Hazer wrote:They burn out closed only when over-loaded, not due to over-cycling. I have never seen one in 15 years that died closed because they exceeded expected life cycles.
The main reason is that every time it closes during normal operation, it sparks (regardless of current). They slowly build up carbonization. The contacts get so dirty, they finally no longer conduct.
I can agree with Hazer
happens to the relays in my cnc lathe when they go out
Powder coated steel enclosure, 1/4" Surface grounded hardened aluminum plate, MK2A Heat bed, .200 Polished fused quartz plate, Machined quick change hot bed mount, E3D hot end, Ramps 1.4, DRV8825 stepper motor drivers