Length of Sensor Electrode Setting for Extra Low Water Level on Steam Boiler
There are various brands for low water sensors, I took the example of the brand Gestra NRG type 16-4.
The NRG 16-4 Level Electrode is specifically designed to detect and mark levels in liquids with minimum electrical conductivity. Depending on the type of level switch will be used to detect the highest level or the lowest level of a liquid.
The NRG 16-4 level electrode can be used in conjunction with NRS 1-1, 1-2, 1-3 and 1-5 level switches as part of a water level control, high level alarm or level limited system on a steam boiler.
To apply a limited level system, the signal is received after the tip of the electrode is joined or exposed to the liquid. The electrode bar is simply cut according to the level of the desired level according to the boiler design.
Following are the steps to determine the stick electrode length:
1. Determine the minimum height of water by referring to the sign glass. The minimum height for sign glass is taken 10% and added 5% for expansion so that the minimum level of water is 15% of the indicator glass.
2. After that, install a long stick as a tool that is tied parallel to the sign glass and prepare a hose that has been filled with water.
3. Then measure the maximum height of the stick using a hose filled with water by increasing the height of the flange where the sensor and stick is placed which has been tied to the sign glass, then marked. From the mark on the auxiliary stick until the glass level sign 15%, that’s the height of the extra low water level sensor electrode stick in the shell boiler.
4. Cut the stick in accordance with the length that has been obtained by the way that has been done before.
5. When finished, stay installed on the flange that has been prepared.