Responded to call for upstairs air handler not operating. Upon arrival customer advised hvac tech has already responded and determined air handler did not have proper voltage. Inspected. Found one phase to unit is lost. Inspected breaker. Found defective breaker has started to burn the circuit wire. Inspected sub panel. Found sub panel was fed with 6 gage 2 wire and was powered with 40 amp breaker. Found bus bars in sub panel have over heated due to improper service for load. Advised customer of all findings. Customer agreed to option. Replaced all circuit breakers in main panel. Separated all double tapped neutrals in main panel. Installed new 2 gage 4 wire feed for sub panel. Replaced sub panel. Installed all new breakers in sub panel. Relocated dryer circuit from main panel to sub panel. Tested all installs. All are operating properly at this time. Power restored to upstairs air handler. Found no other issues at this time. Customer is 100% satisfied with today’s service. Tha