Wiring an older 220V Spot Welder.. Help!

[Keyblazer]

I'm in the USA/ California...
Bought an old Lenco Panel Spotter, and restoring it.
Its 220V Single Phase 60A.



The original molded on plug is like this, but has a pin that feel loose and has pulled back from the sheathing:


I cut it off, and will replace it with a NEMA 6-50 which is what my 220v supply is for my Compressor/Welder.

When I cut it off, I was surprised to find Black/White/RED wires.

A look inside the unit to see where they went was interesting...
Main feeed wire comes in from top right..

1/ White is GROUNDED to the chassis.
2/ Red goes to one 60a BUSS fuse
3/ Black Goes to the other 60A Buss fuse.


After talking to a buddy, he suggested it should be wired like this:


I already cleaned up that stray red wire!

I cut the original plug apart, and found on it, the red/black are transposed...

Anyone???

 

[wyliesdiesels]

Thats normal to see since equipment is old and old plug was a 10-50p which is 120/240v non-grounded.

Those are no longer allowed and normally would be replaced with a 14-50p for 120v/240v grounded or a 6-50p for 240v grounded equipment.

Can you post a pic of the nameplate as i suspect this equipment may need a bigger circuit since it has 60a fuses(that is IF the fuses are OEM spec'd size).

YOu wired the plug correctly. The red and black positions dont matter for single phase 240v. They can go either way/polarity doesnt matter

 

[teamextreme]

You have it wired correctly. Polarity of the black and red wires is not important.

 

[nsula_country]

Classic reason when people ask about a welding circuit to do a 50A from the beginning... That Harbor Freight MIG may only need a 20A, but one day something like this shows up. Never know what welder you may drag home later!

Looks clean for its age. Will probably weld as long as we all live.

You wired the 6-50 correctly.

Post more pics once you get it going.

CT

 

[Keyblazer]

Good stuff!

I actually have TWO of these...

This is my other one...


Face plate...
Info on top left..
Pic not clear but says "Fuse for 60A".



My 220v circuit is fusted 60a at the breaker, and the circuit was wired for it because my Compressor is 220v single phase 7.5hp.
I swap the plugs when I use my 220v stuff...

 

[nsula_country]

Good stuff!

I actually have TWO of these...

This is my other one...


Face plate...
Info on top left..
Pic not clear but says "Fuse for 60A".



My 220v circuit is fusted 60a at the breaker, and the circuit was wired for it because my Compressor is 220v single phase 7.5hp.
I swap the plugs when I use my 220v stuff...

Curious what plug your 7.5HP compressor has on it?

CT

 

[wyliesdiesels]

Good stuff!

I actually have TWO of these...

This is my other one...


Face plate...
Info on top left..
Pic not clear but says "Fuse for 60A".



My 220v circuit is fusted 60a at the breaker, and the circuit was wired for it because my Compressor is 220v single phase 7.5hp.
I swap the plugs when I use my 220v stuff...

Whoops.

That 7.5HP compressor, by code, CANNOT use a plug and outlet. It must be hardwired.

 

[Keyblazer]

Ok!
It’s been like that nearly 10 years.
I will work toward fixing that now I know.

The first Panel Spotter I got a couple of years back is the one pictured above. It worked great out of the day I got it, and invested in it by doing the upgraded front panel and electronics that gives better control and the ability to do stud welding for dents and spot shrinking too.
The new to me one that I’m working on. It’s actually older than my first one, by the serial number. Inside it’s very different.
Will post more pics later.

 

[wyliesdiesels]

For the 7.5HP motor you will need 50a wire which means #8 THwN in pipe or 6/2 NM-b.

A disconnect is required if not within sight of and further than 50' away from the breaker panel.

Does the compressor have a mag starter?

 

[Keyblazer]

The breaker is on the other wall of my garage within 20'.
I dont remember off the top of my head what wire was used, but it was done for the compressor plus some headroom.
I think it has a Mag starter...
Will confirm...

