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.
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.
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.