Overview
AM5SE series is a comprehensive protection and monitoring IED (Intelligent Electronic Device) designed by Acrel for power systems up to 35kV.
Integrating protection, control, measurement, communication, and fault recording, it features a high-performance hardware platform with a 168MHz processor and 48-point/cycle sampling.
The modular design supports a wide range of applications—feeders, transformers, motors, capacitors, bus couplers, PTs, and more—through a single hardware unit with downloadable logic profiles.
With abundant I/O, dual Ethernet and RS485 ports, USB maintenance port, and Level IV EMC immunity, the AM5SE series delivers reliable, flexible, and future-proof protection for medium-voltage distribution networks
Highlight
High-Performance Platform
- 168MHz CPU, 16-bit ADC, 48 pts/cycle
- 512KB Flash, 4MB external NorFlash
- Real-time parallel computing
Rich I/O & Communication
- Up to 14 AI, 20 DI, 10 DO
- Dual RS485 + Dual Ethernet
- USB, RS232, IRIG-B, 2×4-20mA (optional)
Comprehensive Protection & Recording
- 15+ logic libraries (feeder, transformer, motor, etc.)
- 16 fault records, 12 triggers each
- Pre-fault 8 cycles, post-fault 4 cycles
Industrial-grade Reliability
- Level IV EMC (EFT, ESD, Surge)
- Operating temp: -10°C to +55°C
- Adaptive trip circuit (0.25-5A)
Focus Areas
| Series | Typical Application | Protection Highlight |
| AM5SE-F | Feeders/Incoming Lines | Three-stage O/C (dir./UV), recloser, UFLS, zero-sequence |
| AM5SE-T | Power Transformer (>2000kVA) | Three-stage O/C+CTS, negative/zero seq., gas/temp./pressure non-elec. |
| AM5SE-M/MD | HV Motor | Start/run O/C, stall, thermal overload, under/over volt, phase seq./loss |
| AM5SE-C | Capacitor Bank | Two-stage O/C, under/over volt, unbalance volt/current |
| AM5SE-B | ATS (Bus/Incoming) | Bus/Incoming/Adaptive/Cut-off ATS |
| AM5SE-UB | PT Paralleling/Splitting | Auto/remote PT parallel/split, two-stage PT break alarm, resonance elimination |
| AM5SE-IS | Anti-Islanding (DG) | Reverse power, low power, power recovery, voltage recovery close, sync-check |
Function
| Model | Protection Functions |
| AM5SE–F | 3-stage O/C (directional/UV lock), recloser, UFLS, I01/I02 O/C, post-acceleration, check sync |
| AM5SE–T | 3-stage O/C + CTS, negative/zero seq O/C, gas/temp/pressure non-electric, overload |
| AM5SE–M | Start/run O/C, thermal overload, stall, under/over volt, unbalance, phase seq, phase loss |
| AM5SE–MD | Motor differential (87M), plus all AM5SE-M functions |
| AM5SE–C | 2-stage O/C, under/over volt, unbalance volt/current |
| AM5SE–B | Bus/incoming ATS, adaptive ATS, cut-off ATS |
| AM5SE–UB | PT auto/remote paralleling/splitting, PT break alarm, resonance elimination |
| AM5SE–IS | 2-stage reverse power, ROCOF, under/low power, power recovery, check sync, voltage recovery close |
Model Selection
| Model | AC Inputs | DI | DO | Ctrl Circuit | Key Feature |
| AM5SE-F | 8I + 6U | 20 | 10 | √ | Recloser, UFLS |
| AM5SE-T | 8I + 4U | 20 | 10 | √ | Power Transformer Non-elec. |
| AM5SE-M | 8I + 4U | 20 | 10 | √ | Motor Protection |
| AM5SE-MD | 9I + 4U | 20 | 10 | √ | Motor Differential |
| AM5SE-D2/D3 | 9I + 4U (D2) / 9I+4U (D3) | 20 | 10 | – | 2/3-Winding Transformer Diff. |
| AM5SE-B | 8I + 6U | 20 | 10 | √ | ATS |
| AM5SE-UB | 0I + 8U | 20 | 10 | – | PT Paralleling & Resonance Elim. |
| AM5SE-IS | 6I + 8U | 20 | 10 | √ | Anti-Islanding, Reverse Power |
| AM5SE-FD | 8I + 6U | 12 | 64 | – | Non-elec. Re-transmission |
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Step 1: Identify Protection Object
Feeder: -F, Transformer: -T, Motor: -M/-MD, Capacitor: -C, ATS: -B, PT cabinet: -UB, PV/ESS: -IS.
