Easergy P3U30 Microprocessor-Based Protection and Control Device

I. Product Positioning
A universal medium-voltage multifunctional microprocessor-based protection and control device, part of the Easergy P3 standard series. The “U” stands for Universal, and “30” indicates the high-end configuration. It covers full-scenario protection for feeders, transformers, motors, capacitors, and small generators, replacing older Sepam and MiCOM relay protection devices.

Core Hardware Specifications
1. Analog Inputs
Current: 3-phase CT (1A/5A selectable) + 1 zero-sequence current Io
Voltage: 4 VT inputs (three-phase line voltages + zero-sequence voltage)
Temperature extension: up to 12 external RTD temperature inputs (winding, oil, ambient)

2. Digital I/O
16 digital inputs (DI), adaptive to 24–230V AC/DC
8 digital outputs (DO) + 1 watchdog alarm relay

3. Power Supply
Auxiliary power: wide-range universal input of 48–230V AC/DC

4. Communication Interfaces
Front USB: local debugging, set value downloading, waveform export
Backplane RS485 standard; optional Ethernet via fiber or copper cable (supports PRP/RSTP dual-network redundancy)
Supported protocols: Modbus RTU, IEC60870-5-101/103, DNP3, IEC61850 Ed1/Ed2, SPA bus

5. Structure and Installation
Standard 30TE 19-inch rack-mountable plug-in design with removable terminal blocks. Front panel features LCD HMI with simulated primary circuit diagram, programmable function keys F1/F2, and multilingual interface

Complete ANSI Protection Functions (40+ Protection Logics)
Current-Based Protections
Phase overcurrent 50/51, directional overcurrent 67, cold load pickup CPLU, closing failure SOTF
Zero-sequence ground fault 51N/50N, directional grounding 67N, transient grounding 67NI
Negative sequence overcurrent 46 (phase loss/unbalance), undercurrent 37, locked rotor/start timeout 48/51LR, motor restart interlock 66
Breaker failure 50BF, CT open-circuit monitoring 60, capacitor unbalance 51C

Voltage/Frequency-Based Protections
Overvoltage 59, undervoltage 27, zero-sequence overvoltage 59N, capacitor overvoltage 59C; over/under frequency 81O/81U, rate of frequency change 81df/dt, synchronism check 25

Equipment-Specific Protections
Transformer: thermal overload 49T, gas/oil temperature external trip, tank earth leakage protection
Motor: locked rotor, phase loss, thermal accumulation overload
Feeder: fault location 21FL, reclosing 79, logical selective interlocking
General: low-power reverse 32P, lockout trip 86, programmable multi-stage set value groups