Hello knowledgeable ones! I need your help to make my life easier; Background. I need to turn on fans every cold night during winter in a grain storage shed to keep the grain from heating/rotting! This involves treking to the shed in the cold after midnight (cheap electricity) and flipping 2 circuit breakers on the wall to activate the fans... The fans are just single phase induction motors (around 1.7kw) which plug directly into a standard electrical outlet (240v). The Motors on the fans each have a black box with all the bits nescessary for them to start up etc. The Idea. I want to build a device containing a clock and a temprature sensor, which will close a contact after midnight if the temprature is less than 6 deg c. and open the contact at 7am The idea is that you would plug this device into the wall outlet and plug the fan into the device. HELP: I've figured what i need to make and break the circuit is something called a CONTACTOR, but i'm stumped as to what one i need. The Clock and temprature sensor would be implemented on a microcontroller which would give the signal to the contactor to start the fans. So basically i need a device that would take a low voltage DC input (prob 9V or less) and close a switch to carry about 7A at 240Vac. Any ideas?