3
Area of
application
(modified 97-10)
The main application area for the relay is to
protect capacitor banks intended for reactive
power compensation and filtering of the har-
monics.
The capacitor banks are usually protected
against overload produced by harmonic currents
and overvoltage caused by internal faults in the
bank. A protection against reconnection of a
charged capacitor to a live network should also
be included. All these functions can be found
in SPAJ 160 C.
An earth-fault and overcurrent protection is of-
ten used for selective network protection. In this
case an overcurrent and earth-fault protection
relay from the SPACOM-family can be con-
nected to the same current transformer as SPAJ
160 C.
Application
examples
Fig.1. Protection of a capacitor bank connected as a double-star in a distribution network with
three-phase current measurement.
2I>>
I
2I/U>
I/U<
I
N-N
e.g.
SPAA 120 C or
SPAA 121 C
SPAJ 160 C
Fig.2. Protection of a capacitor bank connected as a double-star in a distribution network with
two-phase current measurement.
3I>>
3I/U>
I/U<
I
N-N
eg.
SPAA 341 C1
SPAJ 160 C
I