I'm confused weather I should go for a standard electromechanical relay (EMR) or a sold state relay (SSR) to switch CFLs @ 220V with 100W max load. This is for a commercial product with the following objectives:
- Have at least 7 years of life (of continuous use)
- Resilient to short-circuits at the outputs of it's switching device (SSR, EMR or TRIAC).
The main concern here is the failure of the device: SSR will provide an extremely long life (if other components are up to it) whereas a EMR will have a relatively shorter life-span. However, it seems EMRs are more rugged to a short-circuit (till the circuit breaker or fuse pops, at least). A failure mode of CFLs I've found is that they sometimes short-circuit – either the internal wiring insulation fails or some other type of fault due to sub-standard components).
I suppose the question becomes: how long can I expect an EMR with a resistive electrical contact life of 100,000 cycles to work if the relay is switched 10 times a day?
Alternate approach that I had in mind: use a large TRIAC (rated for 30+ amps continuous) and a resettable fuse, rated for 500 mA, in conjunction with it. The fuse interrupts the current flow thereby saving the TRIAC from damage. Since the TRIAC is a heavy-duty one it has a higher likelihood of surviving such a failure.
Will the TRIAC allow me to have my cake and eat it too?