Three-phase power enters each controller through separable connectors. The motor is wired to terminals in the controller. MCCs provide wire ways for field control and power cables. Each motor controller in an MCC can be specified with a range of options such as separate control transformers, pilot lamps, control switches, extra control terminal blocks, various types of bi-metal and solid-state overload protection relays, or various classes of power fuses or types of circuit breakers. An MCC can either be supplied ready for the customer to connect all field wiring or can be an engineered assembly with internal control and interlocking wiring to a central control terminal panel board or programmable controller. An MCC is generally mounted on floors, which are often required to have a fire-resistance rating. Fire stops may be required for cables that penetrate fire-rated floors and walls.

An Intelligent MCC uses a smart, electronic protection device in lieu of a conventional thermal overload device, to accommodate various protection functions, depending on configuration and software. However, each control unit uses devices that have embedded intelligence. Specifically, PLC, Soft Starters, circuit breakers, contactors, and AC Drives can provide information over an internal network which can further support communication networks to higher level systems in the operation. Most common network supported outside of the cabinet includes Profibus, ProfiNet, CCLink, Ethernet\IP, DeviceNet or Modbus). This communication link is often connected directly to the PLC mounted inside the cabinet. The PLC performs protection, communication, control, and monitoring functions.