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CHAPTER 6: SETPOINTS
Output Relays -
Breaker - Input/
Output "E"
339 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL
When the setting
S2 SYSTEM SETUP > SWITCHING DEVICE
output relays function as:
Output Relay 1: Breaker Trip
Output Relay 2: Breaker Close
Output Relay 3: Start Inhibit
Output Relays 4 to 6: Auxiliary Relays
Output Relay 7: Critical Failure
There are four special purpose relays: Breaker Trip, Breaker Close, Start Inhibit, and Critical
Failure. These relays have fixed operating characteristics:
Breaker Trip: Seal-in
Breaker Close: Seal-in
Start Inhibit: Self-reset
Critical Failure: Self-reset
The user can configure an Auxiliary Relay as either latched or self-reset. Logic diagrams
for each Output Relay are provided for detailed explanation of their operation.
Operation of the BREAKER TRIP and BREAKER CLOSE relays is 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.
52a Contact
52b Contact
Configured
Configured
Yes
Yes
Yes
No
No
Yes
No
No
is selected as BREAKER, the seven
Relay Operation
Trip Relay remains operational until 52b indicates an
open breaker. Close Relay remains operational until 52a
indicates a closed breaker.
Trip Relay remains operational until 52a indicates an
open breaker. Close Relay remains operational until 52a
indicates a closed breaker.
Trip Relay remains operational until 52b indicates an
open breaker. Close Relay remains operational until 52b
indicates a closed breaker.
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.
S5 INPUTS/OUTPUTS
6–147
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