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Both the control module SPTO 1D2 and the
combined overcurrent and earth-fault module
SPCJ 4D29 measures analog signals.
The combined overcurrent and earth-fault mod-
ule measures the three phase currents and the
neutral current. The module indicates the cur-
rent values locally and can transmit the data via
the SPA bus to the remote control system. The
protection module always indicates the meas-
ured values as a multiple of the rated current of
the relay.
The control module measures five analog sig-
nals; three phase currents and active and reactive
power. The ratio of the primary current trans-
formers can be programmed into the control
module. In that way it is possible to indicate the
primary values of the phase currents.
The control module measures the active and
reactive power via two mA inputs. External
measuring transducers have to be used. The mA
signals are scaled to actual MWs and Mvars and
the data is indicated locally and can be transmit-
ted to the remote control system.
Active energy is measured in two ways; either by
calculating the value on the basis of the meas-
ured power or by using input channel 7 as a
pulse counter. In the latter case an external
energy meter with pulse output is needed. In
both cases the amount of measured energy is
displayed locally and can be transmitted to the
remote control system.
Measurement
functions
Serial
communication
The feeder terminal includes two serial commu-
nication ports, one on the front panel and the
other on the rear panel.
The 9-pin RS 232 connection on the front panel
is to be used for setting the feeder ter-minal and
programming the CB/disconnector configura-
tion, the feeder oriented interlocking and other
parameters from a terminal or a PC.
The 9-pin RS 485 connection on the rear panel
is used for connecting the feeder terminal to the
SPA bus. An optional bus connection module
type SPA-ZC 17 or SPA-ZC 21 is required.
Auxiliary power
supply
For the operation of the feeder protection and
control unit a secured auxiliary voltage supply is
needed. The power supply module SPGU__
forms the voltages required by the measuring
relay module, the control module and the input/
output module.
The power supply module is a transformer con-
nected, i.e. galvanically isolated primary and
secondary side, flyback-type DC/DC converter.
The primary side of the power supply module is
protected with a fuse, F1, located on the PCB of
the module. The fuse size is 1 A (slow).
A green LED indicator Uaux on the front panel
is lit when the power supply module is in opera-
tion. There are two versions of power supply
modules available. The secondary sides are iden-
tical, only the input voltage range is different.
The input voltage range is marked on the front
panel of the control module.
