GENERAL
10
NA30 - Manual - 04 - 2022
2 G E N E R A L
2 G E N E R A L
Preface
The relay type NA30 can be used in radial networks as feeder or power transformer protection:
• On long feeders in ungrounded or Petersen coil and/or high resistance grounded systems.
• On the BT side of parallel connect transformers that are protected with differential element with
any grounded systems.
• As ground fault protection of parallel connected generators or generator-transformer unit on the
same Busbar.
Following input circuits are available:
• Three phase current and one residual current inputs with nominal currents independently select-
able at 1 A or 5 A using dip-switch.
• One residual voltage input with nominal voltage programmable in the range 50...130 V (
U
ER
=100V).
• Five binary inputs.
• One block input (logic selectivity).
In addition to the main protection element, the breaker failure (BF), CT monitoring (74CT)) and Trip
Circuit Supervision (TCS) are also provided.
Setting, programming and reading operations must be effected by means of Personal Computer with
ThyVisor software or by means of remote communication interface (RS485 bus,Ethernet network and
USB); all operations must be performed through MMI.
According to the hardware configurations, the NA30 protection relay can be shipped in various case
styles depending on the required mounting options:
• Flush.
• Projecting mounting.
• Rack.
• With separate operator panel.
Other options are:
• Auxiliary power supply operating range.
• Communication protocols.
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