The Gestra NRS 1-51 is a high-level alarm level switch used in steam boilers and pressurized hot-water systems to prevent overfilling by triggering alarms or shutting off feedwater supply when the water level exceeds a preset maximum.

Technical Specifications

• Model: NRS 1-51
• Function: High-level alarm switch
• Measurement Principle: Conductivity-based level detection
• Compatible Electrodes:
  • NRG 16-51
  • NRG 17-51
  • NRG 19-51
  • NRG 111-51
• Power Supply: 24 V DC or 230 V AC (depending on version)
• Output: Relay contact for alarm or control signal
• Mounting: DIN rail installation
• Protection Class: IP 40 (housing), IP 20 (terminals)
• Ambient Temperature: 0–55°C