Two things cause switch failure:
1) Excessive Current: Switch protected from excessive current by Quick Blow Fuse. Maximum reed switch rating is .5 amp. = 500 mA switching. If current exceeds .5 amp. fuse will blow. In Fail Safe condition, switch must be replaced.
2) High Voltage: SIDActor threshold 60 AC/DC volts. If voltage exceeds 60 volts, SIDActor will clamp down, channeling any voltage above 60 directly to ground but will not cause switch device to fail or misoperate and will continue to work.
Fails Safe With Excessive Current Micro-Weld Switch Protection Channels Voltage Above 60 V To Ground Available In Recessed and Surface Styles Plus Heat Shrink For In-Line Installations