"Bob La Londe" wrote in message news:u757su$3rfhe$
[email protected]...
The little Ideal meter was a gift from my dad when I started messing
with 3 phase CNC stuff. He thought I might need to be able to read
phase rotation. I have never used it for that. I am aware that running
some types of pumps backwards could destroy them, but a spindle is
faster and easier to check with the poor boy "run it and see" method.
This meter has a CAP test function and it seems to read okay.
Bob La Londe
---------------------
I looked up this Ideal meter to see how much voltage it applies to the cap,
but it doesn't say.
https://www.elliottelectric.com/Media/61361-IDE-4-0-InstallationSheet.pdf
Hand-held, battery powered meters generally don't apply a high voltage to
the Device Under Test, as it would be dangerous to the user. My high voltage leakage tester produces the voltage with a hand-cranked generator, which
keeps both your hands occupied and off the test leads. Measuring the capacitance at low voltage won't detect faults like leakage at a higher voltage.
An expensive professional high voltage insulation tester:
https://www.zoro.com/aemc-instruments-hand-cranked-megohmmeter-1000vdc-6503/i/G3546541/?utm_source=google&utm_medium=surfaces&utm_campaign=shopping%20feed&utm_content=free%20google%20shopping%20clicks
My cheaper one:
https://www.cncest.com/products/metal-shell-1000v-resistanc-meter-insulation-tester-insulation-resistance-tester-with-handle-shaking-test-of-various-motors?gad=1
By paralleling a DVM it will find capacitor (and motor) insulation breakdown voltage, though its low output current charges electrolytics very slowly.
The built-in meter measures and displays the ratio of voltage to current
which equals resistance, but not the voltage itself. That's regulated by a centrifugal slip clutch on the generator.
I was lucky to be out sick the day some recently graduated electrical
engineers tested the phase rotation on a large power supply next to where I
was working. I came back to a black stain on the floor and up the side of
the machine I was building, and never saw them again. It seems they had been squatting beside the supply, touching the 480V cables to the input
terminals, and one slipped and touched a large DC electrolytic.
--- SoupGate-Win32 v1.05
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