Siemens 7UT51

7UT51 v3
Protecting an Additional Device or Equipment
11
PRIM-2330C 117
11 Protecting an Additional Device or Equipment
A 7UT513 relay has three sets of phase-current inputs
that enable it to protect an object with three windings
or branches. An alternative application is to use a
7UT513 relay to protect a two-winding (or two-branch)
object, and use the relay’s third set of phase-current
inputs to protect a separate, additional device or
equipment.
The relay’s time overcurrent function, and/or either
thermal overload element can protect this virtual
object instead of the object being protected by the
differential element. Likewise, the ground-current CT
inputs of a 7UT513 can be used to provide tank
leakage protection of a virtual object (providing that
the tank leakage option was ordered). If this feature is
used, the virtual object must be described using the
settings described in this section.
1401 In VIRT OB
Rated nominal current of the additional protected object.
Range: 1
–
100,000 A
Default: 2,000
1402 In CT
Rated nominal primary current of the CTs monitoring
the phase currents of the additional protected object.
Range: 1
–
100,000 A
Default: 2,000
1404 In CT STPT
Rated nominal primary current of the CT monitoring the
ground current of the additional protected object.
Range: 1
–
100,000 A
Default: 2,000
1405 CT STARPT
Orientation of CTs monitoring the additional protected
object.
Option Description
SAME SIDE The CT common points are on the same
side of the additional protected object.
OPPOSITE
SIDES
The CT common points are on the opposite
sides of the additional protected object.