Self-Supervision; Internal Faults - ABB Relion SMU615 Technical Manual

1MRS758407 B
3.2
3.2.1
SMU615
Technical Manual

Self-supervision

The merging unit's extensive self-supervision system continuously supervises the
software and the electronics. It handles run-time fault situation and informs the user
about a fault through the communication channels.
There are two types of fault indications.
•

Internal faults

• Warnings
Internal faults
When an internal fault is detected, merging unit operation is disabled, the green Ready
LED begins to flash and the self-supervision output contact is activated.
An event about the fault is stored as a message on the WHMI. The text Internal
Fault with an additional text message, a code, date and time, is stored to indicate the
fault type.
Different actions are taken depending on the severity of the fault. The merging unit
tries to eliminate the fault by restarting. After the fault is found to be permanent, the
merging unit stays in the internal fault mode. All other output contacts are released and
locked for the internal fault. The merging unit continues to perform internal tests
during the fault situation.
If an internal fault disappears, the green Ready LED stops flashing and the merging
unit returns to the normal service state.
The self-supervision signal output operates on the closed-circuit principle. Under
normal conditions, the merging unit is energized and the contact gaps 3-5 in slot X100
is closed. If the auxiliary power supply fails or an internal fault is detected, the contact
gaps 3-5 are opened.
A070789 V1 EN
Figure 11: Output contact
Section 3
Basic functions
35