ABB SPAC 531 C User Manual And Technical Description page 4

4
The feeder terminal is designed to be used for
the selective short-circuit and earth-fault pro-
tection of radial feeders in resonant earthed or
isolated neutral power systems. The protection
functions are based on an overcurrent module
type SPCJ 3C3 and an earth-fault module type
SPCS 3C4.
The control module SPTO 6D3 included in
feeder terminal indicates locally by means of
LED indicators the status of seven disconnec-
tors or circuit breakers. Further, the module
allows status information from the circuit break-
ers and the disconnectors to be transmitted to
the remote control system, and six objects to be
opened and closed over the remote control
system. The status information and the control
signals are transmitted over the serial bus. Also
local control is possible using the push buttons
on the front panel of the control module.
Auto-reclosing is integrated in the control mod-
ule. Up to five high-speed or delayed auto-
reclosures can be carried out.
Uo
Fig. 2. Basic functions of the integrated feeder terminal SPAC 531 C or SPAC 631 C
The control module measures and indicates the
three phase currents and the three phase-to-
phase voltages. Active and reactive power can be
measured via two mA inputs or by using the
internal current and voltage signals. When the
mA inputs are used, external measuring trans-
ducers are needed.
Energy can be calculated on the basis of the
measured power values or by using one input as
an energy pulse counter. The measured values
can be indicated locally and remotely as scaled
values.
The overcurrent module and the earth-fault
module measure and record the three phase
currents plus neutral current and residual volt-
age. All the measured and recorded values are
indicated locally and can be transmitted to the
remote control system over the SPA bus.
O
Ι
3I>
SERIAL
BUS
I
SIGNALLING
3
I
3
U
P
Q
E
O -> I
READY
O <-> I
Io
SPAC 531 C
SPAC 631 C
PROTECTION
- OVERCURRENT
- DIRECTIONAL EARTH-FAULT
MEASUREMENT
- PHASE CURRENTS
- PHASE-TO-PHASE VOLTAGES
- ACTIVE AND REACTIVE POWER
- ENERGY
CONTROL
- CB AND DISCONNECTOR STATUS
- LOCAL AND REMOTE CONTROL
- MIMIC DISPLAY
- INTERLOCKING
AUTOMATION
- AUTO-RECLOSING