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Electronics => Repair => Topic started by: leftek on March 04, 2017, 06:25:05 pm

Title: Inverter stick welder
Post by: leftek on March 04, 2017, 06:25:05 pm

Hello, i have an damage inverter welding machine and would like a opinion for repair it.
The machine have normal output voltage when it is in idle status without load.
When i connect the outputs (+/-) via a small cable, spark it a little and just cut down the output to 0V and i think that the problem is on IGBT's K30H603 or on driving circuit of them.
But the spark is stronger when i adjust the potentiometer.
The question is : may the problem is to driving circuit of IGBT's while the potentiometer affect on the spark?

Title: Re: Inverter stick welder
Post by: strawberry on March 04, 2017, 07:10:22 pm

What device model, pictures, schematics, topology? Does it have Lift start? Then it is not starting main power.
Propably current feedback is not working and main power is cut off by short circuit protection.

Title: Re: Inverter stick welder
Post by: Armadillo on March 04, 2017, 07:43:23 pm

Sounds like the potentiometer is the problem, loose or dirty contacts. Maybe you should use a contact cleaner like Deoxit to clean the potentiometer first.

Title: Re: Inverter stick welder
Post by: leftek on March 05, 2017, 12:32:14 pm

Thank you for your reply "strawberry" and "Armadillo". Finally the only problem was the welding cables and torch and its ok now.  |O
The mention for "Lift start" from "strawberry" had help me. :)
To help anybody in the future : "It's correct the response of machine to cut down the output voltage when bridge the outputs."
This operation avoid the stick to adhere.