These three items may be interpreted differently.
공구손료: tool wear and tear cost (손료=損料 wear and tear cost)
저압케이블공: "low voltage cable work" or "low voltage cable electrician"
고압케이블공: "low voltage cable work" or "low voltage cable electrician"
(압 may mean voltage, pressure, tension, etc)
To be sure, one needs to see the whole document, especially if it has Chinese characters.