Kromschroder Air pressure switch DL1,5A-3 84444411

The Kromschroder DL1,5A-3 air pressure switch (SKU 84444411) is a diaphragm pressure switch designed to monitor positive, negative, or differential air and flue gas pressures. It features a glass fibre reinforced PBT plastic housing, a tempered LSR diaphragm system, and a microswitch conforming to EN 61058-1. The switch has a connection thread of Rp 1/4, screw terminals for electrical connection, and an adjustment handwheel. It weighs 300 g, with cover screw and strain relief facility torque set at 65 Ncm. The device complies with safety class II per VDE 0106-1 and standards EN 13611 and EN 1854.

When selecting a replacement pressure switch of this type, ensure the connection thread (e.g., Rp 1/4) matches the existing piping, and verify the electrical connection type (screw terminals) and voltage/current ratings of the microswitch. The adjustment range and pressure type (positive, negative, or differential) must be compatible with the system's requirements. Mounting orientation and ambient temperature limits should be checked against the installation site. Always compare the physical dimensions and housing design to ensure proper fit and access to the adjustment handwheel.

Common failure modes for diaphragm pressure switches include diaphragm rupture or leakage, leading to loss of pressure sensing and incorrect switching. Symptoms may include the burner or boiler failing to start, frequent cycling, or safety lockouts due to false pressure readings. Check for visible damage to the diaphragm, corrosion on terminals, or loose connections. Verify the switch operation by measuring continuity across the microswitch while applying controlled pressure.