Scope´s ground

You where lucky if the shock had been over 40 mA it would of killed you. It don't take much 40 or less hurt your muscles over that and you more or less lucky if you live and it hits your heart.

At a well known fast food joint here in the north west.
An employee reported that a sink was live to the manager (which was a wiring fault), I dont know what the manager was thinking but in disgust he went out into the kitchen and proved to the employee there was nothing wrong with the sink by grabbing it and the fridge or whatever metallic was next to it tightly, bang that was the last thing he did.
Naturally after that they went really keen on electrical safety.

dr pepper said:

At a well known fast food joint here in the north west.
An employee reported that a sink was live to the manager (which was a wiring fault), I dont know what the manager was thinking but in disgust he went out into the kitchen and proved to the employee there was nothing wrong with the sink by grabbing it and the fridge or whatever metallic was next to it tightly, bang that was the last thing he did.
Naturally after that they went really keen on electrical safety.

Click to expand...

When I used to play in a pool league for my local pub, we went to a pub in Chesterfield and the fruit machine there was live (being a TV engineer I never 'touch' anything metal without stroking it with the back of my hand first) - I told the manager, but he didn't seem interested

I presume it was missing the earth connection, and was just leakage through the filter components - rather than been fully live.

We had a 208/120 system. 240 V heaters, 120 V valves. and they wanted to make it safer for the process when running at night unattended.

A power fail for a long time time meant closing the bell jar (gate valve), turn off the heat source and close the foreline valve and hopefully the LN2 replacement system went down too.

It saved the samples, but the machine needs a days cleaning.

The idiots that made these shutdown systems did not believe in a neutral and all of the wires were yellow. Comment: It's worked for 20 years, why fix it now.

In reality, it could handle itself for 5-10 minutes as it was.

So, no money to fix an electrical hazzard (powered by ground and not neutral) on about 5 machines and no incentive to do it comprehensively.

A diffusion pumped bell jar system doens't like being left alone under pumping when there is a probability of a power failure.

I worked there for a while before I discovered the issue. Managers were deaf.

Sounds a similar problem to me on more than one occaision.

Around '05 in this country (UK) they decided to change the wiring regs into bs7671 I think it is, this also changed the colour codes, they were:

Red L1
Yellow L2
Blue L3

Black Neutral

After bs7671:

Brown L1
Black L2
Grey L3

Or:

Brown L1
Brown L2
Brown L3

Blue neutral

So Blue was a live on the old system, and neutral on the new system, and Black neutral on the old now a live on the new, sensible!!!
Not long after that I plugged my 240v 9" grinder in to a recently fitted 240v socket and got 2 phases, 440v instead of 240v, lucky for me the grinders brushes disintegrated before it went quick enough for the disc to fly apart, there have been other instances since, fortunately not as dangerous.