Current measure with multimeter (help)

[Marvo]

I will remove the L1 phase from the motor and connect it to the Black probe, then I will hold the red probe to the U1 input on the motor. Do I understand correctly?

I wouldn't do this test by just holding the probes onto the terminal and wire, you need to figure out a way to make the probe connections more permanent and less prone to moving around or slipping.
I'd advise against doing the test this way although it's not inherently a 'bad' test there's several ways it could go pear shaped for someone that's not experienced.

 

[brianmoooore]

Although @brianmoooore 's advice is very good and useful, I have to side with @Avo Mk8 & @James that as soon as you have to do anything fancy to safely use a multimeter, you are better to simply use a clamp ammeter.

Of course a clamp meter is far preferable, but my post was to illustrate that there's more than one way of killing a cat, so to speak.
Both my methods avoid the problem of switching heavy currents with meter probes.

 

[MJPD29]

I will remove the L1 phase from the motor and connect it to the Black probe, then I will hold the red probe to the U1 input on the motor. Do I understand correctly?

Don’t hold it on with your fingers or you will be the latest dodo to become extinct