WEG SSW-08 User Manual - page 47
Manual is about: Soft-Starter
of
55
5
Programming Information and Suggestions
42 | SSW-08
Determine the maximum thermal class, considering the service factor:
Stall Current = 6.6 x ln
Hot Stall Time = 6s
Service Factor = 1.15
Before the maximum thermal class is verified in figure 4.9, the stall current must be divided by
the service factor.
Stall Current / S.F. = 6.6 / 1.15 = 5.74
5.74 x In of the motor
t(s)
6 s
0
xln
25
Hot
20
15
Figure 5.12: Checking of the maximum thermal class, considering the S.F.
Class 20 is the highest class that protects the motor, if the service factor is used.