Most of this stuff is being covered on my Crazy thread, about "What I'm up to in my little garage..."

https://www.garagejournal.com/forum/showthread.php?t=403443

Anyway, here is a pic of the front panel of #1, after I upgraded it to the "CK-35" Conversion...
Shows the specs.



It came with the NEMA 6-50 Plug already.

Those that have not seen these before, they have "Two Guns", which look like this, meaning the do two spot welds at a time normally.
They were built for the body shop to spot weld replacement panels in place where maybe access to both side of the are is not available.



Here is what it did with barely "Half warp power".
2 layers of 20g steel on right and 3 layers seemed to be no problem.



Backside.


Then I put the "Stud Weld" tips on... One gun has the hollow tip stud holder, and the other a "Rotating ground".


Test...

 

[Keyblazer]

The breaker is on the other wall of my garage within 20'.
I dont remember off the top of my head what wire was used, but it was done for the compressor plus some headroom.
I think it has a Mag starter...
Will confirm...

Most of this stuff is being covered on my Crazy thread, about "What I'm up to in my little garage..."

https://www.garagejournal.com/forum/showthread.php?t=403443

Anyway, here is a pic of the front panel of #1, after I upgraded it to the "CK-35" Conversion...
Shows the specs.



It came with the NEMA 6-50 Plug already.

Those that have not seen these before, they have "Two Guns", which look like this, meaning the do two spot welds at a time normally.
They were built for the body shop to spot weld replacement panels in place where maybe access to both side of the are is not available.



Here is what it did with barely "Half warp power".
2 layers of 20g steel on right and 3 layers seemed to be no problem.



Backside.


Then I put the "Stud Weld" tips on... One gun has the hollow tip stud holder, and the other a "Rotating ground".


Test...

 

[nsula_country]

That spot welder is pretty cool! You do body work?

CT

 

[nsula_country]

That spot welder is pretty cool! I'd like to have one just to **** around with! Do you do body work? Sheetmetal work?

Sorry, double post...

CT

 

[Bert_]

Just because I feel like fueling the fire.

Lots fan/heaters made by farm fans (a large company that makes grain drying equipment) back in the 70's-80's came factory with range cords and a 10-50P. Many had airover duty motors rated as high as 12hp with FLA's in the mid 50's.

I would guess 80-90% of shops around here use the 10-50 for welders and large equipment.

I still wire 5-10hp motors with 10-50 plugs. Mainly because that's what all the customers equipment already uses. It's funny, several supply houses stock outdoor power outlets with a 10-50R (Midwest U050 is common) One with a 6-50 is special order

 

[sberry]

It says 60 fuses but I bet it would work dandy with 50 breaker.

 

[rburke65]

Looks to me as if you have too much heat by the looks of the discoloration of your metal.

 

[Keyblazer]

As per my thread, I'm learning sheet metal and bodywork...
I have a 1974 Alfa Spider under restoration, and something large, shiny and Aluminum to fix(see my sig).

The spot welder(#1) came along when I was looking at the cheapo HF unit and I didnt know squat about them...


I've not needed to turn it up beyond 50% on the timer/power setting and its more than done everything i've asked so far... or more.
I'm doubting it'll need more in my care, so 50a would prob be fine..

I did my first test on a real dent on the nose of the Alfa...



Stuck it good..



In fact too good... pulled a slug out!

 

[Keyblazer]

Looks to me as if you have too much heat by the looks of the discoloration of your metal.

That was on 20g steel with the timer set on #4... I turned it down to #3 for the Alfa and it was still too much by the look!

 

[Keyblazer]

Is this a Mag Starter?

 

[Bert_]

You bet

It's just a heavy duty switch that is turned on and off electrically. Similar to a relay in the automotive world. A starter also provides overload protection for the motor (the reset you see on the bottom).

 

[Keyblazer]

Got it!
Thanks!

 

[kabinenroller]

I have a Lenco spot welder similar to yours. I bought it used but it works like new. After a few practice spots I used it for a restoration project, the spot welds look exactly like the factory welds this car had.
I do notice that if I do a run of spots the cable grips get warm and I have to let them cool down, not a big deal because the cables get heavy and I need a break.
Between my tig, mig, and the Lenco I am able to do most any repair that comes along.

