Two Step Undervoltage Protection Uv2Ptuv (27) - ABB REL650 Applications Manual

1MRK 506 334-UUS A
Section 8
8.1
8.1.1
8.1.2
Application manual
Voltage protection

Two step undervoltage protection UV2PTUV (27)

Identification
Function description
Two step undervoltage protection
Application
Two-step undervoltage protection function (UV2PTUV ,27) is applicable in all situations,
where reliable detection of low phase voltages is necessary. It is used also as a supervision
and fault detection function for other protection functions, to increase the security of a
complete protection system.
UV2PTUV (27) is applied to power system elements, such as generators, transformers,
motors and power lines in order to detect low voltage conditions. Low voltage conditions
are caused by abnormal operation or fault in the power system. UV2PTUV (27) is used in
combination with overcurrent protections, either as restraint or in logic "and gates" of the
trip signals issued by the two functions. Other applications are the detection of "no
voltage" condition, for example, before the energization of a HV line or for automatic
breaker trip in case of a blackout. UV2PTUV (27) is also used to initiate voltage correction
measures, like insertion of shunt capacitor banks to compensate for reactive load and
thereby increasing the voltage. The function has a high measuring accuracy to allow
applications to control reactive load.
UV2PTUV (27) is used to disconnect apparatuses, like electric motors, which will be
damaged when subject to service under low voltage conditions. UV2PTUV (27) deals
with low voltage conditions at power system frequency, which can be caused by the
following reasons:
IEC 61850 IEC 60617
identification identification
UV2PTUV
3U<
SYMBOL-R-2U-GREATER-THAN
V2 EN
Section 8
Voltage protection
ANSI/IEEE C37.2
device number
27
255