Evaluating 90 °C vs. 105 °C Rated Cables

This technical white paper evaluates the performance of 90 °C and 105 °C rated cables in underground residential distribution systems. It discusses the implications of choosing between these two temperature ratings, highlighting that while 105 °C cables may offer higher ampacity, they also present significant drawbacks. The paper outlines a thermal performance study that compares ampacity ratings and losses associated with both cable types. It details how operating at higher temperatures can lead to increased conductor and concentric wire losses, which can affect overall system efficiency. Additionally, the paper addresses accessory compatibility, noting that connectors and terminations must be selected based on the cable's operating temperature to prevent overheating and failure. The conclusion emphasizes the importance of considering soil thermal stability when direct burying cables, indicating that 90 °C rated cables provide a more reliable and efficient solution for power distribution applications. The findings are supported by various studies and standards referenced throughout the document.