Re: Oscilloscope to view mains power

>
> Make sure that the front end of your scope can handle the peak voltage of
any AC
> voltage you will be measuring, divided by the probe factor if appropriate.
For
> example a 120 VAC RMS line will have a peak voltage of 170 V to
neutral/ground
> (1.414 * RMS Voltage). AC voltmeters read RMS voltage. In this case,
your
> scope would need to have a peak rating greater than 170 VDC if you use 1X
probes
> and greater than 17 VDC if you use 10X probes.

Thanks for that.

>
> Also, remember that the shield on your scope is connected to ground so be
> careful not to connect the ground lead of your probe to the line side
instead of
> the neutral. If you do, you will likely ruin your scope probe. Using a
> step-down transformer will provide isolation and eliminate this problem.

I read elsewhere that if I don't care too much about accurate voltage
measurements, I can just connect the probe tip to neutral or active and not
bother about connecting the probe shield.

The scope will then show the PD between the probe tip and the internal scope
ground (which should be the same as the power points ground since they'll be
on the same house power circuit - except when I'm measuring the inverter).

No circuit between the probe tip and its shield would seem to be safer, on
the face of it.

Does that make sense?

tia,
RR


.

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