IEEE Std 463-2019 pdf free download – IEEE Standard for Electrical Safety Practices in Electrolytic Cell Line Working Zones.
5. Improved safeguarding of personnel from electrical hazards within the cell line working zone
Operation and maintenance of electrolytic cell lines routinely requires personnel to contact exposed electrically energized surfaces such as electrolytic cells, their energized attachments and dc bus. The potential risk of injury due to electrical hazards presented by these energized surfaces can be reduced or minimized by the selection and use of appropriate safeguards. Exposed energized surfaces of cells and attachments in themselves do not necessarily create electrical hazards. However, simultaneous contact between surfaces operating at different potentials, including ground potential, could create an electrical hazard.
Therefore, safeguards shall be provided for personnel performing work tasks within the cell line working zone. Safeguards shall be provided by one or a combination of the means described in 5.1 through 5.10. In some cell line installations, certain safeguards are inherent due to building size, equipment spacing, component type, materials of construction, etc.
5.1 Insulation
Insulation includes a properly designed system for energized and/or grounded surfaces utilizing nonconductive materials. Nonconductive material may include glass, porcelain, epoxy coating, rubber, fberglass, plastic, and when dry, such materials as concrete, tile, brick, and wood.
Periodic testing and monitoring of the insulation integrity used in the cell line work zone from the cell line energized surfaces and ground is required. The electrical insulation systems on fxed and movable equipment within the cell line working zone shall be tested periodically and monitored to help ensure the insulating properties do not degrade to a state that the equipment becomes unsafe to use.
Personnel working on or around an electrolytic cell line may mistake cell line potential and insulated members from grounded members. Additional safeguards (listed in Clause 5) may be warranted based on a task based risk assessment of the task being performed.
5.2 Guards Guards include mechanical devices such as covers, casings, barriers, rails, screens, mats, and platforms that prevent approach or contact with electrically energized or grounded surfaces.
5.3 Voltage equalization Voltage equalization is accomplished by connecting a conductive surface to an electrically energized surface, either directly or through a resistance, so that there is insuffcient voltage difference, helping to reduce the risk of an electrical hazard.
5.4 Isolation Isolation employs the placement of equipment or items in locations so that personnel are unlikely to simultaneously contact exposed conductive surfaces at different potentials.
5.5 Physical clearance Physical clearance is a substantially safe working distance designed to minimize safety risks that may be less than that defned for the cell line working zone.
5.6 Personal protective equipment Personal protective equipment (PPE) should include one or more of the following as determined appropriate for the conditions:
— Footwear for wet service
— Footwear for dry service
— Gloves for wet service
— Gloves for dry service
— Sleeves for wet service
— Sleeves for dry service
— Electrically insulated head protection
— Eye protection with nonconductive frames
— Faceshield (polycarbonate or similar non-melting type)
— Other PPE as required
Consideration should be given to the tasks being performed (Task Based Risk Assessment) as well as the rating of the PPE selected for the task, versus the potential exposures in the vicinity of the work being performed.IEEE Std 463 pdf download.