Kromschroder Air pressure switch DL5AT-2N 84444970

The Kromschroder DL5AT-2N air pressure switch (SKU 84444970) is a diaphragm-based pressure switch designed for use with air or flue gas. It operates over a pressure range of 0.5–5 mbar and can sense positive, negative, or differential pressure. The switch features a glass fibre reinforced PBT plastic housing with an NPT 1/4 connection thread and a 1/2 NPT conduit thread. It includes a blue pilot lamp for 110/120 V AC, a micro switch conforming to EN 61058-1, and a tempered LSR diaphragm system. The device weighs 54 g, has a protection class of IP54, and is certified to CE-0085AP0466, complying with EN 13611:2015+AC:2016 and EN 1854:2010.

When selecting a replacement pressure switch of this type, verify the pressure range, connection thread size, and electrical ratings (voltage and current) match the original. Ensure the switch is suitable for the medium (air or flue gas) and the required pressure type (positive, negative, or differential). Mounting may involve threaded connections or conduit fittings; check the physical dimensions and conduit thread (e.g., 1/2 NPT) to fit the existing installation. Also confirm the protection class (e.g., IP54) meets the environmental requirements.

Common failure modes for pressure switches of this kind include diaphragm rupture or leakage, leading to loss of pressure sensing or false triggering. Symptoms may include the burner failing to start, intermittent shutdowns, or the switch not responding to pressure changes. Check for physical damage, contamination, or blockage in the pressure ports, and verify the electrical continuity of the micro switch. If the switch is stuck open or closed, it may prevent proper operation of the burner control system.