ABB RELION REX640 Operation Manual page 92

Section 6
Troubleshooting
86
for the internal fault. The protection relay continues to perform internal tests during
the fault situation.
If the internal fault disappears, the fault indication LEDs stop flashing and the
protection relay returns to the normal service state.
The self-supervision signal output operates on the closed-circuit principle. Under
normal conditions, the protection relay is energized and the contact gap 3-5 in slot B
is closed. If the auxiliary power supply fails or an internal fault is detected, the contact
gap 3-5 is opened.
GUID-C9AF791D-D8F6-4768-A6D9-12FD192129CD V1 EN
Figure 83: Output contact
The internal fault code indicates the type of internal relay fault. When a fault appears,
the code must be recorded so that it can be reported to ABB customer service.
More details about the active internal fault are found on the Relay Status page. On the
LHMI, the internal fault state is indicated with a red LED. More information about the
fault and recovery options can be accessed by tapping More Information.
1MRS759118 A
REX640
Operation Manual