Duty Cycle means “how long something will work for before it overheats”.

Duty cycle is a welding equipment specification which defines the number of minutes, within a 10 minute period, during which a given welder can safely produce a particular welding current.

For example: a 250 amp. Welding machine with a 30% duty cycle must be “rested” for at least 7 minutes after 3 minutes of continuous welding.

Formula for the Estimation of Duty Cycle other than rated outputs:

Example: 200 Ampere Power Source rated at 60% Duty Cycle and operated at 250 Ampere (as far as permitted):

This means that the power source has to be operated maximum 3.8 minutes with a current of 250 Ampere (according to the 10 minute cycle).

Formula for the Estimation others than rated output currents at a specified Duty Cycle:

Example: The maximum output current at a duty cycle of 100% (according to 10 minutes duty cycle) can be calculated by:

Reference: AWS Welding Handbook 9th Edition – Welding Processes Part 1 Volume 2.

Keep reading, happy welding

Thank you,

KP Bhatt