Self-Testing And Monitoring; Summary; Monitoring The Auxiliary Supply; Monitoring The Firmware - ABB REG316 4 Series Operating Instructions Manual

ABB Switzerland Ltd
6.

SELF-TESTING AND MONITORING

6.1.

Summary

The continuous self-monitoring and diagnostic features incorpo-
rated in RE. 316*4 assure high availability both of the protection
functions and the power system it is protecting. Hardware fail-
ures are signalled instantly via an alarm contact.
Special importance has been given to monitoring the external
and internal auxiliary supply circuits. The correct operation and
maintenance of tolerances of the A/D converter (both on external
c.t./v.t. input boards Type 316EA62 or 316EA63 or in the CPU
itself) are checked by making it continuously convert two
precisely known reference voltages.
The execution of the program itself is monitored by a watchdog.
Security when transferring data by serial communication be-
tween the protection and a local control and setting unit (PC) or
with a remote system (station control system) is provided by a
communication protocol with a "Hamming" distance of 4.
Special functions are provided for monitoring the integrity of the
v.t. connections and for checking the symmetry of the three
phase voltages and currents.
6.2.

Monitoring the auxiliary supply

Both the external auxiliary supply applied to the protection and
the internal electronic supplies are continuously monitored. The
supply unit is capable of bridging supply interruptions up to
50 ms. After this time, the O/P's are blocked and the unit is reset
and reinitialised.
6.3.

Monitoring the firmware

A hardware timer (watchdog) monitors the execution of the pro-
gram. Providing the program runs correctly, the timer is reset at
regular intervals. Should for some reason the execution of the
program be interrupted and the timer not be reset, the O/P's are
blocked and the unit reinitialised.
6-2
REG 316*4 1MRB520049-Uen / Rev. C