All units have a main power panel that is stubbed out through the bottom of the unit. Each is pre-wired, eliminating the need for any internal wiring. The main breaker in sizes 8’ wide office trailers will require a 60 amp service with a voltage of 220. The main breaker in sizes 10’ & 12’ wide office trailers will require a 100 amp service with a voltage of 220. A certified electrician is required to connect electricity. Customer is responsible for any damages incurred.