This part of IEC/IEEE 62395-2 provides detailed recommendations for the system design, installation, maintenance and repair of electrical resistance trace heating systems in industrial and commercial applications. This standard does not include or provide for any applications in potentially explosive atmospheres. This standard pertains to trace heating systems that may comprise either factory fabricated or field-assembled (work-site) units, and which may be series or parallel trace heaters, or surface heaters (heater pads or heater panels) that have been assembled and/or terminated in accordance with the manufacturer's instructions. The products covered by this standard are intended to be installed by persons who are suitably trained in the techniques required and that only trained personnel carry out especially critical work, such as the installation of connections and terminations. Installations are intended to be carried out under the supervision of a qualified person who has undergone supplementary training in electric trace heating systems. This standard does not cover induction, impedance or skin effect heating. Trace heating systems can be grouped into different types of installations. These are characterized by different requirements for testing and are usually certified for a specific type of installation or application. Typical applications for the different types of installation are as follows: a) Installations of trace heating on pipes, vessels and associated equipment. Applications include : - freeze protection and temperature maintenance; - hot water lines; - oil and chemical lines; - sprinkler systems. b) Outdoor exposed area installations of trace heating. Applications include: - roof de-icing; - gutter and downspout de-icing; - catch basins and drains; - rail heating. c) Installation with embedded trace heating. Applications include: - snow melting; - floor warming; - frost heave prevention; - underground thermal energy storage systems; - door frames. d) Installations of trace heating internal to conduit or piping. Applications include: - snow melting - in conduit; - floor warming - in conduit; - frost heave prevention - in conduit; - underground thermal energy storage systems - in conduit; - internal trace heating of potable water lines; - enclosed drains and culverts.