Duty Cycles

Date 07-30-2004 15:38

Hi Matt,
This describes duty cycle some...
http://www.zena.net/htdocs/FAQ/dutycycle.shtml
[edit..I'm not pushing these welders, because I never heard of them before. I included the link because the definition was pretty good at the top of their page.]

Here's what AWS A3.0-94 Standard Welding Terms and Definitions says...

"Duty Cycle=The percentage of of time during an arbitrary test period that a power source or it's accessories can be operated at rated output without overheating."

Good question,
John Wright

By thirdeye (***)

Date 07-30-2004 15:42

Matt,

Welcome to the forum!

Duty cycle is the percentage of time during a specified operating period that a piece of equipment can be operated at rated output without overheating. Most welding machines are rated in intervals of 10 minutes meaning that a duty cycle of 50% means that the machine can be operated at a given amperage setting setting for 5 minutes without damage to the equipment. 80% would give 8 minutes.

By CHGuilford (****)

Date 07-30-2004 16:23

Matt,
I just want to add that duty cycle applies to actual welding time, not the time the power switch is "on". The time the machine is idle counts as the cooling time percentage. You will hear the cooling fan running but heat is not being produced in the transformer.

100% duty cycle is nice but not necessary for hobby welding. I would look for versatility, easy to use controls, and a good warranty rather than be overly concerned with duty cycles.

I've never heard of "Clarke" brand but that desn't mean anything. I will say that you usually get what you pay for.

Chet Guilford

By 357max

Date 07-30-2004 18:52

Duty cycle refers to the per centage of a 10 minute cycle that a machine can operate at rated output or load which is volts times the amps. This equals wattage, if volts or amps or both are reduced the duty cycle is increased. European made machines are usually rated on a five minute cycle. That means a 60% duty cycle is different depending on if you have five or ten minutes to build up heat inside the machine. Also they may show a very low amperage input or primary. This will be if they show a 100% duty cycle. That is at a very low amperage and voltage there is very little heat built up inside the machine. If the machine has a thermal overload (gets to hot) protection device the weld output shuts off and the fan usually runs. If it doesn't have this device the welder determines when the machine gets too hot. Usually the duty cycle is not rated at the machines maximum output of voltage and amperage.

By matttyrrell Date 07-31-2004 07:31

Thanks jwright650, thirdeye, CHGuilford and 357max!

By Northweldor (***)

Date 07-31-2004 11:28

The Clarke brand is, I believe, of Italian manufacture and has been around for some time, but is very likely to have plastic parts where metal is used by others. I also notice that a chain of stores in my area (Canada) has recently dropped Clarke in favor of Lincoln, and this is often a sign that they were having reliability problems. You are probably better off doing as recommended on this forum many times before, and paying a bit more for a brand that has a long history and will be around when you need parts.