Kromschroder Air pressure switch DL3A-3T 84444404

The Kromschroder DL3A-3T is a diaphragm pressure switch designed for air or flue gas pressure monitoring in boilers and ventilation systems. It has an adjustable pressure range of 0.2–3 mbar and features a Rp 1/4 threaded connection. The switch operates on a 220–240 V supply and includes a blue pilot lamp. Its housing is made of glass fibre reinforced PBT plastic, and it uses a tempered LSR diaphragm system. The device weighs 250 g and has a designed lifetime of 10 years, complying with EN 13611 and EN 1854 standards.

When selecting a pressure switch of this type, verify the required pressure range, connection thread size, and electrical supply voltage. Ensure the medium (air or flue gas) is compatible with the switch materials. Mounting typically involves connecting the pressure line to the threaded port and securing the electrical connections via screw terminals. The switch should be installed in a location accessible for adjustment and maintenance, with proper strain relief for cables.

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 physical damage, contamination, and verify the switch operation by applying known pressures.