PSI Journeyman Online Practice Exam

The conductors from the generator terminals to the first distribution device(s) must be rated for 115% of the nameplate current rating. This requirement ensures that the conductors can handle inrush currents and any temporary overloads that might occur during the generator's operation. By sizing the conductors to this percentage above the nameplate rating, it promotes safety and reliability in the electrical system, allowing for adequate thermal protection while minimizing the risk of overheating and potential failure. This precaution is particularly important in scenarios where generators are frequently started or under varying load conditions, providing a buffer against the current fluctuations that can arise.

In contrast, the other options do not adequately account for these safety considerations. For instance, rating the conductors at 100% might not provide sufficient capacity to handle the potential inrush current. Similarly, options like 110% or 120% do not align with the standard practices in electrical engineering regarding conductor sizing related to generator outputs, as they either underestimate or overestimate the required rating. Therefore, 115% is the appropriate and standard practice for ensuring the conductors are properly rated for safety and performance.