GE Consumer & Industrial - G E Power Controls

3.2.12 Current measurement system (Code 6)
3.2.13 Electronic control system
The SEL current measurement system consists of the
sensing component (1) and signal-processing unit (2)
[Fig.17]. SEL sensor is integrated into a specially shaped
upper terminal of the breaker and is connected by a
shielded cable to the signal-processing unit. SEL control
unit is placed in the control-box [Fig. 18].
All the control PCBs are installed in control box [Fig. 18].
Starting from the left, these are:
Fig. 17 SEL current measurement system
SEL may be used for recording DC currents in selected
measurement ranges of 6 kA or 12 kA. Measurement of
rated current values and of the current rise may now be
made directly at the breaker.
The sensor includes Hall-probes and delivers a
proportional signal-output to the SEL control. The signalprocessing
unit transforms input signal, into standard
output signals shown in the table below.
The outputs are insulated from the main voltage. The
insulation withstands voltages up to 4 kV RMS and up to
40 kV in peak.
Two versions are available. Standard model (T35) for
ambient temperature –5 °C…+35 °C and the model for
higher temperature (T55) –5 °C…+55 °C.
More details can be found in separate instruction for SEL
usage.
Type SEL 06-1 06-2 06-4 12-1 12-2 12-4
Input - 6 kA…+6 kA -12 kA…+12 kA
U Ne [V] 1000 2000 4000 1000 2000 4000
T35
for ambient temperature of the breaker
-5 °C…+35 °C / +23 °F…+95 °F
Fig. 18 Control box with control units
(1) NEKO control unit [Fig. 19-1] (Code 12) – internal
control unit with capacitor bank. Releases firing signal for
ED coil (-X2 :10/:11) and provides indication of the
capacitors charging (-X3 :6/:7). NEKO control unit also
blocks the firing signal until C-bank is fully charged
(~15 sec).
WARNING: NEKO unit requires a high quality firing signal.
Be sure, that voltage level is between 8 V…24 V DC and
there are no short spikes on signal (