10
10
GENERAL
NC2 0 - Manual - 01 - 2015
2 GENERAL
Preface
The relay type NC20 provides protection of shunt capacitor banks and harmonic fi lter circuits.
The capacitor banks may have the following confi gurations:
Single Wye grounded.
Single Wye ungrounded (with a resistor on the output of the neutral unbalance voltage transformer
in order to develop the appropriate input current for the unbalance protection).
Double Wye ungrounded.
The capacitor banks may be: internally/externally fused or fuseless capacitor units.
A suitable compensation method is provided to compensate the inherent unbalance neutral cur-
rent.
Following input circuits are available:
Three phase current and one neutral unbalanced current inputs with nominal currents indepen-
dently selectable at 1 A or 5 A using dip-switch.
Three phase voltages (line-to-ground) with nominal voltages programmable in the range 50...130 V
(U
R
=100V) .
Two binary inputs.
One block input (logic selectivity).
In addition to the main protection element, the breaker failure (BF), CT monitoring (74CT), Trip Circuit
Supervision (TCS) and Programmable Logic controller (PLC) are also provided.
Setting, programming and reading operations must be effected by means of Personal Computer with
ThySetter software or by means of remote communication interface (RS485 bus and Ethernet net-
work); all operations must be performed through MMI.
According to the hardware confi gurations, the NC20 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.
Photo
•
•
•
•
•
•
•
•
•
•
To Next Page
Loading...
Need help?
General
