Arrived onsite for no cooling in first floor system. Performed diagnostic. Found no signal to outside system. Found fault electrical safety circuit. Blown 5 amp fuse. Used resettable fuse to test the system. The system started up and ran fine. Replaced 5 am fuse. Monitor system for faults…none were detected. If the fuse continues to blow; we can perform thorough diagnostic on the electrical system looking for power surges and shorts. System running as it should.