[Shop-talk] MIG welder term

[David Scheidt]

On 7/28/07, Bob Nogueira <nogera at worldnet.att.net> wrote:
> Could someone explain to me the term 'Duty Cycle" in reference to MIG
> welders? I figure it means how long you can weld before having to stop and
> allow the welder to recover but why is it expressed as a percentage?
> When they say the duty cycle is 25% does that mean you can weld for 1
> minute and have to wait 3 minutes for the welder to recover? What happens if
> you exceed the Duty Cycle? What's the time frame? How do you know you are
> approaching the limit of the duty cycle ?
>

It's typically over ten minutes.  Twenty-five percent would mean 2.5
minutes on, 7.5 off.  When you exceed the duty cycle, the machine
overheats.  There's typically some sort of overheating protection,
though it's best to not get to the point where it trips in.  Note that
most machines are rated at their maximum output, and have a much
higher duty cycle at lower output.  My mig has a 20% duty cycle at
peak output, but 100% at about 50% power.

Unless you're doing production fabrication, you're unlikely to need
100% duty cycle.  You've got to set up the work, adjust things, etc.

-- 
David Scheidt
dmscheidt at gmail.com