Safety Best Practices for Computer Work

[pupthai]

If anything can go wrong it will.

I worked in a high level RF environment and was working on an alarm box that was tagged out and had been grounded - but seems during the time I was working the filter caps inside took a small charge back.  I touched one and while it was not going to do anything but zap me a little I stepped back so fast and hard I broke the toe of the poor sole standing behind me.  Ooops - sorry about that.

Worst case I had was a radar test set just back from cal. Shop and repair.  They connected the a/c wrong and the case was hot.  I was standing on rubber matting and holding  the cable connector to screw on to the wave guide in one hand, I then reached over to remove the cap from a test port on the wave guide which makes a nice path to ground - this putting 120VAC 60Hhz right across my heart from one hand out the other.  It almost killed me - and it really hurt.  Needless to say I was vary upset.

I never again trusted a piece of equipment I had not checked myself before use.  You only die once.

[horusfalcon]

If anything can go wrong it will.

Still true to this day - Murphy's Law will never go out of fashion.

{snipped:  true tales of technical terror - best read in the original...}

I never again trusted a piece of equipment I had not checked myself before use.  You only die once.

Yup, listen up, folks!  The pup is tellin' it right!  Learn how to put a multimeter to good use, or, alternatively, follow good grounding and bleed-down practices for your equipment.  (Most of us won't have to face a radar system on our kitchen table, but the principle is the same, and so is the result if you don't heed the principle.)

Keep 'em comin', folks.  I'd love to hear from anybody who's ever put screwdriver to case screw here.  Great stuff!

Later On,
D

[horusfalcon]

Great Thread idea, thanks horusfalcon. Great discussion area also.

One point I was taught when studying Electronics and Computer Engineering / Workshop: when working on a "Live" circuit, which is one of the more Dynamic of situations, have one hand in your pocket.
Our Supply in Australia is 240V AC, 50Hz.

6 milliamps (0.006 Amps)  across your Heart can Kill you.

The idea is; if right handed put your left hand in your left pocket, work with your right hand. The current if you do hit it will be re-directed down your left leg to ground, rather than across your chest, and Heart.
This is for a workbench situation, like working on a Live Circuit, i.e. Computer, T.V.

Yup, I'm left-handed, but I still tend to keep my left hand in my pocket when the gear's hot.  That current is going to find the shortest path to ground, and you don't want that being across your heart.

There are generally a lot of "missed opportunities" in electrical and electronics tasks where folks will work hot because they don't stop to think about the work (which is one reason why a work plan of some kind is important - it should include the "path to safety" for the work). 

Work hot only when you absolutely have to (yeah, I'll keep repeating that every so often - it's worth it.).  Any other time, kill the power, ground the system, and bleed down stored energy sources.

Yeah!  I'm glad to see participation here - the more the merrier (and, hopefully, the safer we all work)!

Later On,
D