ABB RET 670, Operator'S Manual

Page: 63 / 96

11.6 Function status
11.6.1 Overview
In the Function status section of the Test menu, data useful to the user in Test mode
can be found. The information available here is not limited to test applications alone
and provides information about the system as a whole.
11.6.2 View differential protection values
The quantities and measurements for transformer differential protection are accessed
via the HMI paths provided below. The measurement outputs shown here include
various trip and start signals. The magnitude of the 2nd and 5th harmonic differential
currents as well as the fundamental differential current are shown here. Restricted
earth fault protection data such as the magnitude of currents and fault detection
indications can be viewed.
11.6.2.1 Transformer differential protection, two winding (PDIF, 87T)
Test/Function status/Differential protection/TransDifferential2Wind/
T2WPDIF
Displays up to two instances of T2WPDIF with 37 measured values each. The data
available here ranges from the general common trip signal to the magnitude of the
bias current. The magnitude of the second and fifth harmonic differential current for
all three phases, block signals and start signals make up the bulk of the data presented
in this view.
11.6.2.2 Transformer differential protection, three winding (PDIF, 87T)
Test/Function status/Differential protection/TransDifferential3Wind
Displays up to two instances of T3WPDIF with 37 measurements per instance. The
data output here is identical to that shown in section
"Transformer differential
protection, two winding (PDIF, 87T)" of this document.
11.6.2.3 Restricted earth fault protection (PDIF, 87N)
Test/Function status/Differential protection/Restricted Earth Fault/REFPDIF
Displays up to three instances of REFPDIF with 10 measurements per instance. The
data available for this function includes Trip by the restricted earth fault protection
function, start, operation of directional criteria due to internal fault, block due to
second harmonic, start of switch onto fault, activation of second harmonic analysis,
various fault detection indicators and the magnitude various current values.
Section 11
Test the IED
RET 670 Operator's manual
1MRK504049-UEN rev. D
59