Woodward SEG HighPROTEC MRA4, Device Manual

Page: 467 / 510

VTS-Supervision Module - Voltage Transformer Supervision [ANSI 60FL]
VTS-Supervision Module - Voltage Transformer
Supervision [ANSI 60FL]
Available stages:
VTS
Supervision of the voltage transformers (VTs) by a digital input
The module »VTS« is capable of detecting a fuse failure at the secondary side of the VTs as long as the
automatic circuit breakers of the VTs are connected with the device via a digital input and if this input is assigned
to the module »VTS« .
Supervision of the VTs by comparing the measured and calculated residual voltage
The module »VTS« can detect a VT failure if the calculated residual voltage does not match the measured one.
As a precondition, however the phase voltages (not the line-to-line voltage) are connected to the device and so
the residual voltage can be calculated. It is furthermore necessary that the residual voltage is actually being
measured by means of the VTs auxiliary windings (e-n).
If an adjustable threshold value (difference between measured and calculated residual voltage) has been
exceeded, a VT failure can be assumed. This will then be signaled by an alarm/message.
EN MRA4 04/09 Page 467