Bought a new to me Airco Dip/Stick 160 multiprocess welder

[Hondacivic247]

The capacitors are screw top style if there taller I got extra room. What would happen if I put in a 20000mfd 50vdc capacitors, as in all 5? Would it give a better arc characteristics?

[Aeronca41]

Generally, adding capacitance tends to smooth out/stabilize any power supply. However, the guys who designed this welder were not amateurs, and chose the capacitance values for good reason. I would assume the choice was tuned to play well with the value of the welder's inductor, and also in light of inrush current when the machine is first turned on. There are also other potential engineering issues to consider. I guess if it were mine, and I found some slightly larger (say 11 or 12K MFD) capacitors at a great price I might go with bigger ones, but I don't think I would double them to 20K. Going to a higher (but not lower) voltage rating as H80N said is fine. I guess you would need a welder design engineer for a "real" answer.

[Hondacivic247]

We tested them at work and got open loop on 2 which we assume makes them no good.

[Aeronca41]

Looks like it's time for some new caps.

[H80N]

Generally, adding capacitance tends to smooth out/stabilize any power supply. However, the guys who designed this welder were not amateurs, and chose the capacitance values for good reason. I would assume the choice was tuned to play well with the value of the welder's inductor, and also in light of inrush current when the machine is first turned on. There are also other potential engineering issues to consider. I guess if it were mine, and I found some slightly larger (say 11 or 12K MFD) capacitors at a great price I might go with bigger ones, but I don't think I would double them to 20K. Going to a higher (but not lower) voltage rating as H80N said is fine. I guess you would need a welder design engineer for a "real" answer.

I agree.... but your biggest problem may not be finding the capacitor values to add up to the "correct number as designed"....
it may be finding enough "fresh" capacitors in the original form factor to bolt right up to the bus bars without mods
Those large "Root Beer Can" style packages were the norm in the 1970s.... where they were popular in linear computer power supplies
.... But....technology has marched on and capacitors have become more efficient in smaller packages... so you may have to modify the connection method...

[Aeronca41]

That triggers an idea-if you can find modern capacitors at a reasonable price, it doesn't matter how many you use in parallel to get to the total number of microfarads. Can't tell for sure but it looks like you have three caps hooked to those bus bars? 10K each = 30K MFD, or however many there are. So, if you can find two 15K, or a 10K and a 20K, that will also work---or more smaller ones (six 5K?) so long as they add up to 30K and have a voltage rating at least as large as the current ones. Caveat-those are hooked together with fat bus bars for a reason-there are some very high instantaneous currents in this circuit while welding, potentially far above your set welding current, as the caps charge and discharge. If you use diff caps with diff mounting methods, fab up some equally robust bus bars to hook 'em up, and be sure they can't move around and short out-everything must be firmly bolted in place. Hang in there. It's great to see these old machines brought back to life.

[Hondacivic247]

Klein is saying oL is for overload range exceeded so I'm not sure how I'm suppose to tske that with these caps

[Aeronca41]

Just saw that there are 5 caps in your machine. So you need 50K MFD if they are all in parallel, which I assume they are.

[Aeronca41]

Klein is saying oL is for overload range exceeded so I'm not sure how I'm suppose to tske that with these caps

Check the manual on your meter. Either it can't read a cap that large, or the cap is open.

[Hondacivic247]

There's a total of 5 of these in the welder 3 on one side and 2 on the other which I took out. So I would need to find a total of 50k mf with 50vdc

[Hondacivic247]

The guy I work with also gave me a number to a capacitor specialist who is looking into finding new ones for me along with decoding them sense it doesn't list a tolerance window like newer ones have

[Hondacivic247]

Will these work there mallory made in the USA just unsure if the heat range is correct

[Hondacivic247]

http://www.tedss.com/CGS103U050V5L3PH/?gclid=Cj0KEQjwmpW6BRCf5sXp59_U_ssBEiQAGCV9Gsq9xSjum_uMn0DdFfMqt7UPCoHjzTZRBqtJOrN1waEaAk588P8HAQ

[H80N]

That triggers an idea-if you can find modern capacitors at a reasonable price, it doesn't matter how many you use in parallel to get to the total number of microfarads. Can't tell for sure but it looks like you have three caps hooked to those bus bars? 10K each = 30K MFD, or however many there are. So, if you can find two 15K, or a 10K and a 20K, that will also work---or more smaller ones (six 5K?) so long as they add up to 30K and have a voltage rating at least as large as the current ones. Caveat-those are hooked together with fat bus bars for a reason-there are some very high instantaneous currents in this circuit while welding, potentially far above your set welding current, as the caps charge and discharge. If you use diff caps with diff mounting methods, fab up some equally robust bus bars to hook 'em up, and be sure they can't move around and short out-everything must be firmly bolted in place. Hang in there. It's great to see these old machines brought back to life.

+1... on that.......

Modern is good... likely many old ones probably well past their fresh date and as marginal as the ones you are pulling..

Many used surplus caps probably having escaped the scrap by being stripped from some vintage.... PDP11..Vax....System3... DG-Eclipse... PE-8-32... or some other 70s Mini Computer...
(Dated Myself...)

Regardless of mounting style check the Date Code...

[Hondacivic247]

Will these mallory work? Look to get the same specs

capacitance: 10,000 uf
voltage: 50 vdc
tolerance: -10%+75%
temperature: 85
lead type: screw
lead style: high post
package: bulk
item per pack: 1
Diameter: 2 in, Height: 5.625 in