Yep, thanks for the detailed info, good education on overseas wiring. I did a quick Google, and it looks like 2.5mm is 14awg, which is good for 15a 120v. And sadly, I've seen some of that in houses built in the 60's, and just shake my head, it seems so stupid to build things _just good enough_, when the cost to make it much more robust is literally pennies per drop, to go to 12awg. Crazy. I only install 20a circuits, and only use 10awg wire for them. No issues with voltage drop, and less chance of overheating wires if something goes wrong.

We wire them up a little bit differently this side of the pond.

https://en.wikipedia.org/wiki/Ring_circuit

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Kevin

As for 240 being lethal, well, I used to do appliance repair for a while and have worked with it fairly regularly, and have to admit, I've been bitten a couple times by it. 120 will wake you up, 240 will remind you who's boss. Wasn't lethal, but I guess I might be lucky as well. And probably was not securely grounded, thank god. ;-)

LOL. Have to agree with your assessment on the 240. Having been bit a few times myself. With 120, I used to probe around the guts of radios with my finger to trace the 120V circuits. Just tingles a bit.

Got across 3KV once in a radar course lab test. I came out OK. Not the person behind me which I clobbered in the face with my elbow from the muscle contraction.

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Seti@Home classic workunits:20,676 CPU time:74,226 hours

A proud member of the OFA (Old Farts Association)

Yep, something similar happened to me when I was probing around an Asko compact dryer. Was doing the final cleanup inside after testing, maybe a 30-45 second task, so instead of reaching way over behind the machine and test bench and unplugging it, I thought it'll only be a second, no biggee, and when reaching down inside the front, I came in contact with the non-shielded push on connectors for the door switch, which being an Asko, was running at the full 240v.

I obviously didn't see it, and when my hand touched it, the muscles in that arm involuntarily contracted, which in itself shouldn't have been a problem. But a small sharp triangle shaped piece of sheet metal somewhere in there that the meat of my palm, a bit below my thumb, came in contact with on the way out made it one.

Now That was a mess, I think I ended up with 3-4 stitches from that one, after first grabbing some paper towels and electrical tape to bind it up with. Fortunately for me it wasn't too deep, more of a mess than a serious injury, but as it had happened when I'd been in that field of work for less than a year, it was a very valuable learning experience, and rarely got bit from that time on. Not sure which hurt worse, the cut, or the inside of my bicep where it grounded to, that is some thin, sensitive skin...

Lockout tagout and all that business. ;-)

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I think that because we are used to the way 240V bites we tend have a fair in-built level of respect for mains supplies. Assume it's live until proven to be isolated, then check again.
The normal maximum draw on a UK ring main is 3kw on a single outlet, or 6kw on a single (ring) circuit (multiple outlets). It can be a bit of a surprise when one encounters a spur or star circuit, with a 10 or 16A breaker and one tries to draw a bit more - say by plugging in one's old 2kw kettle or 3kw fan heater... More frustrating are the supplies in some public places which have 16A-3pole "commando" outlets which are protected by a 5A breaker - I'll let you work out what phrases are employed of sound/lighting techs who try to use one of these circuits.....

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Bob Smith
Member of Seti PIPPS (Pluto is a Planet Protest Society)
Somewhere in the (un)known Universe?

I am not a sparkie so have a tendency to be very careful when working on mains supplies.

One time I got bitten was when working in an office inside an old warehouse, I had plugged a small fan into the circuit and my mate gave me a shout when I pulled the right fuse to isolate that circuit. All I had to do was change a couple of damaged sockets, not a hard job but in the process I managed to touch the live (disconnected) wire, it got me.

What I had not taken into consideration was the wiring was running inside a steel conduit with other live circuits for a couple of 100yds between the fusebox and the office, when I checked with a high resistance meter (Fluke) there was about 180v showing on that circuit!!!

I now double check before applying fingers :-)

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Kevin

Yeah, just read thru that Wiki. Interesting way to do it, and my first thought was I bet this was implemented during the war, to save copper. It mentioned that this is a popular belief, but supposedly isn't accurate. I'd have to think if not the main reason, I bet it was part of the consideration. That said, I guess I'm more in favor of dedicated circuits, probably because I'm used to them, but it sounds like other than the UK and it's territories, it really didn't catch on in the rest of the world?

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I now double check before applying fingers :-)

Yep, my Fluke meters are well used, and I've even sent them back in for calibration once since I bought them, as I like the confidence that having them re-certified after a number of years of (ab)use gives when working with higher voltages. And now that my business is in a commercial space, and I have 480 as well as 240, 208, and 120 (single and 3 phase), I Really like to know whats what. THAT will definitely kill you, and I don't mess around with it, I call an electrician for that fun.

Partly due to not being comfortable with it, partly because if something goes wrong, and it gets traced back to something I did incorrectly, or even maybe correctly but because I am not a licensed electrician, there is a good possibility that I could have a very unpleasant conversation with my insurance company, about the status of my policy at that point. Rather pay the $ for one, even though it isn't cheap, than take the risk, what with 10 other businesses in my complex, the potential liability could be huge. No thanks.

Speaking about 3 phase, do you guys do anything unusual with that service over there? I have to assume you have it as well, are your voltages wonky, or just your Hz? I know that you're at 50, and we're at 60, anything else that you know of?

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Yeah, just read thru that Wiki. Interesting way to do it, and my first thought was I bet this was implemented during the war, to save copper. It mentioned that this is a popular belief, but supposedly isn't accurate. I'd have to think if not the main reason, I bet it was part of the consideration. That said, I guess I'm more in favor of dedicated circuits, probably because I'm used to them, but it sounds like other than the UK and it's territories, it really didn't catch on in the rest of the world?

