1MRS750886-MUM
11
REU 513
User’s Guide
ABB Substation Automation
Products and Systems
B
Technical reference manual
1.
Instructions
1.1.
Application
The overvoltage and undervoltage relay REU 513 is a secondary relay that is
connected to the voltage transformers of an object to be protected. It is designed for
overvoltage and undervoltage protection and supervision in distribution substations.
Other application areas are overvoltage and undervoltage protection of generators,
motors and transformers.
The three-phase overvoltage and undervoltage stages continuously measure the
phase-to-phase voltages of the system. On detection of a fault the relay starts, trips
the circuit breaker, provides alarms, records fault data etc., in accordance with the
application and the configured relay functions.
Both the overvoltage and the undervoltage units include two protection stages: low-
set stages U> and U<, and high-set stages U>> and U<<. Each protection stage can
be given a definite-time or an inverse definite minimum time (IDMT) characteristic.
The start and operation of the high-set and low-set undervoltage stages can be
blocked when the measured voltages are under 0.2 x U
n
. Further, the operation of all
protection stages can be blocked separately by means of an external binary input
signal.
The high-set undervoltage stage can be set to operate either based on conventional
undervoltage measurement or on the calculated positive-phase-sequence voltage
U1s. Selecting the positive-phase-sequence operation automatically deselects the
conventional high-set undervoltage stage operation, and vice versa.
The operation of the stage U< can be blocked by the start of the stage U<<. The high-
set stages of the overvoltage and undervoltage units can be deselected from
operation separately.
The protection functions are independent of each other unless configured to be
dependent, and they have their own setting groups as well as data recording. The
over- and undervoltage functions use conventional voltage transformer
measurement.
Output contact matrix allows any start or trip signal from the protection stages to be
routed to the desired output contact.
