1MRS751802-MUM
REX 521
215
Protection Relay
Technical Reference Manual, Standard Configurations
Before the function block allows the closing of the CB, it ensures that the phase
difference remains within the setting range until the CB closes.
The command mode is used as a basic control principle of the synchro-check
function. In command mode, the synchro-check function directly uses the output
signal to close the circuit breaker. The close command for example from the HMI is
connected to the synchro-check function. When the close command is activated, the
synchro-check function checks the closing criteria and if they are fulfilled, it will
route the command to the output relay of the protection relay. In this application
example the close signal is connected to the power output PO3.
The command mode principle means that the interlocking logic related to the control
functionality will affect the synchro-check function as well. If blocking is needed it
can be carried out by using the ready-made interlocking logic, for example in a case
where the phase-to-phase voltage is missing from either side of the circuit breaker
because of the open miniature circuit breaker (MCB) of the measurement circuit.
11.3.4.
Connections
All the necessary settings for the connections and signal routings can be set via the
Relay Setting Tool or the local HMI.
11.3.4.1.
Protection signal routing
The settings for the protection signal routing can be implemented as described in the
first application example (see Section 9.1. Outgoing feeder, Basic B01).
11.3.4.2.
Indication and control connections
The connections for indication and control can be implemented as described in the
first application example (see Section 9.1. Outgoing feeder, Basic B01), except the
signals for the open and close buttons that in this example are disconnected. Local
control can be executed via the HMI according to the instructions in
REX 521
Operator’s Manual
(see Section 1.5. Related documents).
11.4.
Outgoing feeder, High H04
11.4.1.
Features
This application example describes an outgoing feeder of a single busbar including:
• Auto-reclosure function
• Overcurrent protection
• Directional and non-directional earth fault protection
• Phase discontinuity protection
• Thermal overload protection for cable or line
This application example is an optional solution for the seventh application example
(chapter 10.3), if extended earth fault protection against a cross-country fault is
required or wider range of measurements is needed.
Summary of Contents for REX 521
Page 1: ...Protection Relay REX 521 Technical Reference Manual Standard Configurations ...
Page 2: ......
Page 12: ...12 ...
Page 22: ...22 ...
Page 62: ...62 ...
Page 72: ...72 ...
Page 128: ...128 ...
Page 132: ...132 ...
Page 172: ...172 ...
Page 198: ...198 ...
Page 249: ......
