I. General
and wiring are designed and approved for the hazardous (classified) locations.
665.5 Output Circuit. The output circuit shall include all output components external to the converting device, including contactors, switches, busbars, and other conductors. The current flow from the output circuit to ground under operating and ground-fault conditions shall be limited to a value that does not cause 50 volts or more to ground to appear on any accessible part of the heating equipment and its load. The output circuit shall be permitted to be isolated from ground.
665.1 Scope. This article covers the construction and in stallation of dielectric heating, induction heating, induction melting, and induction welding equipment and accessories for industrial and scientific applications. Medical or dental applications, appliances, or line frequency pipeline and vessel heating are not covered in this article.
FPN: See Article 427, Part V, for line frequency induction heating of pipelines and vessels.
665.2 Definitions.
Converting Device. That part of the heating equipment that converts input mechanical or electrical energy to the voltage, current, and frequency suitable for the heating applicator. A converting device shall consist of equipment using mains frequency, all static multipliers, oscillator-type units using vacuum tubes, inverters using solid-state devices, or motor generator equipment.
Dielectric Heating. Heating of a nominally insulating material due to its own dielectric losses when the material is placed in a varying electric field.
Heating Equipment As used in this article, any equipment that is used for heating purposes and whose heat is generated by induction or dielectric methods.
Heating Equipment Applicator. The device used to transfer energy between the output circuit and the object or mass to be heated.
Induction Heating, Melting, and Welding. The heating, melting, or welding of a nominally conductive material due to its own I 2R losses when the material is placed in a varying electromagnetic field.
665.3 Other Articles. Unless specifically amended by this article, wiring from the source of power to the heating equipment shall comply with Chapters 1 through 4.
665.4 Hazardous (Classified) Locations. Heating equip- ment shall not be installed in hazardous (classified) locations as defined in Article 500 unless the equipment
665.7 Remote Control.
(A) Multiple Control Points. Where multiple control points are used for applicator energization, a means shall be provided and interlocked so that the applicator can be energized from only one control point at a time. A means for de-energizing the applicator shall be provided at each control point.
(B) Foot Switches. Switches operated by foot pressure shall be provided with a shield over the contact button to avoid accidental closing of a foot switch.
665.10 Ampacity of Supply Conductors. The ampacity of supply conductors shall be determined by 665.10(A) or (B).
(A) Nameplate Rating. The ampacity of conductors supplying one or more pieces of equipment shall be not less than the sum of the nameplate ratings for the largest group of machines capable of simultaneous operation, plus 100 percent of the standby currents of the remaining machines. Where standby currents are not given on the nameplate, the name-plate rating shall be used