Background

A California utility provides electrical power to one of their Customers via an underwater cable. The cable passes from the mainland, under the harbor (for approximately one mile) to a critical use Customer.

Problem

With a continuously increasing demand for electrical power by their Customer, coincident with seasonal warming harbor waters, it was deemed prudent to gather empirical data on the cables temperature rise to confirm Engineering calculations.

Solution

A Logic Beach data logger was employed with thermocouple sensors to monitor the long term temperatures along a representative section of the cable. The logger was mounted in an access "hand hole" near the bank of the harbor. Powered by its internal battery pack for months, temperature data was logged.

Cable temperature rise data was collected throughout the year and correlated with metered power, tidal flow and ambient temperature conditions. Resulting empirical data confirmed the Engineering calculations.