How should control cabinet be specified for industrial heating elements?

Specify the control cabinet from actual duty: size breakers, contactors or solid-state relays by the elements' total current and inrush, then verify busbars, cable cross-section and cabinet cooling so internal temperature rise stays within component limits. Check protection rating, mounting and the temperature-control loop separately from the power circuit, and allow for thermocouple and over-temperature inputs. On the first article, measure current balance, surface load and temperature rise, then freeze drawings and tolerances before bulk ordering.