Overview
The AM2SE series is a compact and cost-effective numerical protection relay designed by Acrel for power systems up to 20kV.
Integrating protection and control functions, it features mature protection algorithms, an industrial-grade hardware platform, and flexible I/O configuration. The series offers both vertical (AM2SE-V) and horizontal (AM2SE-H) mounting versions with identical functionality. With 4 current inputs, 3 voltage inputs, 8 digital inputs, 5 relay outputs, and 1 RS485 communication port supporting Modbus-RTU and IEC60870-5-103,
the AM2SE series provides reliable protection for feeders, bus couplers, distribution transformers, and other primary equipment in distribution networks. Its compact size and two mounting orientations make it ideal for new installations or retrofitting existing switchgear.
Highlight
Comprehensive Protection
- 3-stage O/C with UV & 2nd harmonic lock
- Zero-seq, negative seq, recloser, UFLS
- Non-electric & voltage alarms
Flexible DI Customization
- 8 DI freely mapped to status/non-electric
- Supports breaker positions, remote, etc.
- Simple code-based configuration
Industrial-grade Reliability
- Level IV EMC (EFT, ESD, Surge)
- Wide temp: -10°C to +55°C
- High insulation: >100MΩ
Compact & Dual-Orientation Design
- Vertical (150×68mm) or horizontal (68×150mm)
- Panel flush mounting, easy installation
- Space-saving for narrow cabinets
Function
| Parameter | Value |
| Auxiliary Power | AC/DC 220V, 110V; DC 48V, 24V (±20%) |
| Power Consumption | ≤10 W (DC) |
| Rated Voltage | AC 100V or 100/√3V |
| Voltage Measurement Range | 1～120V |
| Voltage Accuracy | ±0.5% |
| Rated Current | AC 5A or 1A |
| Current Measurement Range | 0.04In～15In |
| Current Accuracy | ±0.5% |
| Frequency | 50/60 Hz (±0.1 Hz) |
| Digital Inputs | 8 channels, wet contact (voltage specified in order) |
| Digital Outputs | 5 relay outputs (NO) |
| Communication | 1 × RS485, Modbus-RTU / IEC60870-5-103 (selectable) |
| Fault Records | >200 events |
| 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 | IP30 (front panel) |
| Dimensions (H×W×D) | AM2SE-V: 150 × 68 × 100 mm (cut-out 150×68 mm) AM2SE-H: 68 × 150 × 100 mm (cut-out 68×150 mm) |
| Mounting | Panel flush mounting |
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Specification
| Parameter | Value |
| Auxiliary Power | AC/DC 220V, 110V; DC 48V, 24V (±20%) |
| Power Consumption | ≤10 W (DC) |
| Rated Voltage | AC 100V or 100/√3V |
| Voltage Measurement Range | 1～120V |
| Voltage Accuracy | ±0.5% |
| Rated Current (AM3SE-I) | AC 5A or 1A |
| Current Measurement Range | 0.04In～15In |
| Current Accuracy | ±0.5% |
| Frequency | 50/60 Hz (±0.1 Hz) |
| Digital Inputs | 11 channels, wet contact (voltage specified in order) |
| Digital Outputs | 5 relay outputs (NO) |
| Communication | 1 × RS485, Modbus-RTU / IEC60870-5-103 (selectable) |
| Event Records | >200 events |
| 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 | IP30 (front panel) |
| Dimensions (H×W×D) | 122 × 152 × 100 mm |
| Cut–out | 152 × 122 mm |
| Mounting | Panel flush mounting |
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FAQ
They are functionally identical. The only difference is the mounting orientation: AM2SE-V is vertical (150×68 mm cut-out), AM2SE-H is horizontal (68×150 mm cut-out). Choose based on your panel layout.
In the “DI Config” menu, enter the corresponding code from the tele-signal mapping table (Appendix 2) to map each DI to a status, non-electric signal, strap, or signal. This allows flexible adaptation to your switchgear wiring.
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. Via the RS485 port, using Modbus or IEC103 protocols, you can remotely modify settings, switch setting groups, and retrieve event records.
Four independent setting groups (00, 01, 02, 03) can be stored and switched remotely or locally.
The AM2SE provides basic overcurrent and negative-sequence protection, but for comprehensive motor protection (thermal overload, stall, start-up supervision) we recommend the AM5SE-M series.
Yes, the AM2SE records fault data when a protection trip occurs. It stores more than 200 event records with time stamps and fault values.
The cut-out dimensions are 150×68 mm for vertical and 68×150 mm for horizontal. These compact sizes simplify retrofitting into existing panels with limited space.
Summary
The AM2SE series offers a compact, cost-effective, and highly reliable protection solution for 20kV and below distribution systems. With its comprehensive protection functions, flexible DI customization, industrial-grade EMC, and dual-orientation design, it meets the needs of diverse applications—from feeders and transformers to retrofitting projects. Whether for new installations or upgrading existing switchgear, the AM2SE series delivers essential protection with simplicity and value.
