Gestra NRG17-51 Level Probe 1500mm
The level electrodes NRG 17-51 are used in conjunction with level switch NRS 1-51 as high water level alarms for steam boiler plants and (pressurized) hot water installations. A high level alarm prevents the water level from exceeding the preset max. water level (HW) and for this purpose switches off e. g. the feedwater supply.

When the level exceeds the max. water level, the level electrode enters the liquid and an alarm is triggered in the level switch NRS 1-51. The switchpoint “High level (HW) exceeded” is dictated by the length of the electrode rod.

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 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 protective tube mounted on site ensures correct functioning. One level electrode NRG 1...-51 can be installed together with one Gestra water level limiting electrode in a single protection tube or external 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 to be internal. In this case the rinsing processes do not have to be monitored.