Model Interpretation

SR489: 489 series generator management relay

P5: 5 A CT secondary phase current input

LO: Low‑voltage control power (20–60 VDC / 20–48 VAC, 48–62 Hz)

A20: 4 isolated 4–20 mA analog outputs

E: Enhanced front panel (40‑character LCD, no Ethernet)

Technical Parameters

Input & Power

CT Input: 5 A phase (5 channels); 2 ground CT inputs

VT Input: 0–690 V (delta/wye configurable)

Control Power: 20–60 VDC / 20–48 VAC, 48–62 Hz

Power Consumption: ≤8 VA typical

Protection Functions

Stator: Overload (thermal memory), phase overcurrent (voltage‑restrained), ground fault (100% stator earth), negative sequence overcurrent

Rotor: Loss of excitation, reverse power, over/undervoltage, over/underfrequency

Mechanical: Bearing overtemperature (12 RTD inputs), vibration monitoring (4 analog inputs)

Timing: IEC inverse / definite time curves; trip time ≤15 ms (instantaneous)

I/O & Interfaces

Analog Outputs: 4 × 4–20 mA, isolated

Digital Inputs: 9 opto‑isolated (dry/wet contact, ≤1 ms response)

Relay Outputs: 6 Form C (5 A / 250 VAC)

RTD Inputs: 12 × 3‑wire (100Ω Pt, 100/120Ω Ni, 10Ω Cu)

Communication: RS‑232 (front, programming), RS‑485 (Modbus RTU/DNP3.0); no Ethernet

Display & User Interface

Display: Enhanced 40‑character backlit LCD

Indicators: 10 LED status (RUN, TRIP, ALARM, FAULT, SERVICE)

Keypad: Numeric/navigation for local programming

Mechanical & Environmental

Dimensions: 177.5 mm H × 128.5 mm W × 119 mm D

Mounting: DIN rail or panel mount

Enclosure: Flame‑retardant plastic; IP50 (front), IP20 (overall)

Operating Temp: -40°C to +70°C

Storage Temp: -40°C to +85°C

Humidity: 5–95% non‑condensing

Certifications: UL, CE, CSA, IEC 60255

Metering & Diagnostics

Metering: 3‑phase current/voltage, power, energy, frequency, PF, demand (0.5% accuracy)

Diagnostics: Event log (512 events), fault recorder (128‑cycle oscillography), pre‑trip data

Thermal Modeling: RTD biasing, current unbalance biasing, cooling time constants

Core Functions

Comprehensive Generator Protection: Guards against stator/rotor electrical faults and mechanical issues (bearing overheating, vibration).

Precision Monitoring: Real‑time tracking of electrical parameters and winding/bearing temperatures via RTDs.

Low‑Voltage Compatibility: Wide‑range LO power for 24/48 VDC industrial systems.

Flexible Control: Configurable grid‑connection logic, protection curves, and fault responses.

SCADA Integration: Modbus RTU/DNP3.0 over RS‑485 for remote monitoring/control.

Enhanced Local Operation: Large LCD for clear diagnostics and on‑site programming.

Applications

Industrial Generators: Small‑to‑medium synchronous/induction generators (low‑voltage)

Power Plants: Auxiliary generators, co‑generation systems

Oil & Gas: Onshore generator sets, gas turbine units

Water Treatment: Biogas generators, backup power systems

Manufacturing: Emergency/standby generators, island‑mode operation

Usage & Maintenance

Installation: Mount on DIN rail/panel; wire CT/VT, LO control power, RTDs, and communications.

Programming: Use front keypad or connect to EnerVista 489 software via RS‑232.

Configuration: Set CT/VT ratios, protection curves, RTD types, and I/O mapping.

Maintenance: Inspect terminals annually; update firmware periodically; verify settings after system changes.