hard on routing dovetails in hardwood (I am deeply respectful of routers and their 25,000 rpm tungsten edges). I've got goggles on, and ear-defenders...I have the shop-vac running to catch sawdust, and I'm kneeling on the floor for stability. Do I look like I'm ready for idle chat? Apparently so because my son tapped me on the shoulder! I ignored him at first as I was physically/mentally committed to the cut, but he kept tapping. That was one of the first times I really 'lost it' and had to have a serious talk with them all.

Oh and we've got 6 cats, so it's only a matter of time before one tries to jump up on my bench while I've got a hand in the wrong place. 

[jojokeo]

Good thread Chip.

I was thinking lamp limiter, GFCI, and rubber sole shoes before reading Buttery's attachment but will 2nd these. I run a large reeftank at home w/ high powered halides and other equipment and GFCI's are a must and can't be stressed enough. I also use re-settable fused power strips for double protection on ground faults but you can still get yourself clipped on secondary hits.

there will come a time when you have to work on a chassis that is running

This is almost a daily occurrance for me (i'm sure most others here too).

I think w/ those other good comments and attachments most of the "electrical" stuff is covered? But this isn't only about electrical as noted by Simon. We all need to always think ahead of the worst case scenario regarding ANY potential hazards and situations.
Along this thought, I can't know how many times I've propped something up, stood something up, sat it up...and then in some way or another it falls or slides further. I always try to just set it or lay it down so that it is now at it's lowest potential and cannot "fall any lower or further". I've had live chassis' do this to guitars and amps, bikes, you name it. It can be a chord, wind, animal, it's just not worth it after something happens.

Being impatient and/or in a hurry (carelessness) is almost always the reason for my getting a jolt or sparking my meter's probes.

Although shop fun and hijinx in blowing up old parts is a fun stress release sometimes, it also shows what can happen and the type of force there is by simply applying overvoltage or reversing polarity an e-cap for example.

[Fresh_Start]

The router comments reminded me that almost all of us break out a drill or drill press once in a while.  Secure your work.  Verify that your work is secure. Insert and tighten appropriate bit, THEN plug device in.  Oh, and put eye goggles on before anything else.

A spinning chassis or bit of metal flying toward your eyeball is not a laughing matter.  Please don't ask me how I know about how scary a spinning chassis is.

Also, I get the impression that a lot of guys don't understand about lubricating the bit when cutting metal.

Someone here (Madison maybe?) explained the need to decrease drill speed as the diameter of the bit increases.  The short version is that the greater the diameter of the bit, the faster the outside cutting edge is moving across/through the material being cut.  Big bit, s-l-o-w speed.

Thanks guys!

Chip

[simonallaway]

Someone here (Madison maybe?) explained the need to decrease drill speed as the diameter of the bit increases.  The short version is that the greater the diameter of the bit, the faster the outside cutting edge is moving across/through the material being cut.  Big bit, s-l-o-w speed.

Here's a formula posted in what might be that thread. I had selfishly hijacked it while drilling a steel chassis with a unibit. And I was suffering from ".... you've set your drill rotational speed too high, applied too much pressure and maybe didn't use cutting oil."

http://www.el34world.com/Forum/index.php?topic=8740.msg81052#msg81052

[Ritchie200]

If you have kids, grandkids, teens who are at the age of all encompassing knowledge - cover, lock up, reassemble to safe point, close and lock the door when you quit for the day, go to lunch, even answer the phone.  And yes kitty cats "fall" into this category too.  They will poke and prod to be like/see what dad, granddad, older brother, room mate, etc.....is working on.  Kind of a innocents lockout-tagout.

Oh yeah, eye protection on a startup and when poking your test probes around in a live circuit is not a bad idea either. 

Jim

[simonallaway]

If you have kids, grandkids, teens who are at the age of all encompassing knowledge

[Fresh_Start]

Thanks guys!  Great info, especially that link Simon provided.

Work is getting in the way of my hobbies at the moment, but I will tackle assembling the contents of this thread into a more accessible format in the next week or two.

At least I have work to do!

Chip