For this eval I showed up to the customer's home and was informed the unit has not been working since january. Upon going into the attic I noticed this house is operated via a zone system and the fuse was popped. I replaced the fuse and jumped R&Y. After doing this the system ran for approximately 30 seconds and then popped the fuse again. Upon this happening I went to the condenser and the condenser was not running, I tested voltage and was getting 240 on the lower legs, but no voltage on the top or bottom because the contactor was not engaged, signifying there was no call from the thermostat. I checked the thermostats again and they were both in cooling and set to 68°, I went back to the Attic and tested the transformer and was getting 120 volts but no 24 volt call. I changed out the transformer and the system ran for another 30 seconds and popped another fuse. I tested voltage again on the bus bar at C&Y and R&Y with no voltage reading. I went back to the condenser and swapped out