Troubleshooting Altistart 46

[Abanoub Magdy]

I have a little issue

I have Soft Starter Altistart 46 Runs 110 KW motor

The motor current ( on Clamp meter ) is 181 A, 180 A, 184 A but on the display of the soft starter is 188 A or 191 A

why this difference ? Or what causes this difference ?

Thanks in advance

 

[petersonra]

Calibration maybe.

I have seen this kind of thing pretty regularly.

5 amps out of 180 is less than 3%. How accurate does your meter claim to be? When was the last time you had your meter calibrated?

The accuracy of many such meters is stated as a percent of full scale. You might be within the promised accuracy range.

 

[jim dungar]

Is the starter running in bypass mode when you are making your measurements, or are the SCRs still in the circuit?

Clamp-on meters might not have the same accuracy, for harmonic laden currents, as the toroidal CTs used internally in the starter.