N60 NETWORK STABILITY AND SYNCHROPHASOR MEASUREMENT SYSTEM – INSTRUCTION MANUAL
2-1
N60 Network Stability and Synchrophasor
Measurement System
Chapter 2: Product description
Product description
This chapter outlines the product, order codes, and specifications.
2.1 Product description
The N60 Network Stability and Synchrophasor Measurement System is part of the Universal Relay (UR) series of products. It
is a microprocessor-based device for load shedding and special protection schemes.
With its modular architecture, the N60 can be configured to monitor from one through five three-phase power circuits. The
relay provides a variety of metering functions, including the following: active, reactive, and apparent power on a per-phase
and three-phase basis; true RMS value, phasors, and symmetrical components of currents and voltages; and power factor
and frequency. The latter can be measured independently and simultaneously from up to six signals.
The N60 allows interfacing with other analog signals via optional transducer modules to monitor equipment temperature,
transformer tap positions, weather data, and other information.
In addition to standard communications protocols that can be exercised simultaneously and independently over a range
of communication ports, including the redundant Ethernet port, the relay supports an independent mechanism for direct,
fast, and secure digital inter-intelligent electronic device (IED) communications. This allows both reduced wiring and
development time for all local connections in a substation, as well as building wide-area protection and control schemes.
Up to 64 on/off signals can be exchanged between any two N60 devices via digital communications. The relays can be
configured in rings with up to 16 devices each using direct fiber (C37.94), G.704, and RS422 interfaces. An optional
redundant (dual-channel) communication card supports combinations of the three interfaces allowing different physical
connections in each channel. Dual-ring communication architecture can be selected for redundancy. Open ring or
crossover configurations can be utilized to increase the number of devices in the scheme.
The effective message delivery time depends of the number of other N60 devices located between the sending and
receiving IEDs. A two-cycle or one-cycle worst-case message delivery times can be comfortably achieved for
comparatively large N60 schemes.
Sophisticated self-monitoring and diagnostic functions are incorporated, such as 32-bit cyclic redundancy code (CRC),
unreturned messages count, and lost packets count. The N60 supports both multiplexed and direct fiber (up to 100 km)
inter-substation connections.
The N60 allows sending and receiving any analog value measured by the relay using the dedicated inter-IED
communication mechanisms. Power, voltage, and current magnitudes, frequency, transducer inputs and other values can
be freely configured for the inter-IED exchanges. The analog values are transmitted with the eight-bit resolution. Upon
reception, any remote analog value can be re-sent, compared with another value or a constant threshold, added to or
