Gestra NRG19-51 Level Probe 1500mm
The level electrodes NRG 19-51 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 maximum water level (HW) and switches off (for example) the feedwater supply when it does.

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

The electrode operates 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, develops a leak or if there is a malfunction in the electrical connection.

When installed inside steam boilers, vessels, or inlet lines of hot-water systems protective tube mounted on-site ensures the correct functioning of the level-electrode. One level electrode NRG 1...-51 can be installed alongside a Gestra water level limiting electrode in a single protection tube or within an external level pot.

If the level electrode installation is within a level pot outside the boiler, ensure that the connecting lines are cleaned and rinsed regularly. In addition, the logic unit SRL is a requirement to monitor the purging times and the purging sequence.

When connecting lines for steam are ≥ 40mm and water ≥ 100mm the installation is considered internal. In this case, the rinsing process does not require monitoring.