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eaklebe
10-01-2011, 07:22 PM
I just acquired an Idealarc 250 Code 7279-C Serial No. AC-368154 Model 250-250, This was built in 1972 and the cables leave much to be desired. Can anyone tell me if this machine and the "power factor" capacitors? I looked at the Lincoln web site and found the manual, but it is difficult to interpret: the power factor capacitors at marked as #24 on the parts diagram, but it looks to me that they are at the front panel of the machine. I took the cover off and there are two large rectangular capacitors on a partition in the back part of the machine, one on each side of the fan. Are these the power factor capacitors?

Also, since I most likely will never exceed 200 amp welding current, what size wire would be best for the ground and stick holder?

Thanks

snoeproe
10-01-2011, 07:41 PM
The C in your code number indicates your unit has the power factor caps on it.
Your weld leads depend on how far you want to run from the unit.

papaharley03
10-01-2011, 08:31 PM
I took the cover off and there are two large rectangular capacitors on a partition in the back part of the machine, one on each side of the fan. Are these the power factor capacitors?


That would be them. And, as snoeproe mentioned, the C in your code means they were factory installed.

These are great machines, you'll enjoy it.

Papa

eaklebe
10-02-2011, 01:10 PM
Thanks for the replies. It's probably overkill for me, but I got a pretty good price (I think). One question: I don't know if this is the same process, but this is true with old radios: if the unit has been sitting unused for a long time, the advice with radios is to "reform" the capacitors by NOT applying full power to them , but by applying less than full power over the course of time -- the contention is that applying full power at once will burst the capacitors. Would this also be true of this welder?

farmall
10-02-2011, 07:04 PM
Being kind to caps cannot hurt. I let my new/old Miller 340 sit turned on for a few hours, then only did light welding with it for a couple of days.

I've not bothered to look into the science behind this precaution since it cost nothing to observe it, and old amateur radio folks who told me about it have far more relevant experience.

Bluewelders
10-02-2011, 07:24 PM
Power factor capacitors are oil type,they don't need reformed.

Rick V
10-02-2011, 08:07 PM
I suggest you read the owner's manual... the modern Idealarc sucks up almost 4X as much power at idle (23 amps vs 6 amps) with those capacitors connected for a gain of only 17% less power consumption (69 amps vs 83 amps) when welding at full bore. So if you'll be idling 90% of the time, you might just want to disconnect those puppies.
e.g At idle - doing nothing...
Without Caps, Power used = 230 volts x 6 amps = 1380 watts
With Caps, Power used = 230 volts x 23 amps = 5290 watt... almost like four 1500 watt heaters!
Your choice.:laugh:

ccawgc
10-02-2011, 08:23 PM
Just tun the welder on, weld up your project and turn it off. Don't let set there with just the fan running.

snoeproe
10-02-2011, 09:31 PM
I have only heard the info Rick just posted on these online forums. I would verify this info from Lincoln themselves before you worry about removing the caps from the welder yourself or getting rid of the machine just because the caps are on it.
If the info Rick just posted is indeed true, I wouldn't worry too much about it due to the fact that these machines are 100% duty cycle at 140 amps and less. So, you can basically run a 1/8 rod by turning the machine on, burn the 1/8 rod (or several 1/8 rods), turn the machine off as soon as your done welding and you have no worries of exceeding the duty cycle and over heating the machine.
Just turn the welder on, burn the rod(s) and turn the welder off, No worries and no need to leave the machine on so the fan continues to run to prevent exceeding the duty cycle.

Edit: I just downloaded a manual for your welder. Ricks info he posted for the "current" idealarc is correct. The mistake Rick made though was thinking your machine is the same specs as the new idealarcs.Your machine is not spec'd the same as the current 250 idealarcs. Your 1972 machine has the same specs as mine (1992 model). At full output of 250 amps dc your machine draws 70 amps on 230v without the caps, not 86 amps like Rick stated. With the caps installed at 250 amps dc your machine draws 50 amps on 230v, not 69 amps like Rick stated.

norite
10-03-2011, 01:28 AM
Just tun the welder on, weld up your project and turn it off. Don't let set there with just the fan running.

I always let my welder cool down, idle with the fan running. Time depending on how hot and how long I used it. Excessive heat is about the only thing that can kill a welder like this.

If you download the manual, it will recommend the proper cable sizes depending on length you are using. I used 2/0 cable with mine, just because that was what I had, you could go smaller.

Rick V
10-03-2011, 10:57 AM
...Edit: I just downloaded a manual for your welder. Ricks info he posted for the "current" idealarc is correct. The mistake Rick made though was thinking your machine is the same specs as the new idealarcs.Your machine is not spec'd the same as the current 250 idealarcs. Your 1972 machine has the same specs as mine (1992 model). At full output of 250 amps dc your machine draws 70 amps on 230v without the caps, not 86 amps like Rick stated. With the caps installed at 250 amps dc your machine draws 50 amps on 230v, not 69 amps like Rick stated.
Me... make a mistake? :laugh: All the Time!

