Personnel And Equipment Safety

Personnel & Equipment Safety Introduction: safety issues can be classified broadly into safety of personnel and safety of equipment. The persons dealing with the electrical equipment have to be cautious & follow the proper procedures to ensure their safety (zero injury), the safety of the people around them as well as the safety of the location where they are. The equipment have to operate safely and when they fail, they fail safe, causing minimum damage to themselves and to their surroundings and if possible zero injuries to the workers around them. When safety issues are applied to the electrical field i.e. power systems, equipment and individuals dealing with such systems, a lot of interrelated factors come to play. The major factors can be classified into the safety features of the equipment or devices that are available during the following phases: manufacturing (or assembly), testing, operation & maintenance, the safety procedures that the workers have to follow under the same phases previously mentioned, the training level of the individuals dealing with each of the devices in the system and the acts & regulations that had to be complied with. The safety life cycle: 1) The inherited design safety features in the equipment and devices: these features are included to provide protection to the operator during his/her interaction with the equipment. Additional features can be included in the equipment but an extra cost. Their safety functions have to be weighed out against the additional cost. Certain features will be effective under certain conditions and others all the time. Such safety features have to be maintained by qualified personnel to render it functioning & effective. Certain features will be there for the operator to use when working with or close to the equipment to provide him/her with a safe place to work in. Some examples for such safety functions that are found in electrical equipment/systems: explosion proof enclosures of electrical motors (keep the arc inside the enclosure), metal clad designs (insulating the bus bars & partitioning the cubicles in a switchgear line-up) to better isolate the major components in the cell, using fire retardant/resisting, track resistant & low moisture absorbing (non-hygroscopic) insulating material & barriers, arc proof enclosures for switchgear (venting all the high pressure gases generated from internal arcing & short circuits through the chimney of the cell, keeping the other compartments in the faulted cell plus the other cells in-tact), in outdoor enclosures 2 doors are provided with panic bars, the GFI (ground fault interrupters) are used to protect human beings from ground currents (rather than protecting the equipment when standard molded case circuit breakers are used with electronic -solid state - or electromagnetic trips) in the ranges of 5 ma (function of duration of fault), pressure relief valves in transformer & other enclosures (to relief the built-up pressure inside the enclosure instead of rupturing the whole enclosure), the provision of grounding load or line bus (run backs) in switchgear after de-energizing the circuit (using the ground stirrups & grounding cables), the availability of fire extinguishers, work clearances (rather than electric clearance) are provided to facilitate maintenance & other work that will be performed later on site, the presence of electric interlocks & mechanical interlocks (Kirk key & provision for padlocks), the design of the battery room with ventilation opening as per the safety code recognized by the local inspection authority as well the equipment & other system's elements sizing (for normal operation, overload and fault conditions), equipment & system's elements protection against abnormal conditions and for certain installations (in hazardous and other designated locations - classified) the special requirements & additions/ modifications over & above the standard designs (like labeling

