GESTRA NRS2-50+T Steam Boiler Water Level Equipment 24Vdc The level switch NRS 2-50 / NRS 2-51 in conjunction with level electrodes NRG 2.-.. and level transmitter NRGT 26-1is used as limit switch and water level controller, for instance in steam boilers, (pressurized) hot-water installations as well as condensate and feedwater tanks. The level switch detects and indicates when the preset MIN or MAX water level is reached and in addition switches the feedwater pump on and off (NRS 2-51). The level switch is designed to be used with level electrodes NRG 21-.. and NRG 26-21 as well as the level transmitter NRGT 26-1. Please allow 2-3day delivery