Snoeproe, the old manual is correct as far as it goes (full power figures 70 and 50 amps) but it doesn't go far enough.
It's darn misleading because, unlike the modern manual, it does not provide the power figures (amperages) at idle. Thus after reading that old manual, it sure looks like having having power factor correction capacitors is the way to go... 29% less power used to weld... when in fact your machine may be costing you a fortune because of a major (~400%) increase in idle power consumption. IMO, THAT'S MISLEADING INFORMATION!
There's two sides to every coin; just because it's not stated in the old manual, does not mean it's not happening. Best be aware of it.

The idea of turning the welder on/off for each rod is... not a good idea.
That's likely the best way to burn up your welder; how is the 'not running fan' supposed to get rid of heat from the welder internals? :gunsfirin I mean - duh? what's the fan for?
I believe there was a recent post by a fellow whose Lincoln AC-225-s overheated and quit because he was doing that - turning the welder on/off for each rod.

snoeproe
10-03-2011, 09:57 PM
Rick.
Did you read my info I posted about the duty cycle?
At 140 amps or less, these machines are 100% duty cycle.
That means you have no worries about overheating anything when your running at 140 amps or less.
So, after running a 1/8 7018 rod at 125 amps then turning the machine off when your done welding will not harm the machine at all. 100% duty cycle, remember?
Now, weld at higher currents than 140 amps then yes, the fan needs to run to cool the machine.
The AC 225 is a toy compared to a 250 Idealarc. Not even in the same class. Your comparing a entry level buzzbox to a heavy duty industrial machine. The two machines have VERY different power and duty cycle ratings.
You dont see AC 225 welders used in industrial construction. You do see 250 idealarcs used in heavy industry all the time.

Rick V
10-04-2011, 12:16 AM
The AC 225 is a toy compared to a 250 Idealarc. Not even in the same class. Your comparing a entry level buzzbox to a heavy duty industrial machine.
What are you talking about? When did I mention an AC 225? When did I do a comparison? Are we cross-threaded here?

Staying on topic of this thread, the Lincoln Idealarc...
Regarding you statement, "At 140 amps or less, these machines are 100% duty cycle".
Yes that's what the manual says... assuming the fan is running as I am sure Lincoln did.
Then, you should be able to run electrode after electrode without pause.

Turning the machine on, run an electrode, turn the machine off... and repeat this sequence several times.... I doubt this is Lincoln's recommended practice or even practical.

My point is that the power factor capacitors make little sense if the Idealarc welder is going to be sitting there at idle most of the time... that's the usual situation. Then, it's consuming almost 4,000 watts more power because it's got those power ffactor capacitors connected.

snoeproe
10-04-2011, 07:43 AM
Me... make a mistake? :laugh: All the Time!

The idea of turning the welder on/off for each rod is... not a good idea.
That's likely the best way to burn up your welder; how is the 'not running fan' supposed to get rid of heat from the welder internals? :gunsfirin I mean - duh? what's the fan for?
I believe there was a recent post by a fellow whose Lincoln AC-225-s overheated and quit because he was doing that - turning the welder on/off for each rod.

Was this not a reference to an AC 225? I must be loosing it, then, lol.
Rick, you have a lot of posts. Over 1300 infact.
What you indicated to us all in your above post is that you dont understand the concept of duty cycle with a welding powersource.. Thats a lot of posts for a fellow who appears to not understand the duty cycle concept.
The AC 225 is not a 100% duty cycle machine

Rick V
10-04-2011, 08:43 AM
OK, you are right... jeez, I did mention that other post on the AC 225 - you got me! Maybe I'm the one that's losing it? :laugh:

As to duty cycle, I do believe I understand it; I've got math charts for my machines.
Amps at wanted duty cycle = Max amps at known duty cycle x Square root of (known duty cycle/wanted duty cycle)
e.g. 1: A Lincoln Idealarc rated at 250 amps out at 30% duty cycle can do:
100% duty cycle = 250 amps x sqrt (30/100) = 250 x 0.548 = 137 amps
80% duty cycle = 250 amps x sqrt(30/80) = 250 x 0.612 = 153 amps
50% duty cycle = 250 amps x sqrt(30/50) = 250 x 0.775 = 194 amps

e.g. 2: A Lincoln AC 225 rated at 225 amps out at 20% duty cxycles can do:
100% duty cycle = 225 amps x sqrt (20/100) = 225 x 0.447 = 100 amps
80% duty cycle = 225 amps x sqrt(20/80) = 225 x 0.5 = 113 amps
50% duty cycle = 225 amps x sqrt(20/50) = 225 x 0.632 = 142 amps
30% duty cycle = 225 amps x sqrt(20/30) = 225 x 0.816 = 184 amps

Published welder duty cycles are based upon the machine being used normally - with the fan running. Turning a machine on, run a rod, turn the machine off - all bets are off! The heat put into the internal components of ther welder during welding has little chance to escape since the fan was turned off right after running the rod. Keep that up and the heat will build up and not have the normal chance to escape. I suspect too that the life of the on/off switch will be severly reduced being toggled on/off for every rod. This procedure is not logical.

eaklebe
10-04-2011, 11:19 AM
Thanks for confirming that I hadn't read that spec incorrectly. It has great utility for what wiring up my garage is gonna cost me.... Lot cheaper for a 50 amp circuit than a 70 amp circuit (esp since I'd have to install a new sub-panel connection).









