Compact current relay and
protection assemblies
RXHL 401 and
RAHL 401
1MRK 509 062-BEN
Page 4
Miscellaneous
Active setting group
Application
Different settings of protection functions
enable convenient change of network opera-
tional conditions, for example switching
between normal and emergency situations.
The user can change the active setting group
at any time, locally by means of local HMI or
by activation of the corresponding binary
input to the “ChActGrp” function.
Design
The relay has basically two sets of indepen-
dent setting groups built-in, which contain all
setting parameters for overcurrent and earth-
fault protections. The function has a binary
input signal that enables the user to change
active group and also a binary output signal
for indication of which setting group is
active.
Self-supervision
Application
The self-supervision function includes the
following functions;
• Checksum verification of ROM contents
during start-up.
• RAM verification during start-up.
• Normal micro-processor watchdog func-
tion, continuously.
• Internal communication error handler,
continuously.
An output error signal from the function is
available to configure to a binary output.
Local HMI
Application
The local HMI (Human-Machine-Interface)
serves as an information unit, presenting ser-
vice values and information from the last two
recorded disturbances. The current status of
all binary input signals are also available.
Trip value recording
Application
At power system faults the relay records the
primary trip values and they can be presented
in the local HMI.
The recorded values are always from the last
disturbance.
