1 phase Vs 3 phase Hot hot hot!

[Torq]

Hi Guys,

for the past few weeks I've been doing a TIG welding course and am finally getting the hang of it! I've been mainly welding 4mm stainless plate using a big lincoln 3 phase TIG plant but last night I brought in my little Telwin Tecnica 111 single phase inverter as it's what I'll be using at home.

Obviously there are differences, one is 4 step the other is scratch start but the biggest difference I've found is heat! The lincoln is set at 80a and the Telwin at 40a for the same weld using the same tungsten, shroud and gas flow. But the telwin is heating up the metal to far higher temps than the lincoln. So much so that I've a blister on the side of my little finger from heat that passed through my gloves.

Why is one so much hotter than the other, even though it is set to 1/2 the current??

Thanks,
Torq

 

[Jim_gsxr1000]

May seem daft but are the torch and the earth in the corect position, i asume its on steel DC ?

 

[Torq]

No such thing as a daft question in troubleshooting, somethimes the most obvious can be over looked. Both were set to have the earth on +ve and both are DC.

T

 

[shenion]

It would be more likely:

1. One is not very accurate in the settings.
2. Inverter continuous DC vs transformer rectified AC. That will effect the arc focus.
3. A dial setting assumes the operator uses the same arc length and tungsten as the dial assumes. Transformer machines tend to not have a true constant current. A display would likely actually measure the current.

Note, if the Lincoln is a transformer machine that does AC it will be a single phase machine. It just may be operating on 415V.