Topic | Another novice question: current clamp usage

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Anonymous
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What would be the best settings for using a current clamp with the option of using 1mV/A or 10mV/A? Would it be using the ports for “V and A” or “A and C”? And should i use the auxiliary settings on the Mooshimeter?

Anonymous
Inactive

Those clamps you mentioned output voltage, so you should connect those first to C and V inputs, at least for now.

If your max currents would be under 1000 (1 mV/A = 1 volt out) or 100 (10 mV/A = 1 volt out) amps, so outputs would stay at under 1 volt, you might want to try auxiliary inputs, which gives you somewhat better resolution with those millivolts. In that case, you would connect you clamp to C and ohm inputs and select aux voltage from mooshimeter interface.

Sadly, there are no way to set mooshimeter to do your math, so you just need to mentally move your decimal point to right place and remember that those mV:s represent amperes.

A-input has nothing to do with the measurement above, however, you could use it as another common input, as A and C only have big fuse and really small resistance between them. So you might have line voltage between V and A inputs (which feels wrong, but then those common leads would not cross each other) and your millivolt output current clamp between C and ohm. Just be very sure that you know what you are doing, it is very easy to fry your multimeter with that many leads connected to it! It is very easy to even get your current clamp energized to line voltage, if you are not sure which lead is live and which is neutral. Take your time.

Then there are current clamps that output (milli-) amperes, but those are for AC only. Those would go to C and A inputs and you likely get a bit lower resolution out from your multimeter with those. I have one with 1000:1 ratio, so it is easy to read, just skip the milli-part from results. Works great with tens of amperes, under one amp it disappears to noise.

Anonymous
Inactive

@Ville. Thank you for the explanation!

Anonymous
Guest

Does this mean I could have an amp clamp on “Ohm” & “C” (assuming max output from the clamp was < 1000mV and voltage leads from “V” to “A” to display both the voltage reading and the clamp reading at the same time? Would it be safer/better to use a pass through banana plug on “C” and measure voltage from “V” to “C” leaving “A” empty? These measurements would be in DC (voltage <= 50V amperage 20mA – 10A / 10A – 500A (different clamps))

Anonymous
Inactive

Using pass through or Y-adapter/leads would be mentally safer, as everything is connected to right place and there is less change to confuse yourself. Electrically there is no difference.

In both cases, there can’t be any potential difference between those common leads. It might be even safer to use both C and A connectors, as there is fuse in between. Current clamps are potential free by nature, so in this case only concern that pops in to my mind is the possibility to connect higher voltage to that current clamp. –>

I live in Finland and our European plugs and sockets fit both ways, so live and neutral are basically (or at least should considerate to be) randomized every time we plug something to wall. And I am an electrician, so I measure 230/400 VAC stuff all the time. With “normal” multimeter and current clamp measuring currents is quite safe thing to do, but when adding mooshimeters ability to measure voltage at the same time, danger levels rise as now I need to remember that the clamp and leads connecting to it might have 230 volts on them.

I’m not trying to spook anyone not to do it, just saying to remember that normally potential free measuring device will end up to some voltage from your setup and will make sparks touching other parts of the thing, if there is broken insulations or some manufacturer has saved some pennies and not insulated the clamp at all.

Anonymous
Guest

thanks for the quick response