The climate change debate continues.

[facthunter]

That's dumb and irresponsible. I've had good mates who were plumbers die of electrocution working under a house. The LAW is there for a good reason. IF something happens, you could be up for a lot of money. Nev

[willedoo]

One thing I've always thought about getting is one of those portable circuit breakers you can use on the job to plug power tools into. I looked them up and the ones I'm thinking of are called an RCD safety switch.

 

This is from one website:

"Portable RCD's (or Safety Switches) provide added protection when using electrical equipment. RCD's cut the power supply to the electrical appliance if a current leakage fault is recognised (a current inbalance between active and neutral). They are designed to help prevent electrocution. The use of RCD's is rapidly becoming compulsory in many parts of Australia and many working environments. Contact your local safety or workcover office for more information.

RCD's should not be confused with lower cost circuit breakers, which cut power supply when the current draw exceeds a specified level (or in abnormal power conditions)."

[old man emu]

I'm certified (Ha! Ha! Certifiable) todo test 'n' tag of electrical equipment operating on 240VAC. I learned about RCDs and have a portable one to use during testing. When I had my place rewired, I forked out for an RCD in every circuit. Why? Because years ago I cut through the power cord while using a portable circular saw, and the result was that the saw stopped - not me.

 

Remember: Fuses and circuit breakers ONLY save your equipment. RCDs save your life.

[spacesailor]

In the fifties , I bought a ' black ' box that tripped a circuit if you got electrocuted. 

I will now pull it apart t check that ' tripped ' component. I don't think it is high wattage through. 

spacesailor

[pmccarthy]

Back in the 1980s I could get worms by sticking a tent peg into the lawn and connecting the active off the extension cord. All the worms would come to the surface. Then a couple of people died doing it and I stopped. Now you can't do it, it would just trip out.

[spacesailor]

Need a Bigger ' ' contact breaker ' then it will give the worm's  a kick before it ' kicks out ' .

spacesailor

 

[Bruce Tuncks]

How many milliamps does the tripper need to turn off the main circuit?

 

[onetrack]

It only takes 30 milliamps to trip an RCD, and they must operate within 300 milliseconds. A circuit breaker saves wiring and stops fires starting, an RCD save lives. But an RCD can't prevent a short circuit or an overvoltage event.

[old man emu]

7 hours ago, onetrack said:

But an RCD can't prevent a short circuit or an overvoltage event.

So to fully protect a 240VAC circuit, you need an RCD, a fuse and a surge protector. Is that correct?

[nomadpete]

You can get an RCD that incorporates a circuit breaker of a suitable current rating (say 16 amps for a power circuit, 10 amps for a lighting circuit).

 

A fuse is rarely used  these days.

 

If there are multiple power circuits it is common to use a single RCD feeding a row of circuit breakers.

 

 

[spacesailor]

My house had those ' wire ' fuses. One strands 5 amp , two strands for 10 , three strands for 15 amp , & you can see were this is going for that big amperage. 

I put in the contact breaker type in place of the ' wire ' plug-in type .

And some ' as-ol , put an ' asbestos ' sticker on the panel. ( was never their before the quotes )

spacesailor

[old man emu]

Actually, I think I put an RCD on the input to the fusebox and then the electricity flows through circuit breakers. I'll have to check with my sparky.

[nomadpete]

1 hour ago, old man emu said:

Actually, I think I put an RCD on the input to the fusebox and then the electricity flows through circuit breakers. I'll have to check with my sparky.

Usual arrangement FOR A HOUSE is one RCD for lighting, and one for Power.

 

 

[Bruce Tuncks]

OME, there is a "guide to fuse replacement" cartoon which is pretty good.

[Bruce Tuncks]

Apparently a big nail is good for 2000 amps.

[facthunter]

I cut mine shorter than that.  Nev

[nomadpete]

1 hour ago, Bruce Tuncks said:

Apparently a big nail is good for 2000 amps.

I have had the dubious pleasure of proving that.

 

I was testing the wiring in a dark television, in a dark corner of a old terrace house in Sydney. My meter probe bridged the air gap between a loose active wire and a neutral. The flash blinded me for a while. Half of the meter probe vaporised. Then the next door neighbour knocked on the door to ask if our power had gone out, too. Turned out the pole fuse supplying three houses had blown.

 

All because the main house fuse was a 3000 amp nail.

 

That's just a bright flash from my colourful working days.

[kgwilson]

Good quality CBs incorporate RCDs these days. I just installed one for my EVSE device that draws 32 amps. They are called RCCBs (residual current circuit breaker) and it protects you from electrocution and the device you are using from meltdown or burnout etc.

[spacesailor]

At 3000 amps , it would have. ' blown your fingers off ' .

Didn't the American electric chair have a few problems with ' blown fuses ' , & the victim having to sit for another ' try ' .

spacssailor

[red750]

[old man emu]

Today it got to 40C around my area. For most of the day there was a mild wind/breeze blowing, and the air in it was hot. My calendar shows sunrise and sunset on Fridays for Sydney. (Other capitals on other days on the calendar.) We know, as pilots that we can refer to daylight and darkness charts for any place we are or want to go to. If you think about it, those charts also show the number of hours the ground is exposed to the warming rays of the Sun. Those charts don't go out of date. There were the same number of hours of sunlight on the day you were born as there were on your last birthday.

 

So how come to day it got to 40C, but this day last year the temperature ranged from about 10 to 25C?

[red750]

Melbourne was opposite end of the scale. Top temp was around 19 deg, rain all day, some very heavy, and strong winds. It was so dark, lights were required in the house. However, it didn't stop the climate change protesters blocking city traffic for the fourth day in a row. I bet  they are all driving their cars and using electricity in their homes.

[Jerry_Atrick]

Nor should it stop them protesting.. Change doesn't happen overnight, and yes, to get around with our current infrastructure means one has to burnn fossil fuels unless one walks or rides a bicycle - of which I am sure a few if not many did. Just because they have to use the same infrastructure to get around does not mean what they are doing is wrong or hypocritical. The idea is to pressure a change in plicy to move to renewables and more eco-firendly societal lifestyle - preferablky more rapidly.. More and more people are jumping off the denier bandwagon as severe climate change is impacting more and more people; I would suggest the evidence is starting to become more than figures on a graph.

[spacesailor]

RENEWABLES 

Wood fired steam boilers of old ! , Before we found ' black rocks ' burn.

then we " Conserved " forests,  or what was left of them .

Now we chop down the " old growth " forests  for ' brown paper bags ! .

Conservation gone mad .

spacesailor

 

[pmccarthy]

The first COP, held in Berlin in 1995, had just under 4000 delegates. In Glasgow two years ago, 120 world leaders attended alongside 40,000 other registered participants. About 50,000 people gathered in Egypt last year. This year 100,000 are expected, nearly all will be flying.