Feeder Terminal
REF 542plus
1MRS756269
6
Application
Monitoring and self-diagnosis
The REF 542plus offers several features for
monitoring the primary part as well as self-
diagnosis. The following computed quantities
are available for primary part monitoring:
•
maximum and mean currents in the obser-
vation period (0 ... 30 min)
•
sum of interrupted currents
•
operating time
•
number of switching cycles (open-close
circuit breaker)
•
spring charging time supervision (when
applicable)
•
trip coil supervision
The REF 542plus is equipped with self-diag-
nosis routines that constantly check the hard-
ware and software modules status. Every
REF 542plus binary input and output module
is equipped with a watchdog contact that trig-
gers in case of fault or power loss. This con-
tact can be used to detect unit failure and to
initiate the appropriate actions. Analog input
channels can be optionally supervised. A bro-
ken wire in the connection with an instrument
transformer or a sensor can be detected and
an alarm can be activated.
Protection
REF 542plus offers a wide range of functions
for protection. As previously mentioned, a
wide range of protection schemes for the pro-
tection of several system components can be
configured. The available protection func-
tions depend on the ordered software
licenses. The licenses are Basic Low, Basic,
Multi Low, Multi, Differential and Distance.
In table 20 the corresponding provided pro-
tection functions are listed.
Current protection:
•
inrush blocking (68)
•
overcurrent instantaneous (50)
•
overcurrent definite time, 2 thresholds
(51)
•
overcurrent directional, 2 thresholds (67)
•
overcurrent IDMT (51 IDMT)
•
earth fault, 2 thresholds (51N)
•
earth fault IDMT (51 IDMT)
•
earth-fault directional, 2 thresholds (67N)
•
earth-fault directional sensitive (67S)
•
earth-fault directional sector (67NS), 10
thresholds.
Voltage protection:
•
overvoltage instantaneous (59)
•
overvoltage definite time, 2 thresholds
(59)
•
undervoltage Instantaneous (27)
•
undervoltage definite time, 2 thresholds
(27)
•
residual overvoltage, 2 thresholds (59N)
Line protection:
•
distance protection (21)
Differential protection:
•
differential protection for motors and
transformer (87)
•
restricted earth-fault for transformer
(87N)
Thermal protection:
•
for cables, motors and transformers (49)
Motor-specific protection:
•
number of starts counting (66)
•
locked rotor (51LR)
•
motor start (51MS)
•
low load (37)
•
unbalanced load (46)
Power quality mitigation:
•
power factor controller (55)
•
switching resonance protection
•
high harmonics protection
Other protections and related functions:
•
frequency protection (81), 6 thresholds
per net
•
synchro check (25)
•
fault recorder
•
autoreclosure (79)
•
directional power (32).
At most 24 protection functions can be
installed inside the REF 542plus unit. The
maximum number is anyway dependent upon
the available processing power.
Summary of Contents for REF 542plus
Page 1: ...Feeder Terminal Product Guide REF 542plus...
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