Thermostat c wire not connected at HVAC end

Like every other idjit I'm trying to install a Nest thermostat, wired everything up like the old unit, didn't detect the C wire. I discovered it's not attached to anything in the HVAC unit. It looks like they have a condensation cutoff switch attached to the hvac R and the other end to the condensate pump which connects to the thermostat Rc? This setup REALLY doesn't seem right. Everything I've seen puts the switch interrupting the C line. While I feel like I COULD get away with just attaching it to the C post, I'm not sure it's functioning correctly as is.