Key Technical Specifications
- Product Model: SR489-P1-HI-A20-E-H
- Manufacturer: GE Multilin
- Power Supply: 70–265 VAC / 90–300 VDC
- CT Input: 5 A nominal; VT input for generator terminal voltage
- Frequency Range: 48 Hz to 62 Hz
- Protection Elements: Stator differential, reverse power, loss of excitation, negative sequence, over/under frequency, 100% stator ground
- Communication: RS232 front port, rear RS485, 10Base-T Ethernet; Modbus RTU, Modbus TCP, DNP3.0
- Event Recording: IRIG-B time-synchronized SOE and oscillographic waveform capture
- Output Contacts: 6 form-C relay outputs (trip, alarm, auxiliary and self-test)
- Operating Temperature: -40 °C to +60 °C
- Enclosure Rating: IP40 front panel, IP10 rear terminals
- Mounting: Panel drawout assembly
- Compliance: IEC 60255, ANSI protective element curves
Product Introduction
This GE SR489-P1-HI-A20-E-H is a drawout generator management relay for synchronous and induction generators. It combines protective tripping, power metering, sequence-of-events logging and local HMI in one unit.
The relay supports ANSI, IEC and custom FlexCurve overcurrent characteristics. It shorts CT circuits automatically during withdrawal, so CT secondary circuits remain safe while swapping the relay.
Installation & Configuration Guide
Preparation (10 min)
- Isolate AC/DC control power and open generator breaker lockout tags.
- Gather screwdrivers, CT/VT wiring drawings, and GE EnerVista software on a laptop.
- Photograph all rear terminal wiring before removal.
- Confirm the replacement model CT rating matches the existing relay.
Removal (5–10 min)
- Confirm generator is offline; verify no live high-voltage circuits remain.
- Release the drawout latch and pull the relay partially outward. CT shorting contacts engage automatically.
- Unplug rear wiring terminal block and fully extract the unit.
Installation (10 min)
- Slide the replacement relay into the panel drawout chassis.
- Reconnect the rear terminal block following the photo reference.
- Push the relay fully seated and lock the drawout latch.
- Connect the front RS232 port to a laptop for setpoint upload.
Power-On & Test (10 min)
- Restore control power and inspect front panel LED status.
- Use EnerVista to read existing setpoints and verify element configuration.
- Run built-in element simulation to test trip and alarm outputs.
- Clear fault records and confirm SOE and waveform capture functions.
Troubleshooting Quick Reference
- Relay no power / blank display: Check DC/AC control supply. Verify fuse integrity on control power circuit.
- CT alarm active: Inspect CT wiring for open circuits. Confirm drawout CT shorting contacts release when fully seated.
- Communication timeout: Check Ethernet cable or RS485 termination. Confirm baud rate and station address match host SCADA.
- Spurious trip on generator start: Review pickup settings for negative sequence or loss-of-excitation elements.
- Waveform capture fails to trigger: Verify event trigger logic and memory allocation inside EnerVista.
Dimensions, Mounting & Wiring Notes
- H×W×D: 292 mm × 178 mm × 210 mm
- Mounting method: Panel drawout chassis, cutout mount for generator control cabinets
- Terminal notes: CT secondary wiring must be twisted pair. Do not open CT circuits while primary current flows. Use shielded cable for IRIG-B time sync wiring.
FAQ
Q: Can this relay protect both synchronous and induction generators? A: Yes. It supports both machine types, but setpoint logic must be adjusted for the generator type.
Q: What condition will my unit arrive in? A: Available stock is Refurbished (Tested). Every unit passes our full SOP test sequence before shipment. Factory sealed new original stock is not available.
Q: Can I hot-swap this relay while the generator remains online? A: The drawout design shorts CTs during extraction, but site safety procedures usually require the generator to be offline before relay removal. Follow your plant lockout rules.
Q: I’m replacing an old 489 relay. Do I reuse the old setpoints? A: You can export setpoints from the old unit via EnerVista, then upload to the replacement. Always perform element simulation after upload.
Q: What happens if CT leads are opened while the generator is energized? A: Dangerous high voltage appears on CT secondary. The relay has CT supervision alarms, but supervision does not eliminate the hazard.
Q: What is the risk of ESD damage during handling? A: High. Static discharge can damage internal measurement circuits without visible burn marks. Always wear a grounded wrist strap when handling the relay PCB.
