300d Remote Rheostat Wiring

[feetfats]

Does anyone have a wire diagram for my classic 3d remote?

Something is funny and I am trying to track it down.

There is no toggle switch for my remote so I think that may be part of the problem, but I am unsure about where to hook it up.

Thanks

[slowhand]

In the old day, I'm talking late 70's - early 80's here, we used to just put a piece of broken clear-glass under the panel rheostat to lift it off the little wires (which actually just took it out of the circuit), tie-on extension wires to the 2 posts on that rheostat and run that out to our remote box. In those primitive days a remote box was sometimes an normal electrical box with a lid. :laugh:

Some, including myself, just took the rheostat out of the machine, tied-on wires to the 2 existing there and ran those to a pigtail with a plug on it, connected a 100' extension cord, then built a small metal box to mount the rheostat in and called it "modern". :laugh:

Later came the day of the SPDT switch. You could now leave the original rheostat in the machine and also have a remote. One of the wires to the rheostat is ground (common) so you can leave that one connected, but we took the original "other wire" off the rheostat and ran it into the center of our dual position switch. One side went to the original rheostat, and the other to our pigtail/plug cord and 100' cord. We could flip the switch and go to local or remote. Now that was modern.

Lincoln incorporated the twist lock receptacle sometime ago. Its a hard to figure out deal if you're trying to wire your own homemade remote box to. If you can find the grinder wires (the 120v) then the others are easier to figure out what they are. The schematic of the machine can help and if you're an electrical engineer that will help a lot. :laugh:

Hope this helps
Good luck

[feetfats]

The schematic of the machine can help and if you're an electrical engineer that will help a lot. :laugh:
Hope this helps
Good luck

That would help lol.

The schematics on the doors are no longer readable.
I have 110 already and the remote works when I set the rheostat on the machine to low. But it doesn't weld as well as when I un-plug the remote and just use the panel control. I put a new rheostat in my remote as it had the wrong one. That helped a lot but it still isn't right. I'm thinking it needs a toggle switch.

I've had my head under my helmet too much lately to get a chance to mess with it.

[slowhand]

That would help lol.

the remote works when I set the rheostat on the machine to low

If you have things wired right - - it shouldn't matter what the panel mounted rheostat is setting on. You don't want it in the circuit too when you're using a remote. If it is - then you can do the old clear-glass trick and see if that changes things.

The reason we set our panel mounted rheostat to its lowest point is for two reasons (maybe three).
1st. So we'll know if the machine is welding OK then "we must have the remote/local switch set correctly".
2nd. If somebody "flips your toggle" without you knowing it, or it goes bonkers on you, and you somehow wind up on "local" then it probably won't weld with it set to its lowest setting. Then #1 reason will also work for you.
3rd. It looks cool set that way. :laugh:

Good luck

[feetfats]

I bought a 50amp toggle switch. Should that be big enough.

Why does the rheostat have three wire connection points?
Is just so you can control what direction is increase or decrease?

[slowhand]

Exactly. Its just a big-potentiometer and they also have 3 posts. We use the two that makes the dial backwards. :laugh:

50 amp is big, but it'll work. The current is somewhere around 6 amps @ 120 volts DC. Maybe more - maybe less. Like I said I've never metered it (but should have).

Don't flip the toggle while the engine is running or you'll arc your toggle. That is a common practice and hasn't changed over the years. I've used a lot of 20 amp auto parts toggles in the past and they were big enough.

Good luck

[feetfats]

Ok, thanks slowhand.

I have the switch in and it seems to be working fine.