Ground Fault Alarm (Drive Trip)
ABB · ACS880-07 Hardware
What does ALARM 1 mean?
This alarm signal from the ground fault monitor (option +Q954) is explicitly recommended to be connected for immediate drive tripping upon detection of a ground fault in IT (ungrounded) systems. The contact is normally closed when no ground fault is present and has a load capacity of 250 V AC, 2 A. Be aware that the ground fault monitor performs self-testing, which might momentarily activate this signal, necessitating careful distinction between actual faults and test sequences.
Additional Steps
Steps 1–2 are listed in Priority Fix.
- 3
Inspect the wiring integrity of the 'Alarm 1' connection at terminal X954 (pin 1) to ensure secure connections to the drive's trip input and rule out loose contacts.
- 4
Verify that the ground fault monitor itself is functioning correctly and is properly calibrated according to the IT (ungrounded) system requirements.