Pool lights 12v sonoff 4ch r2

Hello guys,

I have connected my pool lights with a Sonoff 4ch pro (r2). I made the link between sonoff and smartthings with IFTT and everything works nice.

The thing is that this pool lights have to work on 12v for safety reasons. So my pool has a transformer that converts my 220 AC electricty to 12v to send to this lights.

I connected the sonoff between the transformer and the lights, each light to one relay of sonoff. My question is:

Could be the sonoff changing my voltage in between the transformer and the lights? Since the lights work i dont know if this is possible. I want to be sure for safety reasons. (sonoff main power is powered by 220v)

Also i see each pool light is consuming like 40w. I dont know if this is too much and has anything to do with the sonoff.

Thanks and sorry for my bad english.