Kromschroder Gas pressure switch DG150H-3 84447640

The Kromschroder DG150H-3 is a diaphragm pressure switch designed to monitor gas or air pressure, with an adjusting range of 30–150 mbar. It operates mechanically and features a NBR diaphragm, with a housing made of glass fibre reinforced PBT plastic and a lower housing section of AlSi 12. The switch is silicone-free, has low gas release, and is rated IP54. It is suitable for media such as natural gas, town gas, LPG (gaseous), flue gas, biogas (max. 0.1% by vol. H2S), and air. The device has a maximum medium and ambient temperature range of -15 to 60 °C, a storage temperature of -20 to 40 °C, and weighs 0.321 kg.

When selecting a pressure switch of this type, verify the required pressure range, connection thread (e.g., M16 x 1.5), and electrical connection specifications. Ensure the switch is compatible with the medium and ambient temperature conditions. Mounting typically involves connecting the pressure line to the switch and wiring the electrical terminals, with the line entrance accommodating cable diameters of 4 to 10 mm. The switch may be installed in any orientation, but the diaphragm must be positioned correctly to sense pressure changes.

Common failure modes for diaphragm pressure switches include diaphragm rupture or leakage, which can cause the switch to fail to actuate or to actuate at incorrect pressures. Symptoms may include burner lockout, failure to start, or erratic pressure control. Check for visible damage to the diaphragm, verify the setpoint against a manometer, and inspect for gas leaks around the switch.