CHAPTER 6: SETPOINTS
S5 INPUTS/OUTPUTS
350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
6–159
Output relays
The 350 relay is equipped with seven electromechanical output relays: two special relays
designated for Breaker Trip and Close (Relay 1 “Trip”, Relay 2 “Close”), four general purpose
relays (Auxiliary Relays 3 to 6), and one Critical Failure relay for fail-safe relay indication.
The special purpose relays have fixed operating characteristics and the general purpose
relays can be configured by the user. Logic diagrams for each output relay are provided
for detailed explanation of their operation.
Operation of these breaker-control relays is designed to be controlled by the state of the
circuit breaker as monitored by a 52a or 52b contact.
•
The Trip and Close relays reset after the breaker is detected in a state corresponding
to the command. When a relay feature sends a command to one of these special
relays, it will remain operational until the requested change of breaker state is
confirmed by a breaker auxiliary contact and the initiating condition has reset.
•
If the initiating feature resets, but the breaker does not change state, the output relay
will be reset after a default interval of 2 seconds.
•
If neither of the breaker auxiliary contacts, 52a nor 52b, is programmed to a logic
input, the Trip Relay is de-energized after either the delay programmed in the Breaker
Failure feature, or a default interval of 100 ms after the initiating input resets. The
Close Relay is de-energized after 200 ms.
•
If a delay is programmed for the Trip or Close contact seal-in time, then this delay is
added to the reset time. Note that the default setting for the seal-in time is 40 ms.
Output Relay 1 "Trip"
The following path is available using the keypad. For instructions on how to use the
keypad, please refer to
Chapter 3 - Working with the Keypad
.
PATH
:
SETPOINTS > S5 INPUTS/OUTPUTS > OUTPUT RELAYS > RELAY 1 TRIP
SEAL IN TIME
Range: 0.00 to 9.99 s in steps of 0.01
Default: 0.04 s
This setting defines the time to be added to the reset time of the Relay 1 Trip output,
thus extending its pulse width. This is useful for those applications where the 52 contacts
reporting the breaker state are faster than the 52 contacts that are responsible for
interrupting the coil current.
BLOCK RLY 1 TRIP
For details see
This setting defines a block to the Trip Output relay. When the selected input is asserted,
the Trip Output relay will be blocked.
52a Contact
Configured
52b Contact
Configured
Relay Operation
Yes
Yes
Trip Relay remains operational until 52b indicates an
open breaker. Close Relay remains operational until 52a
indicates a closed breaker.
Yes
No
Trip Relay remains operational until 52a indicates an
open breaker. Close Relay remains operational until 52a
indicates a closed breaker.
No
Yes
Trip Relay remains operational until 52b indicates an
open breaker. Close Relay remains operational until 52b
indicates a closed breaker.
No
No
Trip Relay operates until either the Breaker Failure delay
expires (if the Breaker Failure element is enabled), or 100
ms after the feature causing the trip resets. Close Relay
operates for 200 ms.