ABB 615 series Technical Manual page 457

1MAC059074-MB A
615 series ANSI
Technical Manual
VG
IG
GFC release
Trip timer
Reset timer
PICKUP
TRIP
Reset delay time
Pickup delay time
GUID-D2629C82-34BA-4E64-99E8-B3541D5016B4 V1 EN
Figure 216: Operation in "General EF" mode
Operation mode "Alarming EF" is applicable in all kinds of ground faults in ungrounded
and compensated networks, where fault detection is only alarming. It is intended to detect
ground faults regardless of their type (transient, intermittent or restriking, permanent, high
or low ohmic). The setting Voltage pickup value defines the basic sensitivity of the 67YN
function. In "Alarming EF" mode, the operate timer is started during the following
conditions.
• Ground fault is detected by the GFC
• Fault direction equals Directional mode setting
• Estimated stabilized fundamental frequency residual current exceeds the set Min trip
current level
Trip delay time
Pickup delay time
Section 4
Protection functions
451