Megger TDS40, Руководство по эксплуатации, Страница: 66 / 71

7-66
Code Cl. Operational
message
Description Input
19 N Jumper
changed
Jumper coding of module
"Control node VLF…"
has been changed during
operation.
Undo changes or make
changes only when
system is switched off
20 N Module coupling The connection between
the modules of the sys-
tem has been interrupted.
Restore connection,
check hardware signal
COUPL on module
21 N SF6 pressure
The SF6 gas pressure in
the HV switching system
is below limit.
Gas pressure monitor at
present not functional,
check hardware signal
PRESS on module
22 N GND SWITCH
OPEN
Danger! The system
cannot ensure proper
earth protection.
(only 80 kV systems)
Manually discharge by
external means, check
return and control lines to
discharge switches
23 N Feed switch on At least one of either
charge switches has not
opened.
Check control of either
charge switches and
hardware signal XXXn on
module
24 N Dischg. switch The discharge switch has
not opened.
Check control of
discharge switch and
hardware signal XXXn on
module
25 N HV source on Return message from a
switched-off HV source
reports source switched
on.
Check HV sources, their
mains lines as well as
hardware signals
N/PISON on module
26 N HV source(s) ! The return messages
expected from either HV
sources have broken
down or are wrong.
Check HV sources, their
mains fuses and
hardware signals
N/PISON on module
27 N Coil overload Current monitor in slave
reports overcurrent
through the VLF ring-
around coil.
Reduce load at HV output
of system or magnitude
of high voltage
28 N HV po Polarity monitor in slave
reports wrong (positive)
polarity at HV measuring
divider.
Check operation of HV
thyristors (ring-around
may have not taken
place)
29 N HV polarity - Polarity monitor in slave
reports wrong (negative)
polarity at HV measuring
divider.
Check operation of HV
thyristors (ring-around
may have not taken
place)