Industrial Arc Welder Issues

[aelectricalman]

I'm looking at a group of industrial arc welders that are all fed off one common bus. I plan to perform a power quality study to first determine what is causing the issues of momentary power loss that results in loss of weld strength. The issues happen sporadically and I have a few ideas as to what might be causing this but I wanted to get some unbiased opinions on the matter.

Key points

* There are several welders (dont know the KW or KVa).
* Frequency for which the issue occurs started at once per month. Now it is 5 times per week.
* All are on the same gear.
* PF is around 75% which suggests there is no power factor correction equipment that could be causing harmonic resonance.
* Loss of weld strength is only for 1 second or less (likely ms)

thanks in advance

 

[petersonra]

my guess would be they sometimes all turn on at the same time and this causes a voltage sag.

 

[ADub]

What is the model of the welders


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[aelectricalman]

What is the model of the welders



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the are all custom built.

 

[ADub]

the are all custom built.

Okay were they built to display a fault code like most of the ones I've seen? How has it been determined the welders are experiencing a momentary power loss, is it showing in the weld or some other way? As someone who works with industrial welding equipment every day I'm having trouble envisioning your scenario I'm sorry.


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