Siemens 7SR23 DAD, Manual

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Chapter 1) 7SR23 DAD Description Of Operation
©2013 Siemens Protection Devices Limited Chapter 1 Page 14 of 36
2.8 Binary Outputs (Output Relays)
Relays are fitted with 8 or 16 binary outputs. All outputs are fully user configurable and can be programmed to
operate from any or all of the available functions.
The Power Supply module includes the relay basic I/O. The module includes six binary outputs each fitted with 1
contact – providing in total 1 x normally closed (NC), 2 x change-over (CO) and 3 x normally open (NO) contacts.
In the default mode of operation binary outputs are self reset and remain energised for a user configurable
minimum operate time of up to 60 seconds. If required, outputs can be programmed to operate as ‘hand reset’ or
‘pulsed’. Where an output is programmed to be ‘hand reset’ and ‘pulsed’ then the output will be ‘hand reset’ only.
The binary outputs can be used to operate the trip coils of the circuit breaker directly where the trip coil current
does not exceed the 'make and carry' contact rating. The circuit breaker auxiliary contacts or other in-series
auxiliary device must be used to break the trip coil current.
CB’Trip Contacts’ are assigned in the OUTPUT CONFIG>BINARY OUTPUT CONFIG menu. Operation of a ‘Trip
Contact’ will actuate the ‘Trip Alert’ screen where enabled and will initiate both fault record storage and CB Fail
protection where enabled.
When the relay is withdrawn from the case all normally closed contacts will be open circuited. This should be
considered in the design of the control and protection circuitry.
Notes on Self Reset Outputs
Outputs reset after the initiate condition is removed, they are subject to the user definable ‘Minimum Operate
Time’ setting.
With a failed breaker condition the relay may remain operated until current flow in the primary system is
interrupted by an upstream device. The relay will then reset and attempt to interrupt trip coil current flowing
through an output contact. Where this level is above the break rating of the output contact an auxiliary relay with
heavy-duty contacts should be utilised.
Notes on Pulsed Outputs
When operated, the output will reset after the user definable ‘Minimum Operate Time’ setting regardless of the
initiating condition.
Notes on Hand Reset Outputs
Hand reset outputs can be reset by either pressing the TEST/RESET button, by energising a suitably
programmed binary input, or, by sending an appropriate command over the data communications channel(s).
On loss of the auxiliary supply hand-reset outputs will reset. When the auxiliary supply is re-established the binary
output will remain in the reset state unless the initiating condition is still present.
Binary Output Test
The MAINTENANCE>OUTPUT MATRIX TEST menu includes a facility to test output relays from the relay fascia
without the need for a secondary injection test set.
Binary outputs can also be energised from the Reydisp Evolution software package where PC facilities are
available.