On 29/12/2019 16:17:04, The Natural Philosopher wrote:
On 29/12/2019 14:52, John Rumm wrote:

I appreciate that motors have a surge at the start.Â* I believe a 50%
margin should be added generally (more for a motor).

Depends on the motor, inrush on some induction motors can be 9x nominal.

In general the better the motor efficiency the worse is the surge.

10x is easily achievable wioth 'good' motors.

cheap chinese motors used in e.g. car window winders are deliberately
pants to that they can be stalled without burning out wires or fuses.

Car window winders are an especially bad example. They use load sensors
to ensure nothing is trapped, such as a child's arm, in the window.

What we did before regulations! Apart from a few children losing arms
and suffocated children of course.