Had a sensor fail at a condo job in Tampa last Tuesday

I was finishing up a panel swap at a 12 unit condo building near the harbor. Everything was going smooth until I tested zone 3 and got nothing. Turns out the contact was mounted on an aluminum door frame with no spacer and corrosion ate through the wire. Took me 45 minutes to trace it back. Has anyone else run into weird sensor failures on metal frames?

3 comments

3 Comments

morgan_bailey933d ago

Spraying a little dielectric grease on the contact points before mounting fixed a similar issue for me on a saltwater condo job. Also switched to stainless steel brackets instead of the standard aluminum ones, never had a callback since.

the_simon2d ago

The 2016 IBC Table 2504.2 actually lists a minimum 1/16 inch separation requirement for dissimilar metals in saltwater zones. That grease is just buying time until the salt spray works its way in anyway. I've seen stainless brackets fail within 18 months on Florida beachfront condos because nobody accounted for the chloride pitting. The real fix is using nylon or composite washers between the metals and upgrading to 316L stainless instead of the standard 304. Aluminum is actually fine if you paint the mounting surface with a marine grade epoxy first. The corrosion isn't from the bracket itself, its from the micro-vibrations wearing through the coating over time.

shanem373d agoTop Commenter

Wait until those stainless brackets corrode from galvanic reaction with the mounting surface, then you'll be chasing a different kind of callback. Dielectric grease is a bandaid, not a fix for poor drainage or wrong materials.