What does the cryptic crossword clue "Electrical unit Lou turned into locks’ maintenance device (7)" mean?

The wordplay uses an anagram. anagram of LOU (synonym="LOU") + COMB (synonym="locks maintenance device") = COULOMB The answer is COULOMB.

Electrical unit Lou turned into locks’ maintenance device (7)

Guardian Cryptic #29462 | 5 Down | 2024-08-15 flower