I have been getting a fault on the roof top chiller for the 2 tandem 7.5 ton chillers. I have checked and we have water flow and the temperatures are nowhere near freezing. I believe they are over heating as the fans on that side are not coming on. The blades are free to turn by hand but the VFD controller keeps saying off. I have tried turning it on and off and that also did nothing. I have contacted ESC for further advice.