IEEE Std 844.4™-2019/ CSA C293.4:19 (R2024)

This standard provides for the application of impedance heating systems for steel or steel alloy pipe and equipment. It provides recommendations for design, installation, maintenance, and repair of these systems in general industry applications. This standard applies to impedance heating systems intended to be installed in ordinary and hazardous locations with explosive atmospheres. The hazardous locations 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, when used with other recognized codes and standards, is intended to cover impedance heating systems in their entirety, including system design, specification, installation, operation, testing, commissioning, and maintenance. This document also addresses the following associated systems that are important to the performance of impedance heating systems: a) Thermal insulation systems; b) Electric power supply systems; c) Electric grounding systems; and d) Control and monitoring systems.