Tork boost

[PierreLeCat]

Today I was commissoning a system where one motor was tripping on startup with an OL fault. The fault (in the incerter's book) was about Staled prevention. This motor was not even geting up to speed, it was in fact at about 2 Hz (almost not even moving at this point) when the fault stopped everything.

I connected it accros the line and I worked with acceptable current.

I finaly discovered that someone had adjusted the tork boost to 14%. When I reduce it to 1% all went well.

Can someone tell me what was wrong?

I hunderstand that the tork boost is a voltage boost. Why was it making this drive/motor setup trip?

I taught it could damage the isolation in the motor since it was not an inverter duty motor but why this overload fault at startup?

Specs are:

Motor 230 / 3 / 60 - 2 HP / 1725 RPM (US Motor)
Drive Mitsubishi FRS520 - 2.2Kw

 

[jOmega]

You overexcited the motor and saturated the iron.
Ergo... lots of current ....

The way that boost should be set is from zero to just enough to get the motor and load moving and accelerating.

 

[jbartos]

Suggestion: Contact the manufacturer tech support for the proper parameters since any experimenting could lead to your wasted time, potentially damaged hardware, and bigger expenses.