Difference in pedals...

admin

What is the difference between a RFC-14 and RFCS-14 tig pedals? They seem to have the same connectors.
Reply:I"m going to take a stab at this since no-one who actually knows the answer has responded.As always, the first place to check this kind of question is Miller's web site.See   http://www.millerwelds.com/om/o826n_mil.pdf    for the RFC-14.See   http://www.millerwelds.com/om/o844g_mil.pdf    for the RFCS-14.I don't have an RFC(S)-14 or a Synchrowave and the manuals for the two pedals are only marginally helpful.  The RFC-14 manual only shows details on the RFC-23 series pedals, but one can infer that the RFC-14 is similar except for the connectors and the resistance (but that's a guess).Superficially, it looks like the RFC-14 has a large, power variable resistor and has no noise filtering capacitors, whereas the RFCS-14 has a smaller, and therefore lower power, rotary potentiometer with two filter capacitors from the pot wiper to each end of the pot.  The RFCS-14 has a 1000 Ohm, gear-driven rotary pot.  The manual for the RFC-14 AND RFC-23 series shows in the parts list three resistor options without telling us which goes to which pedal.  The three are 15 or 1000 Ohm @ 130 Watts or 25 Ohms @ 300 watts (a bundle of four resistors).   My GUESS is that the 1000 Ohm resistor is used in the RFC-14 (just by comparison with the RFCS-14).The question is, why would Miller use a 130 Watt, 1000 Ohm variable resistor in a foot pedal.  A 130 watt 1000 Ohm resistor implies a maximum of 360 volts to the pot, which is ridiculous.My next GUESS is that Miller may have just taken an existing product that used a low-value resistor for direct control current modulation and substituted a high resistance, unnecessarily high power variable resistor to create a foot pedal with the same form factor so they could use all the same parts for low cost production of the RFC-14.  They had to provide a 130 Watt resistor to make it work with the existing hardware.  Then they developed the RFCS-14 to take advantage of the lower power, cheaper(?) rotary pot, which was all they really needed for that pedal, anyway.  Just a guess.The -14 apparently refers to the 14-pin external control connector on many welders.  The pinouts of the two pedals appear to be identical, I think the two would be interchangeable because it is clear that the 130 Watt 1000 Ohm pot in the RFC-14 is way overrated for the task.I think the only risk in just trying it out would be if the RFC-14 actually had a low (15 Ohm) resistance.  In that case, you could overload the control circuitry in the machine and cause damage.  You can avoid that by simply making sure the RFC-14 has a pot resistance of 1000 Ohms, not 15 Ohms.That's my guess.  Any RFC(S)-14 owners out there willing to measure resistance of their pedals?Hope this helps.awright
Reply:are you looking for one for your welder, if so i would get the one the manual calls for with the wrong resistance you could have problems.SCS makes realy nice controles at a realy good $$. summer is here, plant a tree for mother earth. if you dont have time or space, sponcer some one else to plant one for you.feel free to shoot me a PM or e-mail me at [email][email protected] i got lots of time.
Reply:Just measured my rfcs-14(hd)... 1k ohm.I wonder if the 15 ohm model isn't for the older machines ( like my hobart ) where the pot controls saturation in the reactor core?  It's a heavy ceramic wire wound unit.  been a while since I measured it, but just a guess.
Reply:I just realized I have one of each of these. The RFC-14 that came with my synchrowave 250 is quite a bit beefier loooking and heavier than the RFCS-14 from my econotig. Looks like the same connector, but I have not tried swapping them.
Reply:i dont think i would try a swop without finding out the ohms of them both first. i would hate to toast one just because the plugs match. summer is here, plant a tree for mother earth. if you dont have time or space, sponcer some one else to plant one for you.feel free to shoot me a PM or e-mail me at [email][email protected] i got lots of time.
Reply:alanaker, how about measuring the resistance of your two pedals to resolve the question we had about that?Thanks.awright
Reply:Umm, o.k. Resistance between which pins?
Reply:All the 14 pin devices are 1000 ohm. You are ok with any of them. The 15 ohm are for the old 330ABP or Dialarc series and have two cords and two plugs. The one with the four large resistor assembly are for the old Trailblazer 44 series.
Reply:There you go!  Just had to wait around keeping the discussion alive until someone who knows the answer notices the thread.  Thanks, weldersales.By the way, out of curiosity, is my guess about the evolution of the RFC-14 with the 130 watt, 1000 ohm resistor correct?  Is there any other feasible explanation for using such a variable resistor?awright
Reply:awright, I had wondered that for years and I suspect that you are right - Miller had been building that big RFC23A for years and then when they needed a 1000 ohm unit for their new machines in about late 70's all they had to do was to get a 1000 ohm fixed resistor and plug it into that old dog and shove it out the door. I can remember people saying they liked the 'sturdy' or 'tough' style of the old control. When Miller first tried to use the smaller units, they called them 'E' for economy units. Then, all of a sudden, customers began to say they liked the new 'compact' design, allowing the discriminating operator to get his control in tighter places. Kind of went the way of the standard 'desktop' computer, huh?