Ensure the main power supply is turned off at the circuit breaker or main switch before starting any work. Governed by Article 230 of the National Electrical Code, its job is to cut off all power coming from the utility's service drop (overhead) or service lateral (underground). And all the switching and protective devices are installed in the distribution box. Single Phase Distribution Box generally consists of Double Pole MCBs, Single Pole MCBs, and RCCBs. Proper setups ensure balanced electrical loads, ground fault protection, and easy maintenance. Common configurations include single-phase for homes and three-phase for. Installing a service disconnect is an essential step in the process of wiring any electrical system.