Siemens Protection Devices Limited 4
Circuit Breaker Maintenance
A circuit breaker operations counters is provided.
A summation of I
2
broken by the circuit breaker provides a
measure of the contact erosion.
Operations count and I
2
alarm levels can be set which, when
reached, can be used as an input to a condition-based mainte-
nance regime.
Directional Control
7SG112n (Argus 2) and 7SG116n (Argus 6) only.
Directional elements are available as an ordering option.
The bi-directional elements provide independent settings for
each direction of each overcurrent stage. Single phase or two-
out-of-three directional decisions are available for the phase-
fault elements. On some models the characteristic angle for
phase-fault and earth-fault are freely selectable, while on oth-
ers they are chosen from +30° and +45° for phase-fault, and
from 0°, -15°, -45° and -65° for earth-fault.
The polarising voltage for phase-fault elements is taken from
the quadrature phase-phase voltage - see the typical connec-
tion diagrams for details.
Cold Load Pickup
7SG114n (Argus 4) and 7SG116n (Argus 6) only.
The relay can apply higher current settings with longer time
delays, after the circuit breaker has been open for a program-
mable time.
When the circuit breaker is closed, these higher settings are
applied for a programmable time, or until the measured cur-
rent has fallen to normal levels.
Auto-Reclose
7SG114n (Argus 4) and 7SG116n (Argus 6) only.
Integrated auto-reclose is available as an ordering option.
The relay incorporates a 5 trip/4 close auto-reclose sequence
that can be initiated by an internal or external signal.
For each type of protection trip – phase-fault, earth-fault, SEF
and external – a separate sequence of instantaneous and de-
layed trips is available. Programmable dead times and reclaim
times with a wide setting range and integrated sequence co-
ordination enable virtually all distribution auto-reclose
schemes to be realised.
For full technical data refer to the Performance
Specification of the Technical Manual.
Characteristic energising quantity
AC Current/Voltage Frequency
1A / 5A
63.5/110V
50 / 60Hz
Current Inputs: Burdens
5A Phase/Earth < 0.2VA
1A Phase/Earth < 0.05VA
5A SEF/REF < 0.4VA
1A SEF/REF < 0.2VA
Phase/Earth Current Inputs: Thermal Withstand
Continuous
3.0 x In
10 minutes
3.5 x In
5 minutes
4.0 x In
3 minutes
5.0 x In
2 minutes
6.0 x In
1A Input 5A Input
3 Second 57.7A 230A
2 Second 70.7A 282A
1 Second 100A 400A
I Cycle
177A 618A
SEF/REF Current Inputs: Thermal Withstand
Continuous 2.0 x In
10 minutes 3.5 x In
5 minutes 4.0 x In
3 minutes 5.0 x In
2 minutes 6.0 x In
1A Input 5A Input
3 Second 37.5A 202A
2 Second 46A 247A
1 Second 65A 350A
I Cycle 120A 618A
Voltage Inputs
Burden < 0.1VA at 110V
Continuous Withstand 250V
DC Auxiliary supply
Rated DC Voltage Operating Range V dc
24/30/48V 18 to 60V
110/220V 88 to 280V
Operate State Burden
Quiescent (Typical) 3 W
Maximum 10 W
Allowable superimposed ac
component
≤ 12% of dc
voltage
Allowable breaks/dips in
supply (collapse to zero from
nominal voltage)
≤ 20 ms
Inputs and Outputs
Technical Data
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