General
Acrel ALP220-EF Earth Fault Overcurrent Relay is designed for low-voltage applications (up to 380 V) where it is necessary to monitor the system’s ground current and provide protection when the ground current exceeds the permissible limit. This relay features an LCD display, Modbus-RTU communication capability, system current measurement, three-phase current overcurrent protection, ground current overcurrent protection, residual current measurement, residual current overcurrent protection, fault logging, and event logging functions.
Panel Display

Wiring


Technical Parameters
| Technical parameter | Qualification | ||
| Accessory power supply | Voltage range | AC/DC 85~265V | |
| Power dissipation | |||
| Import | Current specifications | ABCN (4-channel): 1A/5A | 10%Ie~1000%Ie ±2% |
| Residual currentspecification | 30mA-1000mA | ±2% | |
| Frequency | 45Hz-65Hz | ±0.2Hz | |
| Output | Output method | Dual-channel single-pole double-throw switch | |
| Output capacity | Resistive load; AC 250 V 5 A / DC 30 V 5 A | ||
| Installation andUsage Environment | Workplace Scenario | No direct exposure to rain or snow; no corrosive gases; no severe vibration | |
| Relative humidity | ≤95% RH, no condensation | ||
| Working temperature | -20℃~+70℃ | ||
| Storage temperature | -40℃~+70℃ | ||
| Height | ≤2000m | ||
| Way to install | Embedded installation: 88×88 (mm) | ||
| Levels of protection | Panel: IP54; Terminals: IP20 | ||
| Security classification | EMC | Level III | |
Functional Configuration
| Function | Standard configuration | Optional | |
| Measurement Function | Three-phase alternating current | √ | |
| Neutral conductor current | √ | ||
| Residual current | √ | ||
| Defencive function | Inverse-time overcurrent protection | √ | |
| Inverse Time Grounding | √ | ||
| Three-stage time-delayedovercurrent protection | √ | ||
| Three-stage time-delayedground fault protection | √ | ||
| Current imbalance | √ | ||
| Leakage current | √ | ||
| Communication Function | Modbus-RTU | √ | |
| Digital output function | 2 Single-pole double-throw switch | √ | |
| Record Function | 20 Single fault record | √ | |
| 20 Event Record | √ | ||
| Display Function | Liquid-crystal display | √ | |
| Setpoint Setting Function | Operation Panel Modification | √ | |
| Communication Amendment | √ | ||
Dimension


