Making a 4 way switch, multiple options

Question

Refactoring the question as requested:

I'm doing a small home automation project. The circuit I'm trying to control using an ESP8166 is this:

LOAD: 220VAC / 1A

To be able to control the circuit using the ESP and the mechanic switches, I need to plug a 4-way switch in the middle. Something like this:

My idea is to use a latching DPDT relay with crossover NO/NC, like this:

So, in the end, I'll have something like this: (minimal schematic, missing protection circuits, external source for relay, relay in's, ..)

^{simulate this circuit – Schematic created using CircuitLab}

My main question is: Is this correct ?

My second question is: Is it possible/better to use a mosfet+bridge rectifier instead of the relay since 1. a mosfet switches faster, 2. the relay wears-off faster

Answer 1

Decent sealed relays are typically guaranteed to withstand something like 100K cycles with a resistive load, which means they can switch on and off every hour and still have a 10+ years lifetime. Unless you need to switch your load repeatedly each minute or more often, I'd advise you to stick with relays.

You also say that MOSFETs switch faster than relays, which is true. However, I'm having a hard time picturing a load for which a delay of 50ms or less would be problematic.

Finally, MOSFETs + bridge rectifier will work with an incandescent lamp, but more sophisticated loads may require proper AC waveform to function correctly. Commutation of a sinusoidal signal with MOSFETs will be much more complicated than with relays (you'll probably end up rectifying AC to DC, doing commutation in DC and install inverters at each load which needs AC).