solenoid tester current

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don_resqcapt19

don_resqcapt19

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In a previous thread there was a discussion of the current load on the circuit when you use a solenoid type tester. The following information is based on using an Ideal Vol-Con #61-076, a Fluke 189 DMM and an Amprobe AMB-6D insulation resistance tester.

First I tried to get the DC resistance using the Fluke and read a value of 23 meg. I then tried the low resistance function of the Amprobe an got a reading of greater than 99.9 ohms with a current of 220 mA. I also tried the Amprobe at 500 volts and got a reading of less than 0.01 meg. I am not sure what else is in the Vol-Con, but it does not appear that I am reading directly across the solenoid coil itself.

I then measured the acutal current draw at 122 volts and at 244 volts. I measured both steady state current and peak current (the resolution of the Fluke for peak current is 2.5?s). At 122 volts the peak was 40.5mA and steady state was 25.8mA. At 244 the peak was 87.8mA and steady state was 55.8mA.
 
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gar

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100215-1032 EST

Thanks for the tests Don.

Your 122 V impedance was about 4730 ohms and the 244 about 4370 ohms.

Your peak current measurements predict a somewhat higher RMS than what you read, but in the ball park. There may be current waveform distortion from saturation in the magnetic circuit.

Possibly has a capacitor in series with the solenoid.

.
 
don_resqcapt19

don_resqcapt19

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gar said:
100215-1032 EST

Thanks for the tests Don.

Your 122 V impedance was about 4730 ohms and the 244 about 4370 ohms.

Your peak current measurements predict a somewhat higher RMS than what you read, but in the ball park. There may be current waveform distortion from saturation in the magnetic circuit.

Possibly has a capacitor in series with the solenoid.

.
Click to expand...
Given that the tester is rated to 500 volts should we expect magnetic saturation at 244? This tester also has a continuity test so there must be something in the circuit that disconnects the battery when testing voltage. I was surprised to see that the continuity indicator comes on at 500k ohms.
 
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gar

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100216-2253 EST

Don:

I did a Google search to see if I could find out what is inside a Wiggy.

A search string to Google:
what is the internal construction of a wiggy meter

The first Google result is this:
http://wiggys.com/legacy/spring-05.cfm
Interesting but not on the subject.

The others are about as funny in relation to my goal.

.
 
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wptski

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Warren, MI
ATSman

ATSman

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Caution! High Energy Circuits!

Caution! High Energy Circuits!

wptski said:
gar:

This might help just a little bit if any: http://us.fluke.com/usen/Products/solenoid
Click to expand...

Interesting article but I think it did not focus enough on the safety aspect
of using a Wiggy on High Energy circuits. I have watched in sheer horror at an electrician using a solenoid tester to measure V on a 4000A, 480V bus without any PPE.
Fortunately nothing happened but the potential of the coil shorting
out, ionizing the air between phases (on 480V) and causing an arc flash and instant death was there. These testers are not fused with CLF's and should never be used around bus bars with high available fault currents. Don't forget, very high currents can flow (10-40KA) before a switchboard main breaker will trip on an instantaneous fault. I learned the hard way about 30yrs ago when I was using one of the first DVM's on the market (Data Precision) I was measuring voltage at the secondary of a 20KVA xfmr when the meter internally faulted, caused a phase to phase fault and blew me across the room. The meter was fused with a non CLF fuse which was part of the problem.
Arc flash labels tell you what PPE to wear but not what type of meter to use !.....a word to the wise :)
 
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