Miller Porta-Mig + PowCon 400SMT

[jackw19]

I'm working out the details to connect a Miller Porta-Mig wire feeder to a PowCon 400SMT. This looks pretty straightforward, finding (and paying for) the right Amphenol parts being the biggest part of the problem.

There's one thing, however, that concerns me. The PowCon manual says:

FOR WIREFEEDERS WHICH RETURN A 115 VAC SIGNAL TO THE POWER SOURCE FOR CONTACTOR CLOSURE, A SINGLE POLE DOUBLE THROW RELAY MUST BE USED. A RELAY KIT FOR INSTALLATION INSIDE THE UNIT IS AVAILABLE FROM POWCON AS 250082-001.

And this is exactly the way the Porta-Mig works.

The manual's call-outs of the PowCon's 17-pin connector include:

B -- Control Board Common. Used with remote control devices.
E -- Contactor Input. Will energize the welding power source when a dry contact closes to pin B.

Now I’d never heard the expression “dry contact” before, but apparently it means you just connect pins E and B with no voltage to either one when the gun trigger is pulled. The thing that puzzles me is why they call out a SPDT relay—it seems like a relay with 115vac control and single pole NO load side would do the trick.

I’ve got a solid state relay that has 115vac control and NO 115vac load—but solid state relays are funny things. Maybe in order for it to work properly the load must actually have to be 115vac—which it surely isn’t. Will as SSR work here, or mabye a conventional relay is a better choice?

Thanks very much.

[soutthpaw]

I had a couple different miller feeders running from a 400smt..
I put a double pole double throw relay in place of the orignal relay and jus connected the 2 supply and trigger terminals from the powcon to one side of the DPDT relay. So all it was doing is closing the circuit without adding current.....
Which style plug is it. The one that has several straight rows or the one that looks like s circles one inside the other. They were both used on powcon 400smt machines. I have one machine of each style...

[jackw19]

The receptacle on my 400SMT has a circle of pins within a circle, or more accurately a pentagon within a circle.

[soutthpaw]

The receptacle on my 400SMT has a circle of pins within a circle, or more accurately a pentagon within a circle.

I got one of those amphnol plugs still in sealed pkg if u can't find one to order.

[ccawgc]

Most powcons have output when no feeders are connected to the remote plug. You have to short the two right pins together to turn off the welder output. Miller and lincoln welders need the switch to close (short) to allow them to turn on the output.
You will want to use a standard relay. wire the coil to be operated by the feeder. And the normally closed contact to the powcon. Arc Products is no longer selling parts for Powcons So you are on your own to keep it running. If you need more information on the powcon I may have some. Send me your e-mail and request by PM.

[soutthpaw]

I have the 400smt manual avsilable on my google drive if u need it

[jackw19]

Thanks very much for your replies, gentlemen.

I did manage to find a 17-pin connector. In case you ever need one, try Amphenol 97-3106A-20-29P -- it's not quite right in that you have to re-clock the insert from standard S to W position. But that turns out not to be hard to do. The standard version is available from Mouser, etc but I couldn't find a source for the W version. It's a little quiz.

Manuals for several PowCon models are available for free download through the generosity of Arcon Welding at their website http://www.arconweld.com/Powcon_Oper...on-manuals.htm.

The machine has remote switch on the front panel, and the manual is fairly explicit (as below0

B -- Control Board Common. Used with remote control devices.
E -- Contactor Input. Will energize the welding power source when a dry contact closes to pin B.

So I guess I'll set it to remote and check for voltage at the output terminals. Assuming there is none, I'll connect B to E and hopefully hear a satisfying clunk and get weld power.

Connecting the control side of the relay across the gas solenoid in the feeder seems like the obvious thing to do, although with post flow that might be a bit of a conflict. The Porta-Mig, however, ain't got no steenking post-flow.

[soutthpaw]

I not sure if u are saying u r satisfied with your solution and wiring connection or would u like me to pull up my manual and double check what u listed as I have done one years ago. I will also check the part number on my amphnol connecter if u want me too. Just ask.... The best solution I have found is running a VS suitcase for mig. I ran a 400smt with a 300avs feeder as my primary mig for over a year....
We ran my GoWeld of my Powcon 300sm at the last weldorama so hopefully will get that video up. It worked best in spray mode for thinner and its just a monster set on CC instead of CV. Till we popped Jlames' breaker.

[jackw19]

SouthPaw, that'd be really great if you'd have a look at your manual and review my plan one more time. I'm pretty sure I've got it right, but I'd really prefer not to blow out a board on the old girl through ignorance.

Would have been easier and likely cheaper counting time to have just found a PowCon feeder and plugged it in. The PowCon PDII feeder (same as Hobart 2400, I believe) would have been plug-and-spray.

A VS would be a great solution, too, but it just isn't in the budget.

Anyway the Porta-Mig is remarkably well preserved, and it seemed like a good idea at the time. Then I got into it and one thing lead to another. These old machines are sort of like pets, although arguably less warm and fuzzy.