Gestra Water Level Limiter NRG 16-50 NRG 17-50, NRG 19-50 NRG 111-50

Description:

The level electrodes NRG 1...-50 are used in conjunction with level switch NRS 1-50 as water level limiters for steam boiler plants and (pressurised) hot water installations. Water level limiters switch off the heating when the water level falls below the set minimum level (low water).

Function

When the water level falls below the low level, the level electrode is exposed and a low level alarm is triggered in the level switch NRS 1-50. This switchpoint “Low water level (LW)” is determined by the length of the electrode tip. The electrode operation is based on the conductive measuring principle using the electrical conductivity of the water for signalling water level. The self-monitoring function ensures that an alarm will also be triggered if the electrode insulation is contaminated or has developed a leak and/or if there is a malfunction in the electrical connection. The level electrode is installed inside steam boilers, vessels or inlet lines of hot-water systems. The protection tube provided on site ensures the function. One level electrode NRS 1...-50 can be installed together with one GESTRA level electrode, one level switch or transmitter for water level control and high level alarm in one single protection tube or level pot. If the level electrode is installed in a level pot outside the boiler, make sure that the connecting lines are rinsed regularly. In addition, the logic unit SRL is required to monitor the purging times and the purging sequence. If the connecting lines for steam ≥ 40 mm and water ≥ 100 mm the installation is considered as “inside”. In this case the purging process does not have to be monitored.

Service pressure

• NRG 16-50, PN 40, 32 bar at 238 °C
• NRG 17-50, PN 63, 60 bar at 275 °C
• NRG 19-50, PN 160, 100 bar at 311 °C
• NRG 111-50, PN 320, 183 bar at 357 °C

Connection

• Screwed G ¾ A, ISO 228 (NRG 16-50, NRG 17-50, NRG 19-50)
• Screwed G 1 A, ISO 228 (NRG 111-50)

Materials

• Sheath: 1.4301 X5 CrNi18-10 Screw-in
• body: 1.4571 X6 CrNiMoTi 17-12 -2 (NRG 16-50, NRG 17-50, NRG 19-50)
• Screw-in body: 1.4529, X1NiCrMoCuN25-20-7 (NRG 111-50)
• Measuring electrode: 1.4571 X6 CrNiMoTi 17-12 -2 (NRG 16-50, NRG 17-50, NRG 19-50)
• Measuring electrode: 1.4122, X39CrMo17-1 (NRG 111-50)
• Electrode tip: 1.4401 X5 CrNiMo 17-12-2
• Electrode insulation: Gylon® (NRG 16-50, NRG 17-50, NRG 19-50)
• Electrode insulation: special ceramic (NRG 111-50)
• NRG 1...-50: Four-pole connector: polyamid (PA)
• NRG 1...-50F: Terminal box 3.2161 G AlSi8Cu3

Lengths supplied

• 500 mm,
• 1000 mm,
• 1500 mm,
• 2000 mm,
• 2500 mm,
• 3000 mm

Gestra Water Level Limiter NRG 16-50 NRG 17-50, NRG 19-50 NRG 111-50

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