requirements, supplying specific information regarding the product in a specific format) have to be fulfilled as per the safety codes/acts/regulations that are adopted by the local authorities which are in charge of enforcing the safety issues. 2) Material handling: during the assembly process & until the equipment are shipped to the site and located on their bases, the handling of the components as well as the assembly has to be carried out according to logic, standards & safety policies. Safety hats, boots and maybe safety gloves are used and the operation of lifting devices (like fork lifts & cranes) are to be conducted by qualified personnel per the organization operation manual. 3) Safety during installation: site installation may include any of the following activities: cutting, welding, performing assembly tasks, poles erecting, guying & framing, raising equipment & installing them on poles/cross arms/ platforms, applying torque to bolts, crimping, laying, pulling, terminating & splicing cables. After the equipment have been built & shipped to the site, it has to be installed. The installation is carried out according to the supplier recommendations, safety governing bodies standards & safety policies of the organization. Personal protective & life saving equipment (depending on the installation) are used which may include foot protection, head protection, hearing protection, eye & face protection, respiratory protection, safety belts & safety nets. 4) Safety during site testing: site testing may include any of the following: racking in & out the circuit breaking & metering transformers, exercising the devices under tension (live) or off line, calibrating the meters & instruments, testing & setting the relays, testing by applying high voltage to certain elements of the installation. The energized portion of the installation has to be indicated very clearly to the individuals surrounding this test area. That area must be barricaded (surrounded by screens or with the appropriate post & tape). When certain devices are drawn out of their compartments, they must be clearly tagged to indicate that they are out for certain purpose (for example to isolate a certain area as work is in progress in such a zone). 5) Safety during operation: the safety instruction provided by the supplier of the equipment must be adhered to plus any other instructions included in the organization policy manual. For example, if a switch is being closed (to energize a circuit) the operator should not stand in front of the door of the cell having the switch, rather in front of the adjacent cell or if the policy indicates that all energization action should take place from a remote location, thus the operator should comply with such procedure. For safety reasons, all indicators (visual or audible) & alarms should be checked on a routine basis and verified for their proper functioning. Example for such indicators are: high/low pressure, high/low temperature, high/low current, high/low voltage, density, smoke detectors. 6) Safety during maintenance: maintenance can be classified broadly into either preventative or emergency (forced outage) maintenance. Maintenance may include any of the activities included in site testing plus the following activities: checking & verifying the devices in the system, downloading stored history data, replacing, repairing, washing & cleaning certain components. The safety measures to be taken can be similar to those observed during site testing like barricading, positioning of barriers & tagging plus others depending on the task at hand like the use of personal protection & life saving equipment for example rubber gloves (plus leather gloves worn on top of the rubber ones & rubber sleeves), safety belts, safety helmets, ..etc.. When working close to energized circuits, any of the following may be used to make the work area safe: rubber insulating line hose, rubber insulating insulator hoods, conductor covers,

insulator covers, crossarm covers, pole covers and rubber insulating blankets. All the major components (like rubber gloves for example) used to perform such critical tasks, as working close to energized circuits have to be tested before being used again. This will assure that the component will be free from any damage that may jeopardize the safety of the individual using it the next time. 7) The ongoing training on safety issues and the enforcement of such procedures: the individuals that have regular or infrequent contact with electrical equipment & devices have to be safety conscientious. The employer usually builds the sense of responsibility in all employees when it comes to safety issues (as done with productivity, efficiency & cost effectiveness issues). To achieve a high level of safety in the workplace, the employees are trained and their training has to be, practically, applied & put to use in their everyday activities. The area of training can be any of the following: the exercising, operation & maintenance of the electrical system components taking into consideration all the pertinent safety precautions, conducting themselves under emergencies like fires or natural disasters, handling hazardous materials in a safe manner, acquiring the necessary knowledge (relevant to their field of activity, existing systems & equipment) regarding the rules & regulations of the applicable occupational health & safety administration and related bodies having jurisdiction over the safety matters. 8) The inclusion or referencing of the appropriate sections & clauses of the regulations & acts pertaining to safety in the policy manual of the organization: the codes & manuals that are applicable to the safety of the workers are provided by the employer & are always accessible to the employees. The applicable standards are referenced in the organization policy manual. Examples for such acts, regulations, codes & standards are: Hazardous products act, Labour code, Controlled products regulations, Ingredient disclosure list, Workplace hazardous materials information system regulations, Electrical safety code & other safety-related standards provided by CSA, ANSI & other standards issuing bodies, the manuals provided by the occupational safety & health administration (eg. the record keeping, construction & technical manuals). The technical manual may include the following topics: general information, sampling, measurement methods & instruments, health hazards, safety hazards, construction operations, health care facilities, ergonomics, personal protective equipment, safety & health management. The topics contained in the construction resource manual are: inspections, citations & proposed penalties, recording & reporting occupational injuries & illness, construction work for general industry and safety & health regulations for construction which may contain the following subparts: general, general interpretation, general safety & health provisions, occupational health & environmental control, personal protective & life saving equipment, fire protection & prevention, signs, signals & barricades, materials handling, storage, use & disposal, hand & power tools, welding & cutting, electrical work, scaffolds, fall protection, cranes, hