NAPIT the accusators

[phil d]

Sidey, that's interesting about faults in connected appliances, so how would that go on with say an arc welder? I know that most of them consist of a large transformer and as such have no direct connection to the mains, but a lot of the newer ones don't. I have 3 units, one conventional, one HF tig unit and an invertec DC unit, there's no transformer in the invertec unit,it works by electronics. The reason I'm asking is I remember working on a hospital refurb and they started having issues with one of the scanners, the guy came out several times before he found the problem. Apparently it was a welding set that was being used to install medical gas lines and it was sending interference back into the mains and upsetting the scanner, so with this in mind is it possible that welding equipment could upset an afdd?

 

[Sidewinder]

It should not as for compliance with the current product standard for arc welding power supplies (all types of arc) requires the "welding" side to be electrically separate from the mains.

They must also meet the specification for conducted and radiated emissions as per the EMC directive.

Any welding set which has an electrical connection between the "welding"/secondary side and the primary / mains side is now considered dangerous to use, & is illegal for use in a workplace.

 

[Andy™]

It should not as for compliance with the current product standard for arc welding power supplies (all types of arc) requires the "welding" side to be electrically separate from the mains.

and so they should be. common occurance to touch the earth / electrode, which would result in a shock if it wasnt isolated from the mains

 

[phil d]

and so they should be. common occurance to touch the earth / electrode, which would result in a shock if it wasnt isolated from the mains

all of my welders are fairly new, only got the latest one last month, Andy, I take it you've not done much welding then? In a damp environment, you can still get a nasty belt off a welder, especially if you happen to be kneeling on the steelwork you are welding and you go to change a rod without gloves on.

 

[Sidewinder]

You will Phil, but, that is from the welding side, not the mains side.

If your welding return is connected to a piece of equipment that is not connected to true earth, yet you are, but, you are not in contact with what the welding return is connected to then you cannot get a shock.

Generator sets are the worst when you are doing big metal things (think mobile plant on steel tracks) on site, and you are soaking wet!

You can't avoid the "tingle", but, a good tip, is nitrile gloves inside your welding gauntlets, try it you'll be surprised as long as your wrists don't contact iykwim.

 

[phil d]

You will Phil, but, that is from the welding side, not the mains side.

If your welding return is connected to a piece of equipment that is not connected to true earth, yet you are, but, you are not in contact with what the welding return is connected to then you cannot get a shock.

Generator sets are the worst when you are doing big metal things (think mobile plant on steel tracks) on site, and you are soaking wet!

You can't avoid the "tingle", but, a good tip, is nitrile gloves inside your welding gauntlets, try it you'll be surprised as long as your wrists don't contact iykwim.

Mains side or transformer side it still bloody hurts! lol No, I was thinking more about some kind of interference coming back from the welder and affecting the mains, a bit like motors used to do years ago, remember when the hoover used to make the tv go funny. I can see all kinds of potential problems with these AFDDS, and tbh until somone can convince me of the value of them I'll just pretend they don't exist.

 

[Sidewinder]

They are "supposed" to be immune to conducted EMI from devices, and identify an arc signature according to specific parameters.

One of which is a 2 - 2.5A arc current!

 

[phil d]

They are "supposed" to be immune to conducted EMI from devices, and identify an arc signature according to specific parameters.

One of which is a 2 - 2.5A arc current!

I love the way you use the word 'supposed' is that like when someone says, "that bracket is solid" or "that ladder won't slip" or any of the numerous fibs, we've all been told over the years. lol

 

[Andy™]

all of my welders are fairly new, only got the latest one last month, Andy, I take it you've not done much welding then? In a damp environment, you can still get a nasty belt off a welder, especially if you happen to be kneeling on the steelwork you are welding and you go to change a rod without gloves on.

thats between the electrode and the welders earth where you have an path for current to flow. between the electrode (or welder earth) and the ground youre standing on you shouldnt get a shock. same as a shaver point. might be 230v, but you shouldnt get a shock from touching 1 side of it. touch both sides and you will have 230v and a shock

you also shouldnt make assumptions. ive done plenty welding for over 15 years. mig, tig, stick, gas, in all situations, nice dry indoors, ****ty weather outside etc. i also own 5 (or is it 6? cant remember) welders. newest inverter welder is <6 month old. 300a stick is probbaly 20 years old with transformer... i suggest you go back to playing policeman. got to e a crash somewhere for you to go 'assist'

 

[Sidewinder]

thats between the electrode and the welders earth where you have an path for current to flow....

It's more correctly now called the Welding Return.

 

[phil d]

thats between the electrode and the welders earth where you have an path for current to flow. between the electrode (or welder earth) and the ground youre standing on you shouldnt get a shock. same as a shaver point. might be 230v, but you shouldnt get a shock from touching 1 side of it. touch both sides and you will have 230v and a shock

you also shouldnt make assumptions. ive done plenty welding for over 15 years. mig, tig, stick, gas, in all situations, nice dry indoors, ****ty weather outside etc. i also own 5 (or is it 6? cant remember) welders. newest inverter welder is <6 month old. 300a stick is probbaly 20 years old with transformer... i suggest you go back to playing policeman. got to e a crash somewhere for you to go 'assist'

courgette YOU, SARCASTIC Fennel!

 

[Andy™]

changes name just as often as 7671

courgette YOU, SARCASTIC Fennel!

:slap

 

[Andy™]

:slap