Kromschroder Air pressure switch DL5A-31 84444470

The Kromschroder DL5A-31 is a diaphragm pressure switch designed to regulate positive, negative, or differential air and flue gas pressures. It has an adjusting range of 0.4 to 5 mbar and features a tempered LSR diaphragm system. The housing is made of glass fibre reinforced PBT plastic with low gas release, and the electrical connection is via screw terminals. The switch operates with a microswitch to EN 61058-1 and meets safety class II to VDE 0106-1. It weighs 300 g and has a connection thread of Rp 1/4.

When selecting a replacement pressure switch of this type, verify the pressure range, connection thread size, and electrical ratings match the original. Ensure the medium (air or flue gas) is compatible and that the switch is suitable for the system's pressure type (positive, negative, or differential). Mounting may involve threaded or tube connections; check the existing installation for the correct form. The cover screw and strain relief torque should be set to the specified values during installation.

Common failures include diaphragm rupture or leakage, leading to loss of pressure sensing and incorrect burner operation. The microswitch may fail due to electrical arcing or mechanical wear, causing the burner to shut down or fail to start. Symptoms may include erratic pressure readings, failure to maintain setpoint, or the burner not responding to pressure changes. Check for physical damage, contamination, or loose electrical connections.