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292
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Germany (0 91 87) 10-0 - USA (847) 827-7600 - UK (01296) 420336 - www.etacbe.com
Issue C
Operating status
Fault-free
operation
Short-circuit Wire break
of the load
Control input U
S
YELLOW LED -
control current
GREEN LED -
load current monitoring
Auxiliary contact
Remarks
“0”
0
“1”
1
“1”
1
“0”
0
“1”
1
0
1
0
0
0
open
load
open closed
load
circuit breaker
open open
OFF ON tripped
In principle, the E-T-A SSRPC E-1071-073 operates like conventional
electro-mechanical relays, with additional protective and signal functions.
The control input replaces the magnetic coil and the power transistor
replaces the main contact.
Control circuit
The control current flows through the LED and the opto coupler
immediately a voltage higher than 8.5 V is applied at the input terminals
(6 and 7). The opto coupler transmits the signal to the load circuit, at the
same time switching the load transistor on. This signal is transmitted as
a status signal to all monitoring circuits. The input protection diode
protects the control voltage from incorrect polarization. Control current
limitation is provided by a constant current diode.
Load circuit
The load circuit is switched ON or OFF according to the control signal
(“0” or “1”), with electronic circuits monitoring the load circuit for faults
such as overload or short-circuit. Should one of these faults occur, the
monitoring circuitry will immediately react, causing the load transistor
to disconnect and the circuit breaker to trip. Transistor disconnection
occurs according to the storage time characteristics. The storage time
increases noise immunity avoiding disconnection of non-harmful peaks
such as those caused by inrush currents from lamp load connection.
Storage time is not a constant quantity but is inversely proportional to
the overcurrent factor.
Status indication
Status indication is provided by 2 LEDs (yellow and green) on the front
of the housing.
YELLOW LED = correct control voltage
The LED indicates when the control voltage is higher
than 8.5 V, with control current flowing.
GREEN LED =
correct load current
The green LED indicates when the load current is
higher than 0.2 A.
Faults such as too high a load resistance, wire break, poor contact, or
overload/short-circuit, are available when only the yellow LED indicates.
SSRPC E-1071-073 includes two current measuring terminals (2 mm
dia.) on the front. These terminals provide for load current measurement
in terms of voltage drop at the 0.1 shunt in the load circuit.
Technical description
Operating modes
1 = LED indicates
0 = LED does not indicate
Solid State Remote Power Controller E-1071-073
Storage time characteristic curve
t
(theoretical overcurrent factor)
I
N
2
10
100
5
3
1000
4
5 x I
N
current limitation
20