WEG CFW-11 Programming Manual page 205

Example: For a motor with the following characteristics,
I = 10.8 A
n
T = 4 s (hot motor blocked rotor time)
BR
= 7.8 ⇒ I
I / I = 7.8 x 10.8 A= 84.2 A
p n p
SF = 1.15
one gets,
Overload Current =
After this, it is only necessary to plot the calculated values on the motor overload graph (figures 15.3 (a) or 15.3 (b),
and to select the thermal class curve immediately below the calculated point.
Figure 15.3 (a) - Cold motor overload curves for loads of the HD and ND types
I 84.2
p
=
I x SF 10.8 x 1.15
n
Overload Time = T = 4 s
BR
Faults and Alarms
x 100 = 678 %
15
15-7