 

[Keyblazer]

Good stuff!
Not used mine in anger yet, but its coming...

 

[nsula_country]

Just because I feel like fueling the fire.

Lots fan/heaters made by farm fans (a large company that makes grain drying equipment) back in the 70's-80's came factory with range cords and a 10-50P. Many had airover duty motors rated as high as 12hp with FLA's in the mid 50's.

I would guess 80-90% of shops around here use the 10-50 for welders and large equipment.

I still wire 5-10hp motors with 10-50 plugs. Mainly because that's what all the customers equipment already uses. It's funny, several supply houses stock outdoor power outlets with a 10-50R (Midwest U050 is common) One with a 6-50 is special order

Bert,

I have heard you mention farm grain setups in past posts. I also have had experience here. My father has been a mechanical/electrical contractor for over 40 years. His specialty is grain handling equipment installation and service.

I also have seen common use of 6-50, 10-50, 14-50, 15-50, L14-30, and other variations used (not installed by us) on motors as large as 25 hp. Farm grain bin setups with a center pit still in service with 200 amp 3P 240D using cords and plugs from the 70's.

Not code, but used annually. Farmers are known to not be electricians!

CT

 

[Bert_]

Bert,

I have heard you mention farm grain setups in past posts. I also have had experience here. My father has been a mechanical/electrical contractor for over 40 years. His specialty is grain handling equipment installation and service.

I also have seen common use of 6-50, 10-50, 14-50, 15-50, L14-30, and other variations used (not installed by us) on motors as large as 25 hp. Farm grain bin setups with a center pit still in service with 200 amp 3P 240D using cords and plugs from the 70's.

Not code, but used annually. Farmers are known to not be electricians!

CT

It's mostly what I do during the summer months. Nothing huge like an elevator for the most part, usually farmer owned stuff.

Some of the stuff that is wired by farmers or wanna be electricans is comical. I should really take more pictures. I love looking at the code violation thread on another forum.

The 15hp fans I was referring to came with 10-50's from the FACTORY.

 

[nsula_country]

It's mostly what I do during the summer months. Nothing huge like an elevator for the most part, usually farmer owned stuff.

Some of the stuff that is wired by farmers or wanna be electricans is comical. I should really take more pictures. I love looking at the code violation thread on another forum.

The 15hp fans I was referring to came with 10-50's from the FACTORY.

I believe you about the fans, was legit for years. Now if someone uses a 10-50 on a 3-5 HP air compressor, there garage is going to implode!

We (when I was younger and worked for him) did small elevator sites and one Grain Co-Op elevator. The rest were farm bins. We did install several continuous flow dryers and several blower systems. Mostly GSI and Hutchison equipment. Some Sukup. Still have some ancient Reed-Joseph centrifugal fan/heaters running.

Been a long time since I worked on farm electrical. Past 15 years I have been from Industrial Electrician to Industrial Automation Engineer.

CT

 

[wazzabie]

Good stuff!

I actually have TWO of these...

Hi Keyblazer - I've got the same green Lenco Panel Spotter. Its very old and dusty. I cleaned it up some, changed out the plug and tried it out. It works. I'm going to play around with the settings on it and get some new tips for it.

Did you find that the conversion improves the performance of the welder?

 

[Keyblazer]

Hi, have not used it that much before or after to pass comment.
But I gather the conversion does two things:
1/ Gives better timer control of arc, and
2/ Allows you to use the up to date accessories.

This was me using the Quick Pull dent gun on the Lenco I converted.

 

[wazzabie]

My thoughts on the green Lenco. I did a destructive test on some sheet metal and was able to get a good plug. I had to clamp the metal with vise grips. That is under ideal use case. My complaint is that with the lenco i can't put any force into the weld. I'm thinking for a stronger weld I mig a spot weld. For factory look use lenco but it may not be as strong.

