cellulose electrode

[PTvor]

Apart from the fact that most inverters have an OCV of over 50V

See here:
http://www.decaweld.com/default.asp?cmd=getProd&cmdID=19306

and cellulosic capable inverters generally have an OCV of 80V plus.

You can't use cellulosics, or for that matter lo hys, on a buzz box with an OCV of 50V.

With an inverter with intelligent control the OCV could be 10V just to detect that a rod is being struck, then it can throw everything at it for 10mS to establish the arc, then go to the set current and look at the voltage across the arc, then decide on the rod being used and select a characteristic suitable for the rod.

Anyway, in the old days when arc welding machines had OCVs of up to 110V on the high voltage range, it was hardly a case of people dropping like flies when they used them.

My own inverters have a claimed OCV of 90V, measured to be 81V, but I've never felt so much as a tingle from them.

 

[denlow60]

Apart from the fact that most inverters have an OCV of over 50V

See here:
http://www.decaweld.com/default.asp?cmd=getProd&cmdID=19306

and cellulosic capable inverters generally have an OCV of 80V plus.

You can't use cellulosics, or for that matter lo hys, on a buzz box with an OCV of 50V.

With an inverter with intelligent control the OCV could be 10V just to detect that a rod is being struck, then it can throw everything at it for 10mS to establish the arc, then go to the set current and look at the voltage across the arc, then decide on the rod being used and select a characteristic suitable for the rod.

Anyway, in the old days when arc welding machines had OCVs of up to 110V on the high voltage range, it was hardly a case of people dropping like flies when they used them.

My own inverters have a claimed OCV of 90V, measured to be 81V, but I've never felt so much as a tingle from them.

MOS 138Evo - 130 Amp - 230V 50/60Hz

this is not OVC but 50/60Hz
at 230V mains voltage is 110V safe
at 400V mains voltage is 42/50V safe

 

[PTvor]

MOS 138Evo - 130 Amp - 230V 50/60Hz

this is not OVC but 50/60Hz

In that case I may need new glasses, but the specification seemed to read

Open circuit voltage (Volt): 75

which I took took to mean that if you connected it to the mains and connected a voltmeter across the welding outputs it would read 75V.

In other words that the OCV was 75V.

 

[denlow60]

In that case I may need new glasses, but the specification seemed to read

Open circuit voltage (Volt): 75

which I took took to mean that if you connected it to the mains and connected a voltmeter across the welding outputs it would read 75V.

In other words that the OCV was 75V.

at 230V mains voltage is 110V safe
at 400V mains voltage is 42/50V safe

 

[PTvor]

at 230V mains voltage is 110V safe
at 400V mains voltage is 42/50V safe

What on earth are you talking about?

Mains voltage has nothing to do with it. Almost all welding machines' outputs are islolated from the mains anyway, so are floating.

Fatal shock is about current across the heart, 50 to 60 Hz being particularly dangerous and it takes at least 30mA to stop the heart. Deaths have been recorded with 36V AC mains on US farms in unusual circumstances, but in usual conditions, dry skin and footwear, you wouldn't notice anything.

When welding you'd normally be wearing leather welding gloves and sensible shoes and the flux on the rod is a poor conductor. Changing the rod is about the only realistic opportunity to be connected across the output of an arc welder.

Welding while sitting in the bath is definitely a bad idea, but most of us are naturally disinclined to do that.

 

[candor]

Does ocv just apply to a.c. machines? I have a dc output machine that has 50v and 70v outputs?

 

[denlow60]

Dangers of electric current

• Safe voltage AC 50V DC 110V

• Transformers with an open voltage that is dangerous must have a voltagereduction relays.

 

[madkayaker]

Let's not start getting mains voltage current and earth confused with welding voltage current and earth.



Unless your very very unlucky (pace maker user some heart conditions or skin conditions) you will not be at risk of electrocution from the output of a welder. The output is isolated from mains and the real earth (the big thing your stand on) you sometimes get a tickle from changing rods if on wet grass etc which while unpleasant will not kill you.


With high current dc if you wrapped a lead around your chest and started welding you can cause breathing difficulties but most people aren't that stupid The rest tend to stop welding when they pass out