As a general rule, the bus bars arerated on the basis of not more than 800 A/in.2 of aluminum or 1000 A/in.2 of
copper. The operation of protective devices is based upon an ambient temperature
of 40 °C, and if these devices are to be applied at higher temperature,
the manufacturer should be consulted. The short-circuit rating of a bus
is limited to the interrupting rating of the lowest rated protective device, and
the available short-circuit current should not exceed this value.