ABB RELION REX640 Technical Manual page 769

1MRS759142 C
REX640
Technical Manual
GUID-14B1A333-2759-4189-B3B2-05E173A84EB7 V1 EN
Figure 420: MNSPTOC Inverse Curve B
If the fault disappears, the negative-sequence current drops below the Start value
setting and the START output is deactivated. The function does not reset
instantaneously. Resetting depends on the equation or the Cooling time setting.
The timer is reset in two ways:
• When the negative sequence current drops below start value the subtraction in the
denominator becomes negative and the cumulative sum starts to decrease. The
decrease in the sum indicates the cooling of the machine and the cooling speed
Section 4
Protection functions
763