DEESYS DER-P03 Earth Leakage Relay

Overview

The DEESYS DER-P03 is an earth leakage protection relay manufactured by Deesys, Korea. The DEESYS DER-P03 works with an external zero-sequence current transformer to detect residual leakage current in AC power circuits. The DEESYS DER-P03 provides adjustable leakage current thresholds and trip/alarm relay output for electrical shock protection, insulation fault monitoring and fire prevention in industrial distribution panels, generator systems and marine electrical installations. It is a widely stocked protection spare for low-voltage electrical safety circuits.

Features

The DEESYS DER-P03 supports multiple selectable leakage current settings: 0.03A, 0.05A, 0.07A and 0.1A. The DEESYS DER-P03 includes a built-in test button for periodic function verification and reset function after fault tripping. The DEESYS DER-P03 operates on 240 V AC auxiliary supply, 50/60 Hz, and accepts residual current signal from a matched CT. It provides isolated relay contacts for tripping circuit breakers or sending alarm signals to PLC and SCADA systems. The compact DIN rail mounting form factor of the DEESYS DER-P03 fits standard cabinet installation and enables direct replacement for existing DER-P03 units.

Specs

Device Type: Earth Leakage Relay Model: DEESYS DER-P03 Brand: Deesys (Korea) Auxiliary Supply: 240 V AC Frequency: 50 / 60 Hz Leakage Current Settings: 0.03 A, 0.05 A, 0.07 A, 0.1 A Detection Ratio: 53%–75% active current pickup Interface: External zero-sequence CT input Output: Relay trip / alarm contacts Mounting: DIN rail mount Operating Temperature: -20°C ~ +60°C Protection Grade: IP20 inside control cabinet

Principle

The DEESYS DER-P03 monitors the vector sum of phase and neutral currents via the zero-sequence CT. When insulation degradation occurs, leakage current flows to earth and creates an unbalanced residual current signal. Once the residual current exceeds the selected threshold, the DEESYS DER-P03 activates the internal relay output to trigger breaker trip or alarm notification. The test circuit simulates leakage current to confirm the relay and CT loop are functional.

Applications

The DEESYS DER-P03 is used for earth fault protection in low-voltage power distribution, generator control panels, marine switchboards and industrial machine electrical systems. It reduces risks of electric shock and cable insulation fire caused by earth leakage. The DEESYS DER-P03 is stocked as spare part for emergency replacement and scheduled electrical safety maintenance. It also supports insulation monitoring loop renovation and protection coordination projects.