Twice this week, our AzLM pair on the west lead went to fault after a 15-minute downpour, causing a 6-minute service hold while we performed a midnight reset and verification. For those maintaining similar setups, what preventive checks or connector sealing (IP67 glands, desiccant) have improved reliability and cut callbacks so we keep the timetable tight?
But we killed our AzLM storm-faults by replacing the field-assembled M12s at the heads with pre‑molded IP68 pigtails — those screw backshells were wicking after a “downpour” — and haven’t had a reset since. If you’re stuck with the existing plugs, re‑torque and renew the O‑rings; are your head leads still field-built?
I’d start with a pressure‑equalizing vent on the trackside JB and real drip loops below it; the pressure drop after a ‘15‑minute downpour’ pulls water past otherwise IP67 glands and isn’t worth a 6‑minute hold at midnight. We also replace the open spring terminals with sealed gel blocks and IR‑test head‑to‑shield after storms — anything under about 100 MΩ gets reworked. If you vent, skip desiccant, and ground the head cable shield at one end only per Siemens AzLM guidance: https://support.industry.siemens.com.
What stopped our AzLM storm trips was adding a low-capacitance surge protector on the head pair in the trackside JB, bonded to a clean earth bar and keeping the leads <100 mm (e.g., https://www.dehn-international.com/en/products/dehnrail); after that, even near strikes didn’t throw a “fault.” Just watch the capacitance/leakage spec and re-verify sensor balance after install, because the wrong SPD will skew it. Do you already have protection at the JB or only back at the bungalow?