Lately, the electrical industry in Canada has been buzzing about newly developed CSA standard Z462 which covers requirements for workplace electrical safety.
There are many in the industry who feel that this standard will impact on electrical work done under provisions of the CE Code, and that this standard will immediately affect electrical contractors involved in various installation projects across the country.
In fact, theIAEI Newshasmentioned the new CSA standard in order to raise awareness of this important safety document.
So, let’s take a look at the relationship between Z462 and the CEC, Part I.
The object of the CE Code, Part I is formulated in the Code as follows:
The object of this Code is to establish safety standards for the installation and maintenance of electrical equipment. In its preparation, consideration has been given to the prevention of fire and shock hazards, as well as proper maintenance and operation.
Compliance with the requirements of this Code and proper maintenance will ensure an essentially safe installation.
The object of the Code is to provide safety of persons, livestock and property against hazards and damage which may arise in the reasonable use of electrical installations.
The object of the CE Code, Part I appears to clearly state that compliance by the users with prescriptive installation provisions of the Code will yield the intended safety. It should be noted that rules of the CE Code govern technical installation requirements related to fundamental safety principles of protection against electric shock by preventing direct and indirect contact with live parts of the installations, of protection against thermal effects, against fault currents, overcurrents and overvoltages.
These rules of the Code deal with selection of overcurrent protective devices and disconnecting means, conductors for electrical equipment, wiring methods, installation of various types of electrical equipment and with equipment bonding and grounding means.
The CE Code does not specifically cover requirements for all relevant safe work practices during electrical installations, as such safe work practices (use of safety boots, hard hats, safety glasses, etc.) are governed by particular standards and regulations, and these safe work practices are not necessarily limited to the workers involved in electrical installations.
However, the CE Code contains a set of rules that cover maintenance and operation of electrical equipment.
For example, Rule 2-300(1) requires that:
All operating equipment shall be kept in safe and proper working condition.
Rule 2-304 is dedicated to disconnection of electrical equipment, and it clearly requires that no maintenance work be undertaken on live equipment unless complete disconnection of the equipment is not practicable (i.e., voltage testing, adjustments of relay settings, etc.).
This rule also requires use of adequate means to prevent electrical equipment from being energized when such maintenance work is conducted.
No repairs or alterations shall be carried out on any live equipment except where complete disconnection of the equipment is not practicable.
Three-way or four-way switches shall not be considered as disconnecting means.
(3) Adequate precautions, such as locks on circuit breakers or switches, warning notices, sentries, or other equally effective means, shall be taken to prevent electrical equipment from being electrically charged when work is being done.
The current edition of the CE Code has been amended by introduction of Rule 2-306 — to mandate warning of qualified persons involved in a maintenance work on energized equipment.
2-306 Shock and flash protection (see Appendix B)
(1)Electrical equipment such as switchboards, panelboards, industrial control panels, meter socket enclosures, and motor control centres that are installed in other than dwelling units and are likely to require examination, adjustment, servicing, or maintenance while energized shall be field marked to warn persons of potential electrical shock and arc flash hazards.
(2) The marking referred to in Subrule (1) shall be located so that it is clearly visible to persons before examination, adjustment, servicing, or maintenance of the equipment.
Appendix B Note on this rule references standard NFPA 70E, Electrical Safety in the Workplace for necessary assistance in determining severity of potential exposure, for preparation of safe work practices and for selection of personal protective equipment — to protect workers against shock and arc flash hazards. Appendix B Note on this rule also indicates standard IEEE 1584 as a guide in determining the incident energy to which workers may be exposed and in calculating the arc flash hazard distance relative to the incident energy.
This means that when a worker is doing electrical work under technical provisions of the CE Code, but this work also involves functions that might require the equipment to be energized, then safe work practices around energized electrical equipment (in addition to wearing safety boots, etc.) must also meet applicable provisions of NFPA 70E.
As Rule 2-306 (and Appendix B Note) has been in the 2006 CE Code for quite some time, it is expected that the electrical workers already meet safety provisions of all relevant standards when they work around energized equipment.
So, what has changed with the development of Z462?
Actually, not much has changed for the electrical contractors involved in construction projects. The CSA has developed the new standard Z462 Workplace Electrical Safety, and this standard will be now referenced in Appendix B Note on Rule 2-306 of the 2009 edition of the CE Code instead of NFPA 70E.
However, this standard is not directly mandated under installation requirements of the CE Code. When this standard is adopted by various regulatory bodies that administer occupational health and safety, such AHJs will administer compliance with Z462, when electrical work is done on energized equipment.
Z462 is a first Canadian standard which addresses electrical safety requirements for workplaces that are necessary for the practical safeguarding of workers during electrical work on or around energized electrical equipment.
This standard specifies requirements for and provides guidance on safety management systems and safe work procedures for persons working on energized electrical equipment and electrical systems. It also provides direction on the selection of personal protective equipment and other safety devices for electrical workers. In addition, this standard sets out criteria for the identification and training of qualified electrical workers and for determination of hazardous work to be performed only by those qualified individuals.
Except for a very specific work that involves a necessary (unavoidable) maintenance of live equipment, all electrical installations undertaken under rules of the CE Code are done only on de-energized equipment.
Therefore, it would be very unlikely to see a typical electrician doing electrical installation under a permit on a construction site wearing a PPE required by Z462.
However, when plant electricians are involved ina maintenance and operation work under a scope of their annual maintenance or operating permit, such work (when performed on live equipment) would have to meet safety provisions of Z462. It should be noted that the latter provisions are not necessarily administered by the electrical safety authorities who enforce the CE Code for regulatory purposes.
CE Code governs safety requirements for installation of electrical equipment.
Such electrical work must be done by the construction electricians under electrical permits and is subject to the inspection services by regulatory authorities.
Under no conditions is such work permitted to be done on live equipment.
However, the CE Code also regulates provisions for maintenance and operation of operating equipment, and although Rule 2-304 does not allow such maintenance on live equipment, it recognizes that sometimes a completed disconnection of the operating equipment is not practicable for certain repairs, alterations or testing.
For this reason, Rule 2-306 has been introduced into the 2006 edition of the CE Code. This rule mandates installation of warning signs of potential shock and arc flash hazards on electrical equipment. Explanatory Note in Appendix B on this rule leads the users of the CE Code (who intend to maintain live electrical equipment) to NFPA 70E and to IEEE 1584 in order to determine severity of exposure, to evaluate the arc flash hazard distance and incident energy resulting from the arc, and to select personal protective equipment appropriate for the anticipated incident energy — to protect against shock and arc flash hazards.
With the development and publication of the Canadian standardZ462 Workplace Electrical Safety, 2009 edition of the CE Code will lead the code users (who intend to maintain live electrical equipment) in Appendix B Note on Rule 2-306 to Z462 for safe work practices around energized equipment.
In the city of Vancouver, all applicants for installation permits are aware that thepermit holders cannot work on live equipment, and the city of Vancouverdoes not provide inspection services on live equipment.
Only maintenance electricians, who test, alter or repair live equipment would have to meet all applicable provisions of Z462, and such work is done under an operating/maintenance permit.
And as usual, the readers should check specifics of this subject with the local authorities.
Read more by Ark Tsisserev