EM-10. Thermal capacity & insulation class

Design drive trains for the two identical conveyors with parameters:

• Speed 200...230 rpm
• Rated torque - 9 kNm

One conveyor has duty of 100%, another one - 80%. Grid is 690 V.

Explain the difference in chosen electric machines for the two cases.

Question-1

Could we have used even smaller machine on the second conveyor? If yes, what insulation class should it have had (assume all motors in DriveConstructor have insulstion class "B")? If we use smaller machine with the same class "B" as before then what would be insulation lifetime (assume in normal load lifetime of 10000 hours)?

Question-2

Is replacing the motor with insulation class "H" with another motor with insulation class "F" possible? What lifetime should be expected? What if insulation class "H" but temperature rise as for class "F"?