 

[Keyblazer]

Not gonna disagree with you on the "Clamp Force" issue.
I guess if you really wanted to be sure, you could use a finger clamp, like they make for holding mig or tig spot welds, but it would be time consuming.
Or something like this...
https://www.eastwood.com/pinch-weld...y9eiqz9SyzJ2ecexMvyUqqpps9WDFN9hoCv38QAvD_BwE

Either way, I think cranking up the timer would increase the penetration and "Sink" the spot in deeper.

 

[rburke65]

As per my thread, I'm learning sheet metal and bodywork...
I have a 1974 Alfa Spider under restoration, and something large, shiny and Aluminum to fix(see my sig).

The spot welder(#1) came along when I was looking at the cheapo HF unit and I didnt know squat about them...


I've not needed to turn it up beyond 50% on the timer/power setting and its more than done everything i've asked so far... or more.
I'm doubting it'll need more in my care, so 50a would prob be fine..

I did my first test on a real dent on the nose of the Alfa...



Stuck it good..



In fact too good... pulled a slug out!

If your weld “pulled” metal...or “pulled” the weld nugget, then it’s telling you that you have a good weld. Your weld is stronger than the metal. I was an electrician and worked in the Body Shop for GM for 30 years maintaining weld equipment and programing welding robots. The Heat dial on your unit is probably for “cycles per second”.....at how many cycles Per second...60 cycles....do you want to weld. Thicker takes longer obviously. You could start..?..12 CPS and adjust accordingly.

 

[kabinenroller]

I have a slightly newer model of Lenco spot welder, it makes very good welds once I dial in the correct time. There is no adjustment amps just a timer that is controlled by a knob on the welder. Yes you do have to have the material tight to each other to obtain a good weld, I really have to push on the stingers sometimes. If I do a number of spot welds consecutively the leads for the stingers will get very warm.
I have found the Lenco to be an invaluable tool in my shop.

 

[wazzabie]

I find the Lenco has more juice then my 220v Miller spot welder. For some places my Miller can't reach.

 

[rburke65]

How is pressure applied to the 2 electrodes?

 

[Keyblazer]

You just push the two “Guns” against the panel.
It is my understanding that they were originally designed for body repair from one side.
It’s maybe not an ideal setup, but, I think it would be pretty easy to rig up a clamping system that could squeeze the two electrodes together.
But that kind of negates the reason these Lenco units exist.

 

[wazzabie]

According to this training video hold time (pressure on the weld) is critical for a good weld.

 

[ClappedOutBport]

My 220v circuit is fusted 60a at the breaker, and the circuit was wired for it because my Compressor is 220v single phase 7.5hp.
I swap the plugs when I use my 220v stuff...

Funny how it was working fine til the GJ folks came along!

 

[nadogail]

Spot Welders are really simple technology, many homemade spot welders started life as microwave transformers.

 

[Keyblazer]

Good info Ya'll!

I hadn't posted these destruction test pics of my test piece, but I'm gonna say this beast works, and some!
For the record, this was THREE Layers of 20g steel.

 

[wazzabie]

Good info Ya'll!

I hadn't posted these destruction test pics of my test piece, but I'm gonna say this beast works, and some!
For the record, this was THREE Layers of 20g steel.

Keyblazer - Your nuggets looks good. I've been testing my green Lenco Panel Spotter plugged into 50amps vs my 220v 30mp Miller manual clamping spot welder. I'm testing on a spare factory 18 guage fender I cut up for testing. I've ground of the paint and sprayed copper weld Tru primer for the tests. I read online that for fusing 18 guage sheet metal panels the nugget diameter should be 7/32in. At best with the Miller yields 5/32in nuggets in my destructive tests. The Lenco however produces the nugget just like factory in size. I use vise grip clamps adjacent on both sides were I weld. So there are some trade offs. Smaller nugget w/ clamp force vs. larger nugget vs no clamp force. I think however I'm going to use my Lenco because the nugget is like factory. I want to replicate factory as close as possible