Breaking the grounded conductor in a timer?

[ultramegabob]

I have several commercial buildings that I have done work in that the timer is wired so it breaks the grounded conductor to the photo eye, then the switch leg from the photo eye is connected to the coil on the contactor. Has anyone else seen a setup like this?

 

[Pierre C Belarge]

That is the cheap way to wire these, eliminating a 3-wire setup.