Powerbus busway delivers scalable and flexible overhead power distribution. Simple modularity minimizes unintended downtime. Units are available in 100A, 225A, and 400A as well as up to 600V maximum rating. Powerbus busway uses the same Plug-in Units across all busway ampacities. This unit is Plug-in unit with 3 spaces for QO/QOB circuit breakers that is rated at 100A. The busbar configuration for this plug-in unit is 4A. All busway rating are listed to UL 857 Busway Standard for Safety.