Siemens 3RK1308‑0 00‑0CP0 Series Equipment Manual page 79

Trip class
The trip class (CLASS) specifies the maximum time within which a protective device must
trip from a cold state at 7.2 x the setting current (motor protection to IEC 60947-2). The
tripping characteristics represent the time to trip as a function of the current multiple. The
continuous black line in the following diagrams illustrates the tripping characteristic curve for
three-pole symmetrical loads and for single-phase loads. The continuous red line illustrates
the tripping characteristic curve for three-pole loads when one phase fails.
The following diagram shows the overload protection for CLASS OFF:
Figure 6-6 CLASS OFF overload protection
Motor starter (3RK1308‑0**00‑0CP0)
Equipment Manual, 11/2019, A5E34821005002A/RS-AC/003
Functions
6.5 Overload protection
79