Xylem SSW-07 Soft-Starter - Manual (Page 47)

CHAPTER 5 - PROGRAMMING INFORMATION AND SUGGESTIONS
46
English
Example of readjustment of the nominal current:
I
SSW-07
= 30 A
I
MOTOR
= 25 A
S. F. = 1.15
Setting of the Motor Current = I
MOTOR
x S.F. / I
SSW-07
= 25 A x 1.15 /
30 A = 96 %
ATTENTION!
The increased motor current has direct impact on the maximum
thermal class, that protects the motor, even if the S.F. parameter is
set.
Determine the maximum thermal class, considering the service
factor:
Stall Current = 6.6 x ln
Hot Stall Time = 6 s
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.