Kromschroder Gas pressure switch DG50U-3T 84447355

The Kromschroder DG50U-3T is a diaphragm pressure switch designed to monitor pressure fluctuations in gas or air environments, responding to rising positive pressure (gas/air), negative pressure (air), or differential pressure (air-air). It has an adjusting range of 2.5–50 mbar and is suitable for natural gas, town gas, LPG (gaseous), flue gas, biogas (max. 0.1%-by-vol. H2S), and air. The switch features a glass fibre reinforced PBT plastic housing with low gas release, a silicone-free NBR diaphragm, and a lower housing section made of AlSi 12. It includes a blue pilot lamp for 220/240 V AC, screw terminals, and an M16 x 1.5 line entrance. The device meets safety class 1 and complies with standards EN 13611:2015+AC:2016 and EN 1854:2010, with notified body 85.

When selecting a replacement pressure switch of this type, verify the pressure range, gas or air compatibility, and electrical connection (voltage and terminal type). Check the line entrance thread size and clamping range to match the existing conduit or cable. Ensure the switch's switching function (rising or falling pressure) and any auxiliary features like a pilot lamp align with the application. Mounting is typically via a threaded connection or bracket; confirm the physical dimensions and enclosure rating (e.g., IP54) suit the installation environment.

Common failures include diaphragm rupture or leakage, leading to loss of pressure sensing and incorrect switching. Electrical contact issues may cause intermittent operation or failure to trigger. Symptoms on equipment include burner lockouts, erratic pressure readings, or failure to start. Check for gas leaks, inspect the diaphragm for damage, and verify electrical continuity and setpoint adjustment.