This recommended practice provides detailed recommendations for the testing, design, installation, and maintenance of electrical resistance heat tracing in commercial applications. Commercial applications include installations inside and outside of commercial business buildings, such as office buildings, hospitals, and airports. Typical applications include freeze water pipes; temperature maintenance of hot water piping and other lines and tubing; protection of sprinkler systems; roof, gutter, and pavement deicing; and other applications as shown in table . The recommendation also include test criteria to determine the suitability of heating cables and fittings that are utilized for these applications. Commercial applications involving hazardous (classified) locations should meet the requirements in IEEE Std 515-1989 in addition to the requirements in this document.