2.3.3 Power reduction compared to S1
In duty types S4, S5, S7, S8 and S9 the motor power must be reduced, since in
all these cases starting losses or braking losses play a major part.
The computational method is based on the maximum no-load change-over frequency
z0 as shown in Table 2.19.2. This is the maximum allowable hourly
number of reversals without the motor becoming too hot. The maximum allowable
change-over frequency z for a certain load conditions can then be determined
using reduction factors such as the factor of inertia, counter-torque factor,
and load factor.
The factor of inertia FI takes into account the external moments of inertia such
as the moment of inertia of the motor JMot and load moment of inertia Jzus