CSA C22.2-NO.88:2019 pdf download.Industrial heating equipment
3.5 Specific components shall be considered as incomplete in construction features or restricted in performance capabilities. Such components are intended for use only under limited conditions, such as certain temperatures not exceeding specified limits, and shall be used only under those specific conditions for which they have been investigated.
3.6 A product that contains features, characteristics, components, materials, or systems that are new or different from those covered by these requirements and that involves risk of fire, electric shock, or injury to persons, shall be evaluated using the appropriate additional component and end product requirements as determined necessary to maintain the acceptable level of safety as originally anticipated by the intent of these requirements. A product whose features, characteristics, components,materials or systems, conflict with specific requirements or provisions of this Standard shall not be judged to comply with those requirements.
4.1 General
Industrial heating equipment which must be field assembled on installation because of its size shall be designed so that a minimum of assembly is necessary and that in completing the assembly in the field,wiring and other electric parts are unlikely to be damaged.
4.2 Enclosures for live parts
4.2.1 General
Enclosures for live parts shall be formed and assembled so that they will
a) have the strength and rigidity necessary to resist the abuses to which they might be subjected,without increasing the fire or accident hazard due to deformation of the enclosure with resulting reduction of spacing, loosening, or displacement of parts, etc.;
b) afford protection against accidental contact with live parts, except in the case of recessed open-wire heating elements; and
c) afford protection for electrical components against the deleterious effects of excessive moisture,steam, chemicals, or other material which might be encountered in operation of the equipment.
4.2.2 Material
Enclosures shall be of incombustible material and shall be judged with respect to size, shape, thickness of material, extent of framing, and suitability for the application. In general, enclosure material shall be of such thickness or so reinforced as to give stiffness and protection equivalent to that obtained if blank, flat steel not less than 0.78 mm thick were used, except for glass, glass cloth, or similarly enclosed heating elements (e.g., infrared lamps) which are acceptable if they comply with Clause 4.10.3.
4.3.1 Iron and steel parts shall be provided with a means to reduce the likelihood of corrosion, such as enameling, galvanizing, and plating, if the corrosion of such unprotected parts would be likely to result in a risk of fire, electric shock, or injury to persons.
Notes:
1) In certain instances in which the oxidation of iron or steel resulting from the exposure of the metal to air and moisture is not likely to be appreciable and the thickness of metal and temperature are also factors, surfaces of sheet-steel and cast-iron parts within an enclosure might not be required to be protected against corrosion.
2) Bearings, laminations, or minor parts of iron or steel, such as washers and screws, need not be protected against corrosion.CSA C22.2-NO.88 pdf download.