Bus plugs connect to a busbar or busway to provide a localized power distribution to electronic devices, while protecting and supplying power to industrial equipment. Circuit protection for bus plugs may be in the form of a circuit breaker or a f. Bus plugs connect to a busbar or busway to provide a localized power distribution to electronic devices, while protecting and supplying power to industrial equipment. Circuit protection for bus plugs may be in the form of a circuit breaker or a fuse. Fused or circuit breaker bus plugs may be used in conjunction with different types of bus ducts and. There are three main types of bus plugs. Other types of bus plugs may also be available. 1. Disconnect switchbus plugs, or disconnects, rapidly interrupts and disconnects current flowing through an electrical device in event of an emergency. 2. Tap boxesare enclosure devices that connect power cable feeds to a busway system. Tap boxes are commonly. When selecting bus plugs, it is necessary to ensure the voltage rating and conductor configuration matches the plug. Bus plug voltage ratings commonly range from 120/40, 208-120, 240, 277/480, 480, and 600 in the United States. Ampere ratings may range from 15-to-600 amps. The most commonly used bus plug ampere ratings fall between 30-200 amps, wit.