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Factory Logic Anthony Rahiminejad NTRODUCTION The SEL-849 Motor Management Relay offers advanced low-voltage motor protection in a compact and economical design, but it can also be used to provide basic feeder protection for a variety of applications. This application guide demonstrates how to configure the SEL-849 to provide overcurrent protection for a feeder protection application.
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Step 2 Open an Internet browser and type the SEL-849 default IP address (169.254.0.1) into the URL address bar, as shown in Figure 2. Figure 2 SEL-849 IP Address Step 3 Select 2AC: View and Change in the Access Level tab. Type the default password OTTER into the ACC Password field and TAIL into the 2AC Password field.
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Rogowski coil current transformers (CTs). External CTs must be used, where the external CT leads are passed through the CT inputs of the SEL-849. When using external CTs, divide the CT primary by the CT secondary. Enter this value into Phase CT Ratio 1 (CTR1). If a core balance CT is used for ground fault sensing, Core Balance CT Ratio (CTRN) should be set equal to the core balance CT ratio, and modifications to the factory logic will be required.
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Instantaneous Overcurrent menu and setting Residual IOC 1 Pickup (50G1P) and Residual IOC 1 Delay (50G1D). The phase and residual instantaneous overcurrent settings should be determined by a power system protective device coordination study. Figure 6 Instantaneous Overcurrent Settings SEL Application Guide 2015-33 Date Code 20151102...
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Figure 7 Time-Overcurrent Settings Step 9 Verify the new settings, and click Submit Changes at the bottom of the page. The SEL-849 is now configured for basic feeder protection. ONCLUSION This application guide demonstrates how to configure the SEL-849 to provide basic feeder protection for a 480 V switchboard using factory logic and settings provided by a protective device coordination study.
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