SChematic help? plasmarc pcm-100 union carbide

[Dawai]

Schematic: plasmarc pcm-100 union carbide

Anyone know where I can locate one?

there used to be one under the lid, but alas.. old age and mice.

If not, then it will be demo'ed for parts. It was cutting 1" metal in a cnc gantry table. Seems a shame, has coolant and all rigged up on it. Got the lid off, I recognize about 98% of everything.. It is a bank of three phase transformers tied together on one side, Wye?? perhaps it could be rigged 220 on Single phase if I knew what I was really looking at.. the bridgeport common shunt transformer sure aggravated me till I chunked it.

Sure has a bunch of relays.. I got a woodie for the capacitors out of it at the moment, and that belt ran coolant rig and single phase blower (tig torch cooler later) It has a high voltage spark gap, but not seen the hv generator box....

[macona]

Call ESAB tech support. They should have the manuals.

The PCM-50 was configurable three or single phase, so maybe the 100 was as well. There should be a big jumper board on one side. The machines name tag also should say the input.

When you get to the 100 amp range it generally more input than you can get a single phase breaker for.

[Dawai]

Thank you sir.. I'll try esab.. Union carbide=esab??

sure wish I could make it work here. If not, well parts is parts.

[Dawai]

Got the barn doors off the plasma cutter.

The main xfrmers are wired 480 Wye, no taps available on the side board hookup, just three connections. That comes off them to some transformers w/common wound wired exciter (current control)

Does not appear to be any way to seperate the secondary drive xfrmer. Since they are common wound around the back side. Front drive side is separated coils. I was scratching my head there for a bit figuring out how they were driving them with two triacs.

Coolant, pump, coil, motor, and fan would work with a tig cooler.

Hi freq transformer, I have not gotten it out into my hand yet, it'll work, as the diode bridge and heat sinks, as the HV spark gap.

It's parts for the next project, a heavy duty edm for the cnc. I will have to saw the primary xfrmer into sections or ignore the other two coils.

there is a ecu, or cpu, or?? lil black box the 50mv current control goes into that turns the relays on and off.. Is there many of these dinosaurs still in use? if so, someone may need these parts I don't.

TORCH is about fifty feet long w/wrap, if you know anyone that needs it too. A vertical machine mount unit. two wire control. liquid coolant

[macona]

Union Carbide became Linde which became L-Tec which was bought by ESAB. There are couple machines like the Heliarc 250HF which can be found with the Linde, L-Tec, or ESAB labels or colors. The 250HF was a darn good machine for its day and remained mostly unchanged for a long time.

Dosnt surprise me much about he old machine being 480. Tough I am surprised it dosnt have taps.

The HV transformer is probably somewhere about 3kv. The 50mv part is probably a current shunt. A plasma cutter is a constant current machine so it need current feedback to regulate it if the output is adjustable. Nothing close to a processor in there. Mostly comparators or opamps in there.

I think you would have to somehow separate the transformer. I believe they dont work well on single phase.

[Dawai]

Hi.

Sounds like you have seen more of these apart. It has two 50mv drives.. one is a ct the push connector on the front goes through, it feeds up to the 200amp meter, nothing else. then there is a 50mv shunt resistor just like you said there they pick off the output current with. Ain't your first rodeo huh?

More interesting is HOW they do it, I am looking, I have a cpu controlled "tiny tig" project I am wanting to add feedback regulation to. Is there a simple way to have a digital feedback/current relation from a known part out of something else? ALSO on the tiny HSM edm I built here from junk.

I have no desire to become a welder repairman. I am a hobbiest, instrument tech/electrician.

If I quit playing? I may have to grow up?

[CountZero]

How much current do you need to measure and is it AC or DC?

Perhaps one of these can be useful to you:http://www.allegromicro.com/en/Produ...rentsensor.asp

[macona]

For current sensing I like the modules from LEM. They will sense AC and DC with the same module and give a DC signal out,

http://www.lem.com/hq/en/content/view/269/206/

The LA series is used in a lot of hypertherm plasmas. The larger units are used in all sorts of machine including both miller and hypertherm. If you have an older miller synchrowave 250 and the main board goes out the replacement kit includes a LEM module to replace the shunt resistor. They are not cheap but they do eliminate a lot of the work of conditioning the signal, isolation, and other fun stuff like that.

I dont thing I have ever seen the insides of one of the machines you have there, but from the same era machines I kind of know what to expect. This machine was from the era of no microcontrollers so everything is analog. Simple and reliable.

[Dawai]

What is left of Hurricane IDA is washing out the old dinosaur of a plasma cutter..

I sat it up onto the one ton truck with the engine-lift swivel.. drove it out of the cherry tomato patch (didn't need the winch) and there at waist level I removed all the panels.

It, like my miller 35amp was full of fabrication shop grit and dirt.. I really don't see how they work with all the stuff in there.. I have to blow my miller out every six months or so.. I can tell you it must be tough, the drive boards are not encapsulated in anything..

When the brain is working better I will research the current feedback module you two posted.. I looked at the first one there.. I can not do surface mount here.. so.. Never geared up for it, and my eyes are not well enough. I have some old 50mv analog digital opto22 modules.. they convert the signal into a frequency output.. NOW that'd work too.. after I figure out how to apply them..

I've been up all night again.. and this insecure pitt bulldog.. has to push up against me to know I am there for him.. really now.. I can however turn on the electric blanket and he remembers mommy and sleeps all day..

[macona]

Dirt really dosnt effect the output of a welder. There are only a couple times when it does bad things. On a plasma or tig machine the dust can get into the HF contacts and stop that from running. Technically dust could build up to such a degree that it would cause overheating and trip the overheat safeties. I have never seen that happen though. And I have seen machine come in with literally 2" of mill scale in the bottom of the machine (They were out of a steel mill)