Plasma Cutter Repair

[DonW]

I am a noob to this forum, and to be honest don't know a whole lot about electronics. I recently acquired a non-working L-Tec Plasma cutter. Upon opening the case I found a capaitor and a varistor laying in the bottom of the unit. Upon inspection, I found that they had been attached to the main power switch as the leads from the components are still attached. It appears they were bridged across the poles of the switch. I am assuming that perhaps someone had attached it to a power source above its 240V rating and that is why they failed (or maybe I should say "worked" if they kept from frying the rest of the machine). The problem is I cannot find a source for the capacitor. It is a RIFA PME 271E Class X1 350VAC EMI suppression capacitor. It has markings of 47n which I'm assuming is the cap value which if so would be the mfg part number PME271E547MR30. I can find data etc. on it but cannot find a source to buy one (without a huge min. qty buy). Can anyone tell me if I can substitute another brand size/ etc. and where to buy? Any help would be greatly appreciated.

 

[Resqueline]

Are they blown off or did their legs just break off from vibration? They're there only for noise & spike protection anyway.
Their absense would not make the machine non-working, but if they're blown off it could indicate a mains spike has taken something else out too.

 

[DonW]

Thanks for the fast reply Resquelene! It's hard to tell if they broke off or melted off. They aren't really "balled" or anything like they melted, but they do exhibit darkness on one side like it may have been from smoke. As I mentioned, I know very little about electronics so I didn't realize that the machine would still function without these components, so I guess I'm not going to get lucky that it is something as simple as this. I did notice that the main power switch doesn't feel "right" in that it doesn't seem to have a solid detent feel in the "on" position and trips to off with just a little pressure. I guess I could test the switch by checking continuity with the switch in the off and on position. Correct? I cannot find any information on this unit. No owners manual, schematics, nothing available that I have found so far. If it is the switch, could the switch just be jumped out and the unit turned on and off via a breaker box.

 

[Resqueline]

If they blew off they would hardly be intact at all and there would be soot all over the place from the blast.
If they broke off - the pins would still be there (and be looking nice) even if broken flush with the body.
The darkness on one side may just be from workshop dust gathering on their upper side.
Check out the switch, either by ohming it as you suggest - or checking for mains voltage present after the switch.
I guess using the breaker as a switch could be done as a test, but I don't think they're made for that kind of duty. Idk.