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Welding positioner help

KnightFab

Plastic
Joined
May 6, 2022
Location
Vail, CO USA
Hi all,

I recently picked up this Atlas model 200 welding positioner. Got it from a local welder who had shut down his shop and was getting rid of most of his surplus machinery. He told me he's been using it for over 30 years and he picked it up used at auction prior to that. All of the functions work great but I decided to tear it apart to clean it up and repaint it for another lifetime of use. Upon opening the case I was greeted with a rats nest of wires, most having been previously repaired and a few that had been burnt though. Ive begun replacing everything with new wire and connections but am unsure about how or even if the motor was grounded. I have the foot pedal and power cable both grounded now but looking at the wiring diagram for the motor (Dayton 2Z799C) it appears it never had a ground wire. Its a 4 wire motor that goes to a forward/reverse switch and a speed controller (KBVC-14). There is a fuse in the system as well going from power cable to the speed controller which then goes to the foot pedal. Is the motor grounded elsewhere in the system or should there be somewhere I am missing to connect another ground cable? Any input would be greatly appreciated! Id love to put this guy to use but don't need any shocks. The wiring is a bit less straight forward than most of what I've done in the past, especially considering the possibility of welding current interfering with things. Thanks in advance.

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cyanidekid

Titanium
Joined
Jun 4, 2016
Location
Brooklyn NYC
if the chassis is grounded, and the motor is secured to it without isolation (metal to metal connection), its grounded. particularly since its a gearmotor with a cast gearbox. it is (I think?) best practice to have a ground jumper to the motor housing as well, in case the motor comes loose from the chassis.

adding additional ground jumpers is easy, and can't hurt anything, what are you worried about? go nuts.
 

Garwood

Diamond
Joined
Oct 10, 2009
Location
Oregon
What kind of motor? 4 wires suggests series wound DC.

I would not worry about adding grounds to anything. It worked for how many decades?
 

boslab

Titanium
Joined
Jan 6, 2007
Location
wales.uk
Job for a meter across plug to chassis plus spike the wires on by one, a piercing meter lead is handy, mines fluke, and sharp, useful.
The Earth goes somewhere on the chassis to an Earth tab normally. It’s handy if you have an elcb on your supply board ( Earth leakage) it certainly doesn’t look double insulated!
Mark
 

Nerdlinger

Stainless
Joined
Aug 10, 2013
Location
Chicago, IL
I’m probably wrong but won’t it effectively be grounded via the ground clamp on your workpiece during welding? Just a thought…
 

boslab

Titanium
Joined
Jan 6, 2007
Location
wales.uk
Probably would but there may be conditions that could give you a bite, I’d Earth it myself ( we have to over here but it’s all to protect people, and having been electrocuted several times in my life I would prefer not to be “ walking the mile”
Mark
 

dalmatiangirl61

Titanium
Joined
Jan 31, 2011
Location
BFE Nevada/San Marcos Tx

Rob F.

Diamond
Joined
Aug 5, 2012
Location
California, Central Coast
"Work" and machine ground are qty (2) different things.

Funny story of me doing some light tig work on ss tube in a rotator 20 or so yrs ago. We had this little pile of stainless fittings to weld onto short pieces of tube to do in the rotator. We set up the rotator on a welding bench in the clients facility, the tig machine was in the welding trailer backed up to the bench, ac-dc pow con if I remember, XMT did not have gas solenoid so did not see much tig use. Anyway after a bunch of the parts are welded it starts to smell like burning plastic, so look around a bit to see what the hot part rolled on to to stink and there is nothing, keep looking and notice the power cord to the minarik dc speed control box looks kid of shiney. It was HOT and it looked like it was melting, from the inside as you could see a wire inside was causing the casing to melt, along the length of the cord where the wire was. WTF??:eek: Well after some more looking and checking it turns out the ground lead for the welder had got un hooked from the table leg and was far away from anything metal. Maybe we never even hooked it up in the first place, just rolled it out. That did not slow us down from welding, imagine that welding without the ground lead hooked up, still thinking WTF, how is this even possible? Some more thinking and the electrical ground and the welding ground were the same ground in the welding machine and the welding current went up the 3 phase power cord, into the panel and down the 120v ground wire to the outlet we had the rotator plugged into, then down the power cord where it connected to the alum box the speed control was in, by sitting on welding table that finished the ground path to the weld. No idea how many hundreds of feet of wire that ground went through.
It was vey small welds welding for maybe 20 minutes or so before smelled the casing starting to melt. Rotator was fine, still is actually, I have it now, I think we put a new cord on it though.
 

ratbldr427

Stainless
Joined
Mar 21, 2006
Location
jacksonville,fl.
Mine is an Aircrafter, Made by Martin co in California. The top switches are fwd-rev and high and low speed. Has the back gas port like yours. Has the foot pedal control and will not run until the pedal is actuated. See who made yours. I got the manual on line for mine and it has the wire diagrams. As I said it looks just like yours. It also has a ground lug that I put an extended 12'"cable with a brass block on the end to clamp the ground cable to.
 








 
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