Hi guys I've just bought a 2nd hand Lincoln powertec 305c but it doesnt have the polarity quick change under the hood neer the wire feed and they've discontinued the kits, I'm going to rig something up later but in the mean time am I right in thinking if I swap these two connections over I will change the polarity to DC electrode negative for flux core, connection 1 currently goes to the gun and 2 comes from the earth transformer
- Thread starter Jimmy88
- Start date
Hello and welcome to the Forum.
There is a circuit diagram of the 305c Pro on Page 145 of the manual here:
It shows that the rectifier has three AC inputs and two DC outputs.
The negative goes to the inductor, which has a choice of two Dinse sockets for the work return cable.
The positive goes to the MIG torch, for solid wire with gas, but via a current-measuring shunt.
If you swap the two output connections at the rectifier, the current measuring display will not work or will give a false reading. You can probably fix that by swapping the two thin cables that measure the small voltage developed across the shunt and send it to the digital display.
( As a 3-phase machine, this welder does not need output smoothing capacitors, so there is no risk of reversing the supply there.)
There is a circuit diagram of the 305c Pro on Page 145 of the manual here:
It shows that the rectifier has three AC inputs and two DC outputs.
The negative goes to the inductor, which has a choice of two Dinse sockets for the work return cable.
The positive goes to the MIG torch, for solid wire with gas, but via a current-measuring shunt.
If you swap the two output connections at the rectifier, the current measuring display will not work or will give a false reading. You can probably fix that by swapping the two thin cables that measure the small voltage developed across the shunt and send it to the digital display.
( As a 3-phase machine, this welder does not need output smoothing capacitors, so there is no risk of reversing the supply there.)
hotponyshoes
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- Somerset. Uk
If you don't use the inductance settings you could use one of those sockets for switching the polarity externally.
Or just fit an extra one if you have the space.
Or just fit an extra one if you have the space.
Just to clarify the good suggestion made by hotponyshoes - the "unused" inductance Dinse socket would be disconnected from the inductor and connected to the positive output from the rectifier and labelled "+ve" on the front panel. The inductance socket that you do normally use would remain, as "-ve". The input supply to the Eurotorch socket, instead of a permanent link to the rectifier positive output, would now be a short flexible cable with a male Dinse plug, routed out through the front panel. This can then be plugged into the +ve socket for solid wire with gas, or the -ve socket for fluxcore.
hotponyshoes
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- Somerset. Uk
Another way to do it would be to put dinse plugs/sockets inside the wire cupboard on the machine as you'll have to go in there anyway to swap wires.
Or single pole anderson connectors. I've not tried it but it might be possible to cut a normal anderson in half?
Connect the meter wires to the machine side of the connections and that should still work fine (I think?)
Or single pole anderson connectors. I've not tried it but it might be possible to cut a normal anderson in half?
Connect the meter wires to the machine side of the connections and that should still work fine (I think?)
