The output dry contact can wear with time. Tx3-series Dry SPDT UL operation zones are : 0.5Amp@120VAC to 5Amp@30Vdc and have Mean Time Between Failure of 1,800 cycles per hour or a total of 50,000 operations in one life time (100days @ 500 door opens per day). A typical SPDT relay wear points is the contact between the contact or continuity between “ common” and “NO” or “NC” . After a while, in high traffic zones the resistance exceeds the input sensing of the device. From that, all that is required is to change dry-SPDT relay point for immediate corrective action. Other factors associated to dry-SPDT relay wear is high current feeds. In some cases, it’s the high inductive rush current that causes dry-SPDT relay failure. In this case, examination of the inrush current should be measured if fast relay wear has been noted.