Product Scope; Cip - GE MiCOM P747 Agile Technical Manual

MiCOM P747
We would like to highlight the following changes of nomenclature however:
● The word 'relay' is no longer used for the device itself. Instead, the device is referred to as an 'IED'
(Intelligent Electronic Device), the 'device', the 'product', or the 'unit'. The word 'relay' is used purely to
describe the electromechanical components within the device, i.e. the output relays.
● British English is used throughout this manual.
● The British term 'Earth' is used in favour of the American term 'Ground'.
2.4

PRODUCT SCOPE

This product protects busbars with up to 4 zones plus a check zone. It can be applied at any voltage level.
One device is used to protect each phase (3-box solution). A further device can be used to protect the
neutral line (4-box solution). The device is suitable for applications on solidly grounded systems, or where a
centralised scheme is needed.
Each device can manage a maximum of:
● 4 Voltage transformers (VTs) (1 VT per zone),
● 18 Current transformers (CTs)
● 18 Circuit breakers (CBs)
● 72 isolators
● Up to 40 Digital Inputs and 128 Virtual Inputs (128 digital inputs via communications) for each
protected phase
● Up to 32 Digital Outputs and 128 Virtual Outputs (128 digital outputs via communications) for each
protected phase
The P747 consists of the following main components.
Main protection
This uses low impedance biased current differential protection. The typical operating time is less than one
cycle. If a fault occurs and more than one zone needs to be tripped, you might need to trip zones
sequentially. You can do this by setting different time delays on each of the zone differential elements.
Backup protection
This consists of:
● phase overcurrent
● dead zone
● circuit breaker failure
Settings application software
This allows you to create a scheme and display the measured data. The scheme editor allows you to quickly
draw schemes from a library of elements, then validate the scheme. It can also display the status of DDBs
and measured data on the scheme in real time.
Inputs and outputs
The device has many hard-wired digital inputs and outputs. For applications that demand more, virtual inputs
and outputs can be used between the products protecting the different phases. 128 virtual inputs and outputs
can be shared between products using communications links. Use hard-wired inputs and outputs to connect
the most time-critical signals between devices. Use Virtual inputs and outputs to communicate less time-
critical information signals between devices.
P747-TM-EN-1
P747-TM-EN-1.1
Chapter 1 - Introduction
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