Basic Functions

Self Supervision

The IED is provided with an extensive self-supervision system which continuously 

supervises the software and the electronics. It handles run-time fault situations and 

informs the user about an existing fault via the LHMI and the communication. 

When in an IED internal fault is detected, the green Ready LED ceases to glow and the 

self-supervision output contact is activated. Internal fault indications have the highest 

priority on the LHMI. None of the other LHMI indications can override the internal fault 

indication. An indication about the fault is also shown as a message on the LHMI. 

The text IRF with an additional text message, a code is shown to indicate the fault type. 

The user can try to eliminate the fault by restarting the IED. 

If the fault is still found, the IED stays in internal fault mode. 

All other output contacts are released and locked for the internal fault. 

The IED continues to perform internal tests during the fault situation.

If an internal fault disappears, the green Ready LED starts glowing and the IED 

returns to the normal service state. The fault indication message remains on the LCD until manually cleared.

The self-supervision signal output operates on the closed circuit principle.

Under normal conditions the relay is energized and the contact gap 5-6 in connector XK2 is closed.

If the auxiliary power supply fail or an internal fault is detected, the contact gap 5-6 is opened.