It was a different world when that was done, in them days standards were set up more on a country basis rather than a world wide one, but the problem is you can modify and improve set standards but its not so easy to change from one standard to another.

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Kevin

Speaking about 3 phase, do you guys do anything unusual with that service over there? I have to assume you have it as well, are your voltages wonky, or just your Hz? I know that you're at 50, and we're at 60, anything else that you know of?

415v 3 phase is the next standard, or to be honest is the reason for 240v - a single phase to return on 415 is 240, I have seen power cuts in residential areas where a third of properties have lost power.

Anything above that I have never had to deal with, so no idea.

The only other standard that we have is on (construction) site is 110v but that is centre weighted ie: +55v to -55v.

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Kevin

Speaking about 3 phase, do you guys do anything unusual with that service over there? I have to assume you have it as well, are your voltages wonky, or just your Hz? I know that you're at 50, and we're at 60, anything else that you know of?

415v 3 phase is the next standard, or to be honest is the reason for 240v - a single phase to return on 415 is 240, I have seen power cuts in residential areas where a third of properties have lost power.

Anything above that I have never had to deal with, so no idea.

The only other standard that we have is on (construction) site is 110v but that is centre weighted ie: +55v to -55v.

Now that's another interesting tidbit for your construction 110V. I think once you get past 240 or 277V lighting circuits, the rest of the world pretty much does anything higher like 415, 460 or 600 the same world wide. Only difference that comes into play at the higher voltages are the transformer configurations like delta-delta, delta-wye or delta-star for example.

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Seti@Home classic workunits:20,676 CPU time:74,226 hours

A proud member of the OFA (Old Farts Association)

The 110v on construction sites is for small portable equipment and work lights. One (apocryphal) reason being that such equipment will burn out if run on our 240v mains supplies...

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Bob Smith
Member of Seti PIPPS (Pluto is a Planet Protest Society)
Somewhere in the (un)known Universe?

Just a funny aside because of the mentioned 50Hz standard in the UK. On my first training trip over for a month long course, I spent time watching TV over there. I could not understand how the locals could watch it because of the 50Hz line rate that was blatantly obvious to me. I mentioned the effect and questioned people and they had no clue what I was describing or talking about and thought I was speaking gibberish or seeing things. They saw no problems with the TV. Finally came to realize the brain adapts to visual stimulus and anyone exposed long enough just doesn't have awareness of inconsequential data. By my 3rd or 4th trip over my brain had adapted to the 50Hz refresh rate and I no longer noticed the rolling scan line unless I focused on it and made the mental switch.

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Seti@Home classic workunits:20,676 CPU time:74,226 hours

A proud member of the OFA (Old Farts Association)

The lethality of 220/240V we see here is due highly in part of the 60Hz we have, It is more deadly than 50Hz since it is closer to a heart rate.

One thing I was taught with electronics is the one hand in pocket rule with high voltage. Current going through your body from top to bottom is less of a problem than across your chest. So if you only contact with 1 hand it is less sever. Still bloody hurts though.

If you are unfortunate to be in contact with the voltage for long enough for the current to find the arteries or veins, it will use them as the least resistance path to travel to ground. Getting a hand across the circuit and traveling along your arm to exit the elbow to ground really messes you up with the damage. Easy to lose a hand or arm to the necrosis that can set in. An electrical shock can do major damage if is doesn't kill you outright. I always tried to limit the distance from my meter probe hand to ground by deliberately keeping my wrist or forearm in contact with the nearest metal part of the chassis. You never want the circuit to complete across your chest and heart.

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Seti@Home classic workunits:20,676 CPU time:74,226 hours

A proud member of the OFA (Old Farts Association)

The lethality of 220/240V we see here is due highly in part of the 60Hz we have, It is more deadly than 50Hz since it is closer to a heart rate.

One thing I was taught with electronics is the one hand in pocket rule with high voltage. Current going through your body from top to bottom is less of a problem than across your chest. So if you only contact with 1 hand it is less sever. Still bloody hurts though.

Yeah, I can attest to that one...

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The lethality of 220/240V we see here is due highly in part of the 60Hz we have, It is more deadly than 50Hz since it is closer to a heart rate.

One thing I was taught with electronics is the one hand in pocket rule with high voltage. Current going through your body from top to bottom is less of a problem than across your chest. So if you only contact with 1 hand it is less sever. Still bloody hurts though.

Yeah, I can attest to that one...

We've grown up all our lives with it here and it doesn't seem to have caused us too many problems, but the difference in actual power efficiency more than makes up for it I'd say. ;-)

Cheers.

We've grown up all our lives with it here and it doesn't seem to have caused us too many problems, but the difference in actual power efficiency more than makes up for it I'd say. ;-)

Cheers.

Yes, I agree with that. The power efficiency is one major component often overlooked or deemed immaterial. I think it a big feather in its cap.

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Seti@Home classic workunits:20,676 CPU time:74,226 hours

A proud member of the OFA (Old Farts Association)

Photos will be mandatory.

Got a problem, the last picture hosting service I used postimg.org seems to have gone AWOL, whats the easiest hosting site nowdays, I do not use facebook etc.

Delivery expected in 3 - 4 hours.

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Kevin

Photos will be mandatory.

Got a problem, the last picture hosting service I used postimg.org seems to have gone AWOL, whats the easiest hosting site nowdays, I do not use facebook etc.

Delivery expected in 3 - 4 hours.

imgur is mostly what's used, now that Photobucket charges to host pics... I use imgur, now.


TL

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TimeLord04
Have TARDIS, will travel...
Come along K-9!
Join Calm Chaos

imgur is mostly what's used, now that Photobucket charges to host pics... I use imgur, now.


TL

Just signed up to it.

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Kevin