Cebora Turbo 130 circuit diagram

[BMWbiker]

Hi - got a BOC Migmaster 130 - AKA Cebora Turbo 130 - which I'm in the process of converting to Euro torch after accidentally breaking the original . . .

I've fitted the socket and wired it up and everything works so far. The last step is to add a solenoid-operated gas valve. I already have a suitable valve salvaged years ago from a gas tumble dryer which went belly-up but I'm struggling to know where to connect it into the electrics in the welder. It's a 240V coil so would need to be connected to somewhere that is normally off but energised on pulling the trigger, hence my need for a circuit diagram.

A Google search reveals diagrams for later models but not mine - so can anybody help please?

My other idea would be to connect a high resistance relay coil across the wire feed terminals and use the relay's contacts to switch the mains supply to the solenoid valve . . .

 

[Hutcho]

Does it have a contactor inside these - I can’t remember

 

[Hutcho]

I think they do - I would see what voltage is switching that contactor on a use the right valve for it - it’s the negative lead ( work return lead - goes to a metal prong - big plastic block ( contactor )

 

[RonA]

Cebora 130 Turbo mig circuit - Google Search

RonA

 

[Pete.]

The only one I can find is the pocket turbo 130 should be the first on the list here:

https://welding.cebora.it/en/assistance/items-out-of-production?b_start:int=266

 

[eddie49]

This Cebora MIG, also re-branded as BOC and Snap-on, is unique in that the contactor is in the high-current welder output circuit. As Hutcho said, the three sets of contacts are paralleled by a metal strip, to share the 130-Amp current across all of them.
The attached circuit diagram shows that the welding transformer and rectifier are always on. The torch trigger switch sends the DC welding output to the coil of the contactor, which then makes the circuit in the work return path ( negative ).
Off-load, the output ( open-circuit voltage, OCV ) probably varies from 15v to 32v, depending on the selected power setting. During welding, this voltage will drop, perhaps by one-third. I would guess that a 24-volt relay would work satisfactorily, so a 24v slave relay could be paralleled across the existing contactor coil, with it's contacts then enabling your mains-powered gas valve.

 

[BMWbiker]

Thanks for the replies, guys.

I've found the answer in an old thread on this forum which shows where the wires to the coil on the contactor are and I think I can use T-Tap connectors on those feed wires to supply the voltage to the solenoid:

 

[eddie49]

From the above copy of an earlier thread, I did not know that there are actually 4 sets of contacts, joined in parallel by a "4 pronged metal thing". If this is a standard 3-phase contactor, one of the four sets may be a lower-current "Auxiliary" contact. If so ( or if you tend to use the welder at low power settings anyway ), you could cut off this fourth prong from the upper and the lower paralleling bridges, and use the fourth contact pair directly as the switch for your gas valve, without needing a slave relay.

 

[BMWbiker]

Sorry I haven't been very active on this thread today but my daughter came to visit with my 3-year-old grand-daughter and it's been hectic to say the least!

I'll have a look at the machine when I get the chance and I'll get back with my findings!

 

[rikrobson]

there are more pictures from my original tread in this gallery

https://www.mig-welding.co.uk/forum/media/albums/boc-130-upgrades.375/

 

[BMWbiker]

there are more pictures from my original tread in this gallery

https://www.mig-welding.co.uk/forum/media/albums/boc-130-upgrades.375/

Thanks for posting this - very helpful! What voltage solenoid did you use on the gas valve please?