ABB 615 series Technical Manual page 458

Section 4
Protection functions
452
The PICKUP output is activated once Pickup delay time has elapsed. TRIP output is not
valid in the "Alarming EF" mode. Reset timer is started if any of the above three
conditions are not valid. In case the fault is transient and self-extinguishes, PICKUP
output stays activated until the elapse of reset timer (setting Reset delay time).
In case detection of temporary ground faults is not desired, the activation
of PICKUP output can be delayed with setting Pickup delay time.
To keep the operate timer activated between current spikes during
intermittent or restriking ground fault, the Reset delay time should be set
to a value exceeding the maximum expected time interval between fault
spikes (obtained at full resonance condition). The recommended value is
at least 300 ms.
1MAC059074-MB A
615 series ANSI
Technical Manual