On Tue, 6 Jun 2023 20:12:24 -0700 (PDT), Phil Allison
<
palli...@gmail.com> wrote:
> legg wrote:
>-----------------
>>
>> DC ratings of standard breakers seldom exceed 40V, due to arcing.
>>
>
>** However most *mains rated* breakers employ magnetic or physical barrier arc quenching whenever contacts open.
Not so much quenching, as sacrificial absorption, in locations that
are not relied on for physical working contact area. Life-limited,
bulky and $$$.
>
>> AC arcs are interrupted by line voltage reversal,
>
>** Strange how AC arc welders work so well then.
Wadabaudit? Nobody's saying that AC won't arc.
They don't work so well, because an arc has to be re-established
on every cyclic reversal. Breaking the AC arc is 'easy'. Maintaining
one is hard. AC arc welding produces spatter. Industry preference
is for smooth.
What AC welding is, is cheap.
Sometimes, for some types of metal, or for delicate work, having
an easily broken arc, or repeatedly forcing a restart has an
advantage. For highly magnetic material, it avoids 'wandering'.