New Google Classroom update makes it harder to cheat on quizzes | 25 Amp Circuit Breaker

I have been hit HARD by one leg of 440v, 3 Phase power running the 2.5 HP motor of industrial manufacturing equipment. I was on a cement floor, and wearing combat boots at the time. I am sure that helped, but my right arm and shoulder hurt with a strong, but dull ache for over a week afterwards.

I understand it’s only about 20hz, which is why it gives you that interesting jiggly feeling instead of a good Wack like mains power at 50/60 Hz does. When I was still a young buck in my early 20’s I worked in a mid-sized company and one of my duties was to maintain our POTS lines; my boss who might have been a sadist would often have me remap the phone lines mid day while the lines were in use and insist that I was not to busy any lines out. I can only amagine my coworkers delight at the inventive array of profanity that would come out of the wire closet when the reception switchboard would light up during these sessions. Sti got my lines man’s handset stashed somewhere…lol

Funny story : one of my friend had a real electrical problem in his house : earth not well connected or whatever. You could get shocked by touching an USB shield while bare foot. Handling something without a case like a raspi was a living hell.

Potential starting relays consist of a high resistance coil and a set of normally closed contacts. The coil is wired between terminals 2 and 5, with the contacts between terminals 1 and 2.

A big oversight is that outlets are frequently wired backwards with the live and neutral switched. The outlets could be tested first but that kind of defeats the purpose of this thing. Also most houses will have all the outlets in one room be on one branch.

The standard phrase in our repair shop was “electroplated’… as in …”I took that old CRT out and whoosh…. I damn near electroplated myself into the middle of next week when I touched the bottom of the LOPT”…. electrocution was reserved for politicians… as in “….how the hell could there possibly be enough numpties in this country to electorcute that old hag Thatcher…”

More notable recent Amazon.com, Inc. (NASDAQ:AMZN) news were published by: Benzinga.com which released: “Analyst: FANG Stocks Growth Fundamentals Remain Relatively Strong (NASDAQ:FB)(NASDAQ:AMZN)(NFLX)(GOOGL) – Benzinga” on November 27, 2018, also Seekingalpha.com with their article: “AWS signs on in Oracle’s JEDI suit – Seeking Alpha” published on December 17, 2018, Benzinga.com published: “Munster: Amazon Buying Target Still Makes Sense (NYSE:TGT)(NASDAQ:AMZN) – Benzinga” on December 17, 2018. More interesting news about Amazon.com, Inc. (NASDAQ:AMZN) were released by: Nasdaq.com and their article: “A Foolish Take: Amazon Will Rule the US Smart Speaker Market in 2019 – Nasdaq” published on December 24, 2018 as well as Nasdaq.com‘s news article titled: “Where Amazon (AMZN) Is Working With Blockchain – Nasdaq” with publication date: December 13, 2018.

The basic concept of your point is looney. Voltage doesn’t cause heat, The only thing heat dependent for a given installation is the current – of which 120 volt charging is usually less than 240.

So, you agree with 3mm. Good. A step forward. And because I see you want to use that Industrial standard as example how is your standard looking in case of soldermasked and conformal coated board? What I can say is that I used the 3mm/kV rule and never failed me in 25 years, no board rejected ever…and for the sake of the discution, as you know, when we are under 500V/10A circuits things looks a bit different in PCB Design. We are not sending nobody to the Moon nor switching a 500A Engine starter. It’s a max 300W lighbulb Switch and it’s 99.99% safer than the latest zilions of made in China dimmers and fake USB SMPS Mobile Chargers that arrived in your city in the last month.

Point is, there are already pretty well established and widely accepted methods for uniform heating. Why re-invent the wheel AND sacrifice safety?

My post outlines the PME system. There are older systems that do run an earth / ground but they are being removed as and when they need attention. The US system is different but the number of countries using the US system is much less than the number of countries that use a similar system to the UK. I am UK based and UK trained.

My own maxim is that just because something can be – and perhaps often is – done poorly or hazardously does not at all preclude any possibility that it can be done properly and safely.