The Siemens 7UG0818-1CD20 is a high-performance earth leakage relay from the reliable 7UG0 series, designed to protect electrical systems from fire hazards and other risks associated with earth leakage currents. This unit is part of a comprehensive monitoring relay range that includes line, voltage, current, and earth fault monitoring solutions. As an earth leakage relay, it works in conjunction with a core balance current transformer (CBCT) to detect leakage currents and trigger a trip response when preset thresholds are exceeded.
Key Technical Specifications
| Specification | Detail |
|---|---|
| Product Type | Earth Leakage Relay |
| Supply Voltage | 230V AC ±15% |
| Protection Class | IP20 |
| Model Number | 7UG0818-1CD20 |
| Siemens ID | A5E38606195A |
| Measuring Range | 10mA – 30A |
| Setting Range | 10mA – 30A |
| Trip Time Delay | 0 – 99.9 seconds (settable) |
| Response Time | <30ms for ≥5x set value; <50ms for ≥1x set value |
| Accuracy | ±5% of setting + 100ms |
| Power Consumption | Max 3VA |
| Operating Temperature | 0 to 50°C |
| Storage Temperature | -20 to +70°C |
Product Features
Precise Earth Leakage Protection
The 7UG0818-1CD20 provides comprehensive earth leakage monitoring with a wide measuring range from 10mA to 30A, making it suitable for various applications from sensitive equipment protection to general industrial use. The settable trip time delay (0–99.9 seconds) allows for fine-tuning to prevent nuisance tripping while maintaining safety.
Fast Response Times
With response times of under 30ms for faults at or above five times the set value, this relay ensures rapid detection and isolation of earth leakage faults, minimizing potential damage and safety risks.
Two-Stage Protection
The relay features two potential-free programmable contacts that can be configured for alarm and trip settings, providing flexible protection strategies and allowing for warning before a full trip occurs.
Simple Installation
The device is designed for DIN-rail mounting with a compact footprint and IP20 protection rating, making it suitable for installation in distribution boards and control panels. The unit connects to an external CBCT (core balance current transformer) that senses the leakage current in the protected circuit.
Applications
The Siemens 7UG0818-1CD20 earth leakage relay is ideal for:
- Industrial installations requiring protection against earth leakage faults
- Mining operations where earth leakage protection is mandatory by regulation
- Fire prevention systems protecting against electrical fire hazards
- Panel boards and switchgear requiring reliable earth fault monitoring
- Cement plants and heavy industry with demanding electrical environment
