Siemens 7SR210 Argus Quick Start Manual page 4

alternative settings for a limited period. The feature resets
when either the circuit breaker has been closed for a settable
period, or if the current has reduced beneath a set level for a
user set period.
21FL Fault Locator
The relay provides a basic single-end type fault locator which
is able to estimate the fault position using analogue infor-
mation measured by the relay at one end of the protected
circuit during the short duration of the fault.
21LB Load Blinder
Load Blinders are used with overcurrent elements to block
tripping during periods of high reverse load currents that can
occur in distribution networks. The blinder is operated dur-
ing user defined load conditions and is used in conjunction
with the relay protection elements.
50AFD Arc Flash Detector
The 7SR2 relays can be used with the 7XG31 ReyArc range of
Arc Flash Detection devices. Arc fault protection is a tech-
nique employed for the fast clearance of arcing faults on
busbars, within metal clad switchgear & associated cable
boxes. The arc is detected using an optical sensor & the sig-
nal input to a protection device which also monitors the load
current on the system. A trip signal can be achieved in less
than 10 ms using arc detection only or within 20 ms when
using overcurrent check.
Programmable User Logic
The user can map Binary Inputs and Protection operated
outputs to Function Inhibits, Logic Inputs, LEDs and/or Binary
Outputs. The user can also enter up to 16 equations defining
scheme logic using standard functions e.g. Timers, AND/OR
gates, Inverters and Counters. Each Protection element out-
put can be used for Alarm & Indication and/or tripping.
Circuit Breaker Maintenance
Two circuit breaker operations counters are provided. The
Maintenance Counters record the overall number of opera-
tions and the Delta Counter the number of operations since
the last reset. An I t summation Counter provides a measure
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of the contact wear indicating the total energy interrupted
by the circuit breaker contacts. Each counter has a user set
target operations count which, when reached, can be
mapped to raise Alarms/ Binary Outputs. These counters
assist with maintenance scheduling.
Function LED's
Eight or sixteen user programmable tri-colour LED's are
provided eliminating the need for expensive panel mounted
pilot lights and associated wiring. Each LED can be user set
to red, green or yellow allowing for clear indication of the
associated function's state. A slip-in label pocket along-side
enables the user to insert customised notation. A printer
compatible template is available.
Function Keys
Six user programmable function keys are available for
implementing User logic and scheme control functionality,
eliminating the need for expensive panel mounted control
switches and associated wiring. Each function key has an
associated user programmable tri-color LED (red, green,
Siemens Protection Devices Limited
yellow) allowing for clear indication of the associated
function's state. A slip-in label pocket along-side enables the
user to insert his own notation for the function Key LED
Identification. Each Function Key can be mapped directly to
any of the built-in Command functions or to the User Logic
equations.
Fig 1. Tri-colour LED's and function keys
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