Sip Tig 160 AC/DC problem

[Weldtech]

Hello everybody

I have got a Sip Tig 160 AC/DC tig which is driving me crazy. The problem is that the current level although decreased to minimum is still too powerful cannot be decreased any more. I tried to connect the set as 230V instead of 400V but the problem is still the same.

I replaced almost every part of the electronic board and checked the thyristors but they are ok. Also, the transformer is making a loud hum during welding.

Anybody has got this problem or maybe has got a schematic of the set please?

Thanks.

 

[jonathannc]

Hi does the transformer hum loud ..? probably cored. have the same tig unit, scored secondhand and hummed away, check out the winding and irons, high chance someone had been in before to tighten or bodge.

the power level increased bit by bit, one day it blew a winding, causing a few problems elsewhere. don't have a circuit diagram, backward engineered the unit, even the Hf unit.

cost of new transformer from sip was high 2/3 of new machine, shame as the ac/dc 160 tig worked very well nice low power range,, missed it so ended up rewinding the transformer myself.. well worth doing works great for light alloy sheet etc, weld coke cans together what more can one say.