- Occupation
- Licensed Electrician
Knopp K60 comes new in the box with a Cat III rating.
Wiggies...solenoid testers...where did they go?
- Thread starter jaylectricity
- Start date
- Status
- Location
- Illinois
- Occupation
- retired electrician
My Ideal Vol-Con also has a CAT III rating.
StarCat
Industrial Engineering Tech
- Location
- Moab, UT USA
- Occupation
- Imdustrial Engineering Technician - HVACR Electrical and Mechanical Systems
The other thing is those " Kids " cannot function at all without an instant internet connection and do not seem to be inclined to learn and memorize things.
K8MHZ
Senior Member
- Occupation
- Electrician
I like my Ideal Vol-Con XL's
That’s.not a solenoid tester. It is made to look like one.
How do you even know? You can’t see it. When we stopped using them the PLC inputs stopped failing almost completely. Before then we replaced cards regularly.
You can’t see the damage without cutting the input transistors apart.
This is what you are looking for but a little hard to see without an electron microscope handy.
- Occupation
- Licensed Electrician
I''m afraid you a quite wrong about that.
https://www.tescometering.com/wp-content/uploads/2019/01/Knopp-K-60-Voltage-Tester-PDF.pdf
.... the key criteria! Dual voltage indication is provided by solenoid and neon
lamp, operating independently.
A solenoid tester is a coil and a spring loaded indicator. Think of an old Simpson analog meter but more primitive. The big difference is the analog meters are meant to unobtrusively read voltage. Input resistance is 40-100k. Electronic meters are megaohms. Solenoids by nature are 10-30k. These days the multimeters come with a built in low Z feature and Fluke makes a plug in resistor for the ones without it.
The inherent problem with solenoid testers is it’s just a coil. If you test it at 6-8 kV (CAT III) what do you think is going to happen? It arcs and the coil burns up but more often than not you get a small open air arc flash. The whole point of the CAT rating is to prevent this. The only way to prevent damage is either much higher input impedance (the multimeter trick) or some kind of fuse but fuses are current protection, not voltage. A surge arrester would fail since by nature it shorts a surge. You can’t fix the solenoid tester design.
The Vol Con states that it has some kind of voltage tester electronics that drive an isolated coil as an indicator. That’s your hint right there. The movement is just a simulated solenoid tester. That thing is a low Z multimeter disguised as a solenoid meter. I know the argument is if it quacks like a duck but I don’t think anyone gets confused by the duck boats in some cities that have ducks painted in the sides full of people making quacking sounds.
Prior to around 2000 a lot of meters, analog, solenoid, and digital, had this issue. Once the IEC and UL CAT rating came out NOT having a compliant meter became a huge liability issue. Before then it was like arc flash in the panels...nobody was going to get sued because you did not turn your head and hope the breaker did not blow up. It was just a risky business. The meters that never had an issue got a model number bump and a new CAT label. A lot of Radio Shack $9.95 stuff was just discontinued. Many were redesigned. The prices went up.
The Vol Con has as much to do with an original Wiggy as the Square D tester that replaced it does. Square D kept the name for a while but that’s all they have in common.
As far as CAT ratings it’s not a solved issue either. Eevblog tests meters independently. A lot don’t pass their CAT label including a lot of Flukes.
So if you’ve used a “solenoid tester” and if it’s less than 15-20 years old especially if it has a CAT rating it’s not a solenoid tester at all. It’s just made to look like one. Open it up and see if you find a coil, a DC motor (buzzer/indicator) and a battery and a light. That’s a solenoid tester with continuity and DC/direction. No circuit boards, diodes, transistors, or chips of any kind. Back in the day mist guys bought either the Simpsons or the solenoid testers (or both). My dads hand me down was a Simpson (after the Radio Shack meter failed) and I bought a solenoid tester back in the 1980s. I went digital in the 1990s but does tests still needed the Simpson until electronics got fast enough to catch up 20 years later. Switching is an easy decision when a contractor hooks up a 2300:480 transformer backwards (step up instead of step down) and a buddy tries to test the output with a non-CAT rated Fluke. It turned into a “fuse” for an arc flash and sent the guy to the hospital.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
You'd have to prove that to me.
synchro
Senior Member
- Location
- Chicago, IL
- Occupation
- EE
As the coil is removed, the current continues to flow in the same direction through an arc as the ½ L I² energy stored in the coil is discharged. The voltage at the coil (and therefore on its side of the arc) may fall and then possibly reverse in polarity and rise in magnitude, but the voltage at the equipment side of the arc can maintain substantially the same value as the current drawn from it decays.
A problem can arise if the inductor maintains its contact to the equipment, but the equipment is shut off or otherwise stops being able to supply current in an abrupt manner. Then the voltage across the coil will reverse in polarity and the voltage will rise as necessary to discharge the stored energy. If the equipment does not have suitable diodes or other means to safely clamp this voltage it's possible that damage could occur on sensitive semiconductor devices.
A problem can arise if the inductor maintains its contact to the equipment, but the equipment is shut off or otherwise stops being able to supply current in an abrupt manner. Then the voltage across the coil will reverse in polarity and the voltage will rise as necessary to discharge the stored energy. If the equipment does not have suitable diodes or other means to safely clamp this voltage it's possible that damage could occur on sensitive semiconductor devices.
jaylectricity
Senior Member
- Location
- Massachusetts
- Occupation
- licensed journeyman electrician
Sorry...I haven't been back in awhile. That is indeed what I bought. It took a little getting used to putting the leads into the rubber holders as opposed to just sticking them into the body. But it's fine. Progress. Life.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Jay, may I presume you also know either probe can be slid into the top center of the back?
MTW
Senior Member
- Location
- SE Michigan
For those of you that need an instruction sheet for your old wiggy. Came across this from an old timers collection.
- Location
- Illinois
- Occupation
- retired electrician
We rarely saw card failures. We certainly were not replacing cards on a regular basis. I am working on a project now were some I/O racks and cards that have been obsolete for over 20 years will be replaced next year.
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