BOC Transtig 375 problems

[scottmk1]

I bought an old BOC Transtig 375 ages ago, and for one reason or another I've never used it until today.

Unfortunately it seems to have a problem where I have to have it set to max amps on AC to burn a 3.2mm rod on arc mode, never tried it on tig but the seller did tell me that it had some issue on tig mode but I cant remember the details now.

On DC it will hardly even strike an arc, regardless of how high I set the amps. Ive attached a pic of the front to show the settings for anyone familiar with these machines.

Any ideas?

 

[Tom O]

Could be the capacitors I had 1 out of 6 give smoke and replaced all of them on a 130 miller

 

[Dominic Muscat]

Hi, I have a Murex Transtig 375s and I think I have the same problem as you have. My electrician says there is a problem with one of the ICs on the main board. Did you manage to sort out your problem? Do you recommend someone who supplies the boards for these welders?
Thanks.

 

[scottmk1]

Hi, I think the Murex and BOC machines are different? I was off the understanding that the BOC didn't have any electronics

 

[eddie49]

Hi, I think the Murex and BOC machines are different? I was off the understanding that the BOC didn't have any electronics

That is correct, the older BOC machine has no PCBs in it. There are 4 transistors, but all the sequence control is by relays and the current regulation control uses a magnetic amplifier ( transformer ).

BOC became Murex and is now owned by ESAB. You could try to contact them, in case they still have parts for these very old machines.
https://www.esab.co.uk/gb/en/index.cfm
Maybe Westermans still have parts, or could arrange to have your PCB repaired:
www.westermans.com
The manual, including basic circuit diagram, is here:
http://murex-welding.co.uk/manuals/other/Instruction Manuals/Transtig ACDC275S-375S.pdf

 

[scottmk1]

Thanks for clearing that up @eddie49 do you have experience with these machines?

 

[eddie49]

Err, no, not really, I just have generic electronics knowledge. I do in fact own a Murex Transtig - bought before I knew how heavy it was or how many Megawatts it uses.

 

[eddie49]

Link to the current Murex Transtig 375s thread:
https://www.mig-welding.co.uk/forum/threads/murex-transtig-375s.96801/

 

[zeppelin builder]

i see you have it set on the lower range
try it flat out

is your power supply ok some of them dinsosaurs are single or split phase

 

[scottmk1]

I tried it on both ranges and even on max setting it would hardly burn a 3.2mm rod. Power supply is 3 phase and is ok