What additional requirement is necessary for conductors of dissimilar metals when mixed?

When dealing with conductors made of dissimilar metals, it is crucial to use identified devices for the specific purpose and conditions of use. This requirement ensures that the devices are suitable for the types of metals being used and the application they are intended for.

Using devices specifically designed for dissimilar metals helps prevent issues such as galvanic corrosion, which can occur when two different metals come into contact in the presence of an electrolyte, leading to degradation of one of the metals. Identified devices ensure proper compatibility and function, contributing to the overall safety and reliability of the electrical installation.

The other choices do not address the critical aspect of ensuring that the devices are identified and appropriate for the specific conditions in which dissimilar metals are combined. Insulated devices or supplementary bonding may have their roles, but they do not specifically tackle the compatibility issue that arises from mixing different types of conductors. Therefore, selecting the right identified devices is essential for achieving a safe and effective electrical system when working with dissimilar metals.