GE Multilin 350 Series Instruction Manual

Also see for ML Series 350: Communications manual User manual Communications manual Instruction manual

3–6 350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUALFRONT CONTROL PANEL INTERFACE CHAPTER 3: INTERFACES52a contact and closed 52b contact. If both 52a and 52b contacts are open, due to abreaker being racked out from the switchgear, both the Breaker Open and BreakerClosed LED Indicators will be off.NOTENOTE:It is strongly recommended to detect the breaker status by using both 52a and 52bcontacts.The 350 provides also detecting the breaker status by using only one contact: either52a or 52b. However, one should be aware that in such cases, it would be impossibleto distinguish between a breaker open state and breaker racked out state, unlessanother contact from the breaker is wired to the relay.To clarify this ambiguity, the BKR CONNECTED function under SETPOINTS/S2 SYSTEMSETUP/S2 BREAKER should be programmed to an additional contact input. When thisadditional input is closed, a single 52a or 52b contact will show both breaker states.When the breaker is racked out, this additional breaker connected input should beopen. In this case, both breaker status indicators will be off.• MAINTENANCE: AmberThis LED may indicate both breaker or relay maintenance depending on theprogrammed maintenance elements. The LED will turn on upon operation of amaintenance element.3.1.5 Relay messages3.1.5.1 Target messagesTarget messages are automatically displayed for any active condition on the relay such aspickups, trips, or alarms.The relay displays the most recent event first, and after 5 seconds will start rolling up theother target messages until the conditions clear and/or the RESET command is initiated.The Target Messages can be reviewed by pressing either the MESSAGE UP or MESSAGEDOWN key. If a RESET command is not performed but any of the other faceplatepushbuttons is pressed, the display will not show the target messages unless the usernavigates to ACTUAL VALUES > A4 TARGET MESSAGES, where they can be reviewed. If thetarget messages have not been cleared before the user presses a pushbutton differentfrom “RESET”, they will reappear on the screen after the time specified under theSETPOINTS > S1 RELAY SETUP > S1 FRONT PANEL > MESSAGE TIMEOUT setting, that will starttiming out from the last pressed pushbutton. The following shows the format of a typicalTarget Message:Figure 3-4: Typical target messageExample of a Phase IOC1 operation - phase A:Phase IOC1 function: TripA4 TARGET MESSAGESCause State: OperatePhase:▼