Hello every one.
We have a 360kw/690Vac motor feed by a Sinamics S120/560Kw inverter. We think there are transient voltages more than 2Kv on the windings because of reflection. so we decide to buy a Fluke Motor Drive Analyzer MDA-550 for this measurement. But manuals said this equipment can measure max voltage of 1000v. Even 100:1 probes have max voltage 1000 V CAT III, 600 V CAT IV .
What Should we do? Is there anyway to measure 4Kv with MDA-550? If not which product can do it?

 

Welcome to AAC.

Since the specifications of the scope say it has a maximum readout of 3000V, it is probably best to contact a Fluke sales engineer with your question.

 

The measurement category (CAT) is the electrical safety rating of the instrument.

A CAT III rating for 1,000V (and a CAT IV rating for 600V) have an impulse/transient rating of 8,000V – therefore there should be no issue using the instrument as planned (unless the circuit impulse/transient voltage exceeds 8kV).

For more info on CAT ratings see this link:-

https://www.digikey.co.uk/en/blog/what-are-multimeter-cat-safety-ratings

 

The measurement category (CAT) is the electrical safety rating of the instrument.

A CAT III rating for 1,000V (and a CAT IV rating for 600V) have an impulse/transient rating of 8,000V – therefore there should be no issue using the instrument as planned (unless the circuit impulse/transient voltage exceeds 8kV).

For more info on CAT ratings see this link:-

https://www.digikey.co.uk/en/blog/what-are-multimeter-cat-safety-ratings

Thank you Hymie
It seems 10:1 and 100:1 probes have the same voltage range and CAT, so what is the difference between them.
another question: It's transient voltage if there is 2Kv on the probe tip for 500ms?

 

With both the 10:1 and 100:1 probes being the same CAT rating, their insulation systems are rated for the same continuous/transient voltage.

I’d recommend you start by using the x100 probe and if the instrument can handle 10x the input voltage, then the instrument resolution/accuracy may be improved using the x10 probe. But whichever probe you are using, check with whatever scale you have set on the instrument that the waveform is not clipping.

Normally the instrument has to be set manually to the x1, x10, x100 probe in use.

The test transient voltage applied to qualify the insulation system is a 1.2/50 µs waveform – in other words the waveform rises in 1.2 µs and falls to 50% of the peak voltage in 50 µs. So an input transient voltage lasting 500 ms would significantly exceed this time period, but with the capability to withstand an 8kV 1.2/50 µs waveform, an input of 2kV (for 500 ms) should not cause an issue given the required creepage/clearance distances within the insulation for a 1,000V CAT III probe.

 

With both the 10:1 and 100:1 probes being the same CAT rating, their insulation systems are rated for the same continuous/transient voltage.

I’d recommend you start by using the x100 probe and if the instrument can handle 10x the input voltage, then the instrument resolution/accuracy may be improved using the x10 probe. But whichever probe you are using, check with whatever scale you have set on the instrument that the waveform is not clipping.

Normally the instrument has to be set manually to the x1, x10, x100 probe in use.

The test transient voltage applied to qualify the insulation system is a 1.2/50 µs waveform – in other words the waveform rises in 1.2 µs and falls to 50% of the peak voltage in 50 µs. So an input transient voltage lasting 500 ms would significantly exceed this time period, but with the capability to withstand an 8kV 1.2/50 µs waveform, an input of 2kV (for 500 ms) should not cause an issue given the required creepage/clearance distances within the insulation for a 1,000V CAT III probe.

Thank you so much Hymie. that was so useful.

 

Glad to be of service – these Fluke instruments have many functions/settings; to get the most out of it you should have a good play to see what it can do. And if all else fails – read the operating manual.