SE cable used to supply ___ shall not be subject to conductor temperatures in excess of the temperature specified for the type of insulation involved.

The correct answer pertains to the usage conditions of Service Entrance (SE) cable. SE cable is designed to perform under specific environmental and thermal conditions dictated by the type of insulation used. When supplying outdoor equipment, which is typically exposed to varying weather conditions and possibly direct sunlight, it is crucial to ensure that the conductor temperatures do not exceed the limits set by the insulation material.

Outdoor applications often involve harsher temperature fluctuations and the potential for increased heat exposure compared to indoor uses. This makes the management of conductor temperatures particularly important, as exceeding insulation temperature ratings can lead to insulation breakdown and potential electrical failures.

In contrast, lighting fixtures, appliances, and indoor outlets may not face the same level of thermal strain as outdoor equipment since they are generally installed in more controlled environments. Thus, while those applications also require compliance with temperature ratings, the unique challenges presented by outdoor environments necessitate stricter adherence to conductor temperature limits for SE cable supplying outdoor equipment.