Step 2: Confirm Voltage/Current Ratings
Standard: AC 100V/5A or 1A; -IS/-FE/-FA support direct AC 380V/220V connection.
Step 3: Select Communication & Options
Standard: dual 485 + dual Eth; Optional: 4-20mA, IRIG-B.
Specification
| Parameter | Value |
| Auxiliary Power | AC/DC 220V or 110V (±20%) |
| Power Consumption | ≤15 VA |
| Rated Voltage | AC 100V or 100/√3V (except -IS/-FE/-FA: AC 380V/220V) |
| Voltage Range | 0.1～120V (except -IS/-FE/-FA: up to 456V) |
| Rated Current | AC 5A or 1A |
| Current Range | 0.04In～20In (protection), 0.04In～1.5In (measurement) |
| Frequency | 50/60 Hz (±0.1 Hz) |
| Digital Inputs | 20 channels (AC/DC 220V or 110V) |
| Digital Outputs | 10 relay outputs (DO9, DO10 NC, others NO) |
| Analog Outputs | 2 × 4-20 mA (optional) |
| Communication | 2 × RS485 (Modbus-RTU, IEC103), 2 × Ethernet (TCP Modbus, TCP IEC103) |
| Time Synchronization | IRIG-B (RS485) |
| Maintenance Ports | USB (front), RS232 |
| Fault Records | 16 records, 12 triggers each, 46s total |
| Operating Temperature | -10°C ～ +55°C |
| Storage Temperature | -25°C ～ +70°C |
| Relative Humidity | 5%～95% (non-condensing) |
| Altitude | ≤2500 m |
| Insulation Resistance | >100 MΩ @500Vdc |
| Dielectric Strength | 2 kV between circuits and earth |
| EMC Immunity | Level IV for EFT, ESD, Surge (per GB/T 14598.26) |
| Protection Degree | IP20 (front panel) |
| Dimensions (H×W×D) | 245.5 × 158 × 100 mm (cut-out 245.5×158 mm) |
| Mounting | Panel flush mounting |
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FAQ
AM5SE is a full-featured IED with advanced functions like fault recording, dual Ethernet, USB, and extensive I/O (20DI/10DO). AM3SE is a cost-optimized relay with basic protection, 11DI/5DO, and single RS485. Choose AM5SE for complex substations requiring high-end features and AM3SE for simple feeder/transformer protection.
The AM5SE uses a universal hardware platform. Simply select the “Protection Object Type” in the device parameters—the corresponding logic library is automatically activated. No hardware change or reprogramming needed.
Yes. Insert a USB flash drive into the front USB port, navigate to Record → Fault Record → Export, and transfer the COMTRADE files. Use the Acrel Disturbance Analysis Tool to view waveforms and harmonics.
Yes. Via the RS485 or Ethernet ports, using Modbus or IEC103 protocols, you can remotely modify settings, switch setting groups, and retrieve event records.
Operating temperature is -10°C to +55°C. For outdoor installations, use a weatherproof enclosure with proper ventilation. The device meets Level IV EMC for harsh environments.
Yes, the AM5SE includes an internal anti-pumping function. No external module is needed. You can enable/disable it via settings.
Four independent setting groups (00, 01, 02, 03) can be stored and switched remotely or locally.
Yes, the AM5SE-MD model is specifically designed for motor differential protection (87M) with ratio restraint and 2nd harmonic blocking.
The Ethernet ports support TCP Modbus-RTU and TCP IEC60870-5-103, selectable via menu.
Yes, all AM5SE models share the same cut-out size: 245.5×158 mm. This simplifies panel design and future upgrades.
Summary
AM5SE series represents a new generation of protection IEDs that combine powerful hardware, versatile software, and robust communication into a single platform. With its universal hardware design, one device can cover feeder, transformer, motor, capacitor, ATS, and PT protection—simplifying engineering, reducing spares inventory, and accelerating deployment. Advanced features like 48-point sampling, 16 fault records, dual Ethernet, and Level IV EMC ensure precise operation and long-term reliability. Whether for greenfield substations or retrofitting existing switchgear, the AM5SE series delivers a future-ready solution for medium-voltage distribution automation.
