Performed diagnostic on commercial package unit. Thermostat is not turning on and unit is not working. Checked for power at the thermostat, not getting any low voltage power. Went up on roof and checked system electrical and components. System is not recieving power at all. Verified all fuses are working correctly. Checked electrical panel at warehouse and found 3 pull breaker to be turned off. Was not tripped it was completely shut off. Turned breaker on and restored operations to unit. Went over findings and recommendations. They are just tenants and can not make any decisions. Going to let the owner of the building know. System operational upon departure.