I have only heard the info Rick just posted on these online forums. I would verify this info from Lincoln themselves before you worry about removing the caps from the welder yourself or getting rid of the machine just because the caps are on it.
If the info Rick just posted is indeed true, I wouldn't worry too much about it due to the fact that these machines are 100% duty cycle at 140 amps and less. So, you can basically run a 1/8 rod by turning the machine on, burn the 1/8 rod (or several 1/8 rods), turn the machine off as soon as your done welding and you have no worries of exceeding the duty cycle and over heating the machine.
Just turn the welder on, burn the rod(s) and turn the welder off, No worries and no need to leave the machine on so the fan continues to run to prevent exceeding the duty cycle.

Edit: I just downloaded a manual for your welder. Ricks info he posted for the "current" idealarc is correct. The mistake Rick made though was thinking your machine is the same specs as the new idealarcs.Your machine is not spec'd the same as the current 250 idealarcs. Your 1972 machine has the same specs as mine (1992 model). At full output of 250 amps dc your machine draws 70 amps on 230v without the caps, not 86 amps like Rick stated. With the caps installed at 250 amps dc your machine draws 50 amps on 230v, not 69 amps like Rick stated.

eaklebe
10-04-2011, 11:39 AM
Could you point me to some information on this?
Everything I know about capacitors in electronics tells me that once a capacitor is charged up, it no longer draws power - with the poss exception for some very minor leakage. My understanding is that power factor capacitors buffer the large surge current at the start of operation of any machine and then feed that stored current back into the machine operation subsequently.




[snipped]
Snoeproe, the old manual is correct as far as it goes (full power figures 70 and 50 amps) but it doesn't go far enough.
It's darn misleading because, unlike the modern manual, it does not provide the power figures (amperages) at idle. Thus after reading that old manual, it sure looks like having having power factor correction capacitors is the way to go... 29% less power used to weld... when in fact your machine may be costing you a fortune because of a major (~400%) increase in idle power consumption. IMO, THAT'S MISLEADING INFORMATION!
There's two sides to every coin; just because it's not stated in the old manual, does not mean it's not happening. Best be aware of it.[snipped]

T

Bluewelders
10-04-2011, 04:43 PM
The power factor capacitors are on the AC side of the transformer.
They charge and discharge each cycle.
By balancing the lead and lag of the inductance and capacitance.they they bring the power factor to a more nearly resistive amount.

snoeproe
10-04-2011, 08:30 PM
Rick
Why are you trying to oooooo and aawwee and baffle me with your ohm's law calculations?
This may work with the newbies on this board but it isn't going to work with me or any of the other guys on this board who are experienced and skilled in this field.
I hold cetification with the CWB in structural plate with stick. I also hold pipe tickets with the TSSA, carbon steel with stick and stainless steel with tig.
I am also a certified operating engineer, also with the TSSA.
What qualifications do you have Rick.?

BCTimberwolf
10-04-2011, 09:59 PM
aww come on now...keep it on topic. Go play who's dick is bigger somewhere else

Rick V
10-05-2011, 08:17 AM
What you indicated to us all in your above post is that you dont understand the concept of duty cycle with a welding powersource.. Thats a lot of posts for a fellow who appears to not understand the duty cycle concept...


Rick
Why are you trying to oooooo and aawwee and baffle me with your ohm's law calculations? This may work with the newbies on this board but it isn't going to work with me or any of the other guys on this board who are experienced and skilled in this field.

What's with you snoeproe? First you attack me with, "you dont understand the concept of duty cycle". When I show you that I do, you attack me again with "Why are you trying to oooooo and aawwee and baffle me with your ohm's law calculations?"
You are provoking me, for no apparent reason other than to put me down so you can look the expert.
I agree with BCTimberwolf, "Go play who's dick is bigger somewhere else." :laugh:

farmall
10-05-2011, 12:54 PM
Just tun the welder on, weld up your project and turn it off. Don't let set there with just the fan running.

Yup. It really is that simple. Works even with my beastly Miller 340. If you use a lot of juice you are welding enough for that not to matter much in comparison to amount of weld produced.

Of course the ideal solution is for everyone to give me their archaic transformer machines and buy inverters.