From: John De Armond Newsgroups: alt.home.repair,misc.rural Subject: Re: unstable, fluctuating house current? Date: Mon, 02 Jan 2006 01:32:57 -0500 Message-ID: <l2ihr15tc0d3dojbltfjn5t6suh1jrees0@4ax.com> On Mon, 02 Jan 2006 02:08:52 GMT, CJT <abujlehc@prodigy.net> wrote: >Neon John wrote: > >> On Sun, 01 Jan 2006 08:50:51 -0500, mm <NOPSAMmm2005@bigfoot.com> >> wrote: >> >> >> >>>I'm pretty sure most people have never heard them called solenoid >>>operated voltmeters. .If you want people to understand, I'd either >>>explain what I meant, or call them mechanical voltmeters, (or >>>electromechanical, or wire coil, or moving needle VOMs) >>> >>>What is Wiggy? >> >> >> "Solenoid meter" is the only thing I've ever heard it called besides a >> Wiggy. Wiggy is (I think) Square D's brand name for a solenoid meter. >> >> A solenoid meter does not have a needle. It has a plunger that gets >> sucked into a solenoid, the depth of which depends on the voltage. A >> real Wiggy also has a polarity indicating magnet on top. Some other >> brands have neon bulbs mounted on the plunger to aid in seeing it. It >> is a low impedance device that does not respond to leakage current. >> >> Instead of sowing confusion, why not google it? >Then you ought to be able to use a digital voltmeter with an appropriate >(high resistance -- not like one for a current meter) shunt to achieve >the same result. If you insist. Of course, you still have to keep the meter in view and have enough light to read it. The Wiggy buzzes and vibrates when energized. After a little experience, one doesn't need to look at the thing to see what it's reading. Right tool for the job and all that. I can cut down a tree with a coping saw but with a chainsaw close at hand, why? Wiggys are cheap and really are the right tool for the job of troubleshooting power electrics. John From: John De Armond Newsgroups: alt.home.repair,misc.rural Subject: Re: unstable, fluctuating house current? Date: Mon, 02 Jan 2006 04:18:26 -0500 Message-ID: <mnqhr1pgu8cqpprmhlir5ik7l4mh5696ea@4ax.com> On Mon, 02 Jan 2006 01:18:19 -0500, mm <NOPSAMmm2005@bigfoot.com> wrote: >>Instead of sowing confusion, why not google it? > >I did. I googled solenoid meter and solenoid meter wiggy. I forget >the details but didn't find anything relevant, except when I looked up >solenoid in the dictionary, apparently it means any coil, not just one >with a moving metal plunger. No one I know uses the word that way, >but I figured the OP might. The first hit on "wiggy voltage tester" was to Home Depot ($19.95) The second was to Square D's site: http://www.squared.com/us/products/machine_safety.nsf/unid/58870E11543C976885256D5 >Also, why would you need a solenoid meter such as you describe, when >it seems to me any low impedance meter would work? Several reasons, in no particular order. It's cheap enough to have one everywhere, even leaving them inside machine cabinets. It indicates if the voltage is AC or DC - quite important when a cabinet has mixed voltages. It's a real pisser to tie into a 250VDC bus because your meter set to AC reads zero. It draws enough current to burn through corroded and otherwise bad connections while not being affected by coupled potentials, ground loops and so on. It covers the full range from about 50 volts to 600 without range switching. No digital nor analog instrument does that, at least without range switching which takes time. There is at least a little response on 24vdc. I can walk down a terminal strip in a cabinet looking for the line voltage without worrying about high voltage DC or even higher voltage AC affecting my meter. I don't have to look at the thing. I can feel and hear its operation. I can even slip it in my shirt pocket and still feel it operate. The Wiggy is totally unaffected by RF. Try using a DVM (except maybe a high end Fluke) inside a large transmitter or around an induction furnace. Even the venerable old Simpson sometimes acts up when the meter protection diodes pick up enough RF. I could probably think of a few more benefits but that's enough for now. > >Are you saying it has to have lower impedance than a classic simpson >VOM for example, or any meter made in the 60's and earlier? IIRC >they are 30,000 or 50,000 ohms per volt. Yep. I can't seem to find a spec on the thing but I'd guess that it draws at least a half amp on 120vac. Almost all reactive power, of course, so no significant wattage involved. I know that the prods draw a pretty significant spark on 480vac. > >That would be surprising to me, and the lower the imdedance the more >the circuit is affected by the meter. When diagnosing power circuits, that's exactly what you want. I don't want a DVM or even a Simpson 260 sitting there reading leakage current through the blown fuse. And I don't want to be chasing my *ss trying to find out why the circuit is still "hot" despite having opened the breaker because my meter is reading stray current coupled into the conductor from others in the conduit. This is a special problem when there are lots of variable speed drives about with their high harmonics. Of course, the opposite holds too. A Wiggy is like a bull in the china shop inside an instrument cabinet. I can think of more than one nuclear plant trip caused by a spark-trician poking his Wiggy where it didn't belong. We actually banned Wiggys from the instrument rooms at the Sequoyah NP. Like I said, the right tool for the right job. BTW, something I'd forgotten until Google reminded me of it. "Wiggy" is the abbreviated name for the inventor of the thing. "Wiggingham Voltage Tester" is the formal name. John |