The functions (except earth fault protection) are based on full load current, which is the maximum allowed continuous on load current of the motor. The presets, in percent, can be calculated from the following formula:
I q % = full load current preset in percentage
I q = maximum allowed continous on load current = full load current
I CT = rated primary current of current transformer
Example:
ABB motor M2BA 315 SMC 4B3
Pn = 160 kW, ln = 282 A, 400 V used with 5 % overload allowed by the manufacturer
Full load current: l q = 282 A x 1.05 = 296 A
SPEM type selected from the table on page 9, SPEM40 B310 (with earth fault protection) setting value:
Select switches S8 and S4. Fixed 60% no need to select.
(60 + 32 +2) % = 94 % < 95 %
The t6 time for the motor: M2BA 315 SMC 4B3 is 15 s (information from motor manufacturer).