Time Settings; Self-Supervision; Internal Faults - ABB RELION 620 Series Technical Manual

Basic functions
3.1.19

Time settings

Table 25: Time settings
Parameter Values (Range)
Time format
1=24H:MM:SS:MS
2=12H:MM:SS:MS
Date format
1=DD.MM.YYYY
2=DD/MM/YYYY
3=DD-MM-YYYY
4=MM.DD.YYYY
5=MM/DD/YYYY
6=YYYY-MM-DD
7=YYYY-DD-MM
8=YYYY/DD/MM
3.2

Self-supervision

The protection relay's extensive self-supervision system continuously supervises
the relay's software, hardware and certain external circuits. It handles the run-time
fault situation and informs the user about a fault via the LHMI and through the
communication channels. The target of the self-supervision is to safeguard the
relay's reliability by increasing both dependability and security. The dependability
can be described as the relay's ability to operate when required. The security can be
described as the relay scheme's ability to refrain from operating when not required.
The dependability is increased by letting the system operators know about the
problem, giving them a chance to take the necessary actions as soon as possible.
The security is increased by preventing the relay from making false decisions, such
as issuing false control commands.
There are two types of fault indications.

• Internal faults

• Warnings
3.2.1 Internal faults
When an internal relay fault is detected, the relay protection operation is disabled,
the green Ready LED begins to flash and the self-supervision output relay is de-
energized, i.e. the change-over contact is released.
An indication about the fault is shown as a message on the LHMI. The text
Internal Fault with an additional text message, a code, date and time, is shown
to indicate the fault type.
68
Unit
Internal fault indications have the highest priority on the LHMI. None of
the other LHMI indications can override the internal fault indication.
Step Default
1=24H:MM:SS:MS
1=DD.MM.YYYY
1MRS757644 H
Description
Time format
Date format
620 series
Technical Manual