IEEE Std 844.3™-2019/ CSA C22.2 No. 293.3:19 (R2024)

This standard applies to general, testing, marking, and documentation requirements for impedance heating systems for steel or steel alloy pipe or equipment, rated up to and including 132 Vac. These heating system components are intended for installation in accordance with CSA C22.1, Canadian Electrical Code, Part I (CE Code); NFPA 70, National Electrical Code® (NEC®) in the USA; or with any other national electrical installation code, as applicable. This standard applies to impedance heating systems that are intended to be installed in ordinary and hazardous locations. The hazardous location installations are limited to 30 Vac and include the following: ? In Canada: Zone 2; Zone 22; or Class I, Division 2; Class II, Division 2; Class III, Division 2 as described in CSA C22.1; and ? In the USA: Class I, Zone 2; Zone 22; or Class I, Division 2; Class II, Division 2; Class III, Division 2 as described in the NEC. This standard also applies to power connection points and control methods used with impedance heating systems. NOTE 1— Requirements for certification of insulated impedance conductors with insulation temperature ratings above 105 °C may be considered under a special investigation by an accredited certification body. NOTE 2— Information on isolation transformers, power distribution, and control components can be found in IEEE Std 844.4/CSA C293.4.