Page 1 of 1

Old Machine AC Hi and Lo Range Century

Posted: Thu Dec 01, 2022 10:49 am
by thomastipton
I have an old Ac machine that has a hi range and low range. My question is there a electrical difference in the two ranges and what purpose does it serve.

Re: Old Machine AC Hi and Lo Range Century

Posted: Thu Dec 01, 2022 9:48 pm
by Jack Ryan
thomastipton wrote: Thu Dec 01, 2022 10:49 am I have an old Ac machine that has a hi range and low range. My question is there a electrical difference in the two ranges and what purpose does it serve.
I assume you have an ARC (Stick) welder.

High and low are generally two taps on the secondary of the transformer. Either can be used to weld but one has a slightly higher voltage (and slightly lower maximum welding current) that helps with some electrodes.

Re: Old Machine AC Hi and Lo Range Century

Posted: Thu Dec 01, 2022 10:25 pm
by thomastipton
Thanks for the information . What rods would work with the higher voltage and lower current. I am use to welding with a dc welder and trying to relearn on the old ac machine. Thanks Tommy

Re: Old Machine AC Hi and Lo Range Century

Posted: Fri Dec 02, 2022 12:44 am
by Jack Ryan
thomastipton wrote: Thu Dec 01, 2022 10:25 pm Thanks for the information . What rods would work with the higher voltage and lower current. I am use to welding with a dc welder and trying to relearn on the old ac machine. Thanks Tommy
The terminals are not consistently named - sometimes "High" means high current, sometimes it means high voltage. Sometimes they are not called High and Low at all. Higher voltage often gives a more stable arc. Try both with 6011 and 7018 - they should help you decide.

Changing the OCV changes the slope and changing the slope allows different levels of control over penetration (current) with arc length. It's a long time since I've used an AC ARC welder with High/Low terminals so I'm a bit out of touch.

There might be something you can filter out of this:
https://weldingweb.com/vbb/threads/7130 ... tage/page2

Jack

Re: Old Machine AC Hi and Lo Range Century

Posted: Fri Dec 02, 2022 9:25 am
by thomastipton
Jack, I appreciate your information. 6011 and 6013 rods seem to burn good on both Hi and Lo. 7018 is another story.
I picked up so cheap 7018 rods on Amazon and they burn good on my DC welder but I have trouble initiating an arc on this AC welder. 7018 Lincoln Electric seem to burn fine. I guess I need to run some test between the two settings.

Thanks Tommy