Earth-leakage protection relay ELR-6MS

DCACDIN rail

Overview
The ELR-6MS Earth Leakage Relay is a high-reliability protection device designed specifically for the mining industry, suitable for both underground and surface applications. Engineered for mobile trailing-cable equipment, it features a microcontroller-based architecture that automatically operates in two protection modes: ground-fault detection and ground resistance (ground check) detection. This advanced design minimizes nuisance tripping while ensuring enhanced safety for personnel and equipment.

Function introduction

• Ground Fault Detection: Requires the use of current sensors; the ELR-6MS is designed to operate with zero-sequence sensor ratios of 1000:1, 600:1 and 40:1 (200:5).
• Ground Check Detection: Achieved using a pilot wire (GC). The pilot wire carries monitoring current to the machine being monitored and must be properly terminated with an industry-standard Zener diode terminator (two terminals marked GC and GD). The GC terminal is connected to the pilot wire inside the mobile equipment enclosure; the GD terminal is connected to the machine frame ground. Loss of Zener voltage causes the TRIP relay to operate, detecting shorted or open ground loops and protecting against ungrounded equipment conditions.

Wiring
The product implements pilot-wire ground-check wiring; wiring diagrams are provided in the product documentation and illustrations. Proper termination of GC/GD with the Zener diode terminator is required for correct ground-check function.

Caractéristiques / spécifications techniques

• Normal voltage: 90–240 Vac/dc, 50/60 Hz. Power consumption: 5 VA (AC) or 5 W (DC).
• Ground fault: Range 10–500 mA. Delay range: instant to 10 seconds.
• Zero-sequence sensors: Ratios supported 1000:1, 600:1 and 40:1 (200:5).
• Ground check resistance: Range 10–50 Ω, ±15%. Trip delay for ground check: 150 ms, ±0.1%.
• Output contacts (3 DO): Main trip relay — DPDT, load capacity 8 A @ 250 Vac, 8 A @ 30 Vdc.
• Auxiliary ground fault relay — SPDT, load capacity 16 A @ 250 Vac, 16 A @ 30 Vdc.
• Auxiliary ground check relay — SPDT, load capacity 16 A @ 250 Vac, 16 A @ 30 Vdc.
• Dielectric: Relay contacts to chassis — 1500 Vrms for 1 minute. Control terminals to chassis — 1500 Vrms for 1 minute.
• Temperature range: Operating −40 °C to +60 °C. Storage −40 °C to +80 °C.
• Mounting and dimensions: Standard 35 mm DIN‑rail mounting. W × H × D: 108 × 110 × 66 mm.