IEEE 463:2019 pdf free download – IEEE Standard for Electrical Safety Practices in Electrolytic Cell Line Working Zones
The cell line working zone shall not be required to extend through or beyond walls,floors, roofs, ceilings,partitions, barriers, or the like.
Note that each cell may have attachments and auxiliary equipment, which are electrical extensions of thecells that can be hazardous.Examples of these extensions include piping and the associated fluids within,. cellframes,instrumentation, and electrical disconnect switch. Each of these extensions should be identified andrecognized at each plant so the electrical hazard is clearly understood.
5. lmproved safeguarding of personnel from electrical hazards within thecell line working zone
Operation and maintenance of electrolytic cell lines routinely requires personnel to contact exposedelectrically energized surfaces such as electrolytic cells, their energized attachments and dc bus. The potentialrisk of injury due to electrical hazards presented by these energized surfaces can be reduced or minimized bythe 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 taskswithin 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 cellline 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 nonconductivematerials. Nonconductive material may include glass, porcelain, epoxy coating, rubber, fiberglass, plastic, andwhen 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 cellline energized surfaces and ground is required. The electrical insulation systems on fixed and movableequipment within the cell line working zone shall be tested periodically and monitored to help ensure theinsulating 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 membersfrom grounded members. Additional safeguards (listed in Clause 5) may be warranted based on a task basedrisk assessment of the task being performed.
5.2 Guards
Guards include mechanical devices such as covers, casings, barriers,rails,screens, mats, and platforms thatprevent 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,cither directly or through a resistance, so that there is insufficient voltage difference, helping to reduce the riskof an electrical hazard.
5.4 lsolation
Isolation employs the placement of equipment or items in locations so that personnel are unlikely tosimultaneously 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 lessthan that defined for the cell line working zone.
6.6 Nonelectrical components
Air hoses,water hoses, and other auxiliary nonelectrical connections to an electrolytic cell, its energizedattachments, or auxiliary equipment shall not have continuous, conductive, reinforcing wires; armors; braids;or other similar materials.Hoses shall be constructed of a nonconductive material suitable for use with the cellline voltage.
6.7 Typical cell line working zone applications of safeguards where electricalhazards exist
A person is working on an cnergized cell. Manual contact is required to make adjustments and repairs. Theexposed energized cell surfaces and ground are likely to creatc an clectrical hazard.A shock andor arc flashhazard risk assessment shall be consulted or performed.One or more of the following methods shall be utilizedfor personal protection:
a)Apermanent or temporary insulating surface on which the pcrson stands.
b)Modification to the design of the installation provides an ungrounded conductive surface on which the person stands. If this conductive surface is bonded to the cell, the electrical hazards are minimized andimproved safety provided.