On Friday 05 February 2016 23:22:35 Dave Cole wrote: > I'm familiar with Hill Billy engineering.. > > Be careful when taking single phase off 3 phase. Phase to neutral is > what you want of course, but if you somehow make a wiring mistake (or > they did in the past), you can easily get line to line voltage in a > place you don't want it to be. The result can be large amounts of > smoke and some fire! Don't ask how I know this... :-/ > > Dave
In my old home stomping grounds of central Iowa, we called that Shade Tree Mechanicing. 6 of one, half a dozen of the other. :) But in splitting off a 3 phase circuit, I'd sure want to be assured it wasn't setup by the power folks as a "wild leg" circuit that was popular 65 years ago. The only fix for that, that is IMO correct, is a delta primary, 1/1 ratio but wye secondary isolation transformer of suitable kilowatt rating. And just to be a jerk about it, I'd sue to put it in front of the electrical metering, making the power company absorb the 3 to 5% loses in such a setup. > On 2/5/2016 11:09 PM, Todd Zuercher wrote: > > This is the last of our old grandfathered in hill billy engineer > > machines that I have to bring into the modern era. Adding an e-stop > > system is in the plan as well. I am still amazed that the > > electrical contractor who installed the machine when we moved to the > > new shop in 2008 agreed to put it in this way. > > > > My plan was to put in a new panel with a disconnect and feed it with > > a 40amp 3-phase breaker from the main panel. Then from the > > disconnect split it off into 9 single phase breakers. There already > > are contactors and such in the control system, adding the e-stop > > loop will be very easy. Sounds like an interesting machine. I know where there is an 8 spindle machine, at a split rail fenceing maker, but I believe that one has just 2 motors, one for each 4 spindles. It does the rail holes in the fenceposts, doing the 3 holes each in a 3 rail fencepost, in 8 posts at once in about 2 minutes, not counting the load/unload time. By brute force, I don't think the tooling has been sharpened in a decade. So the holes are ragged & splintery, but its still (shrug) a usable hole. Probably have 20 such posts wrapped around my place. But the original installer spaced them about 2 feet closer together than std, so when I have to replace a rotted rail, I have to saw off a couple feet of one of those rails, and get out my electric hand plane to put a new taper on the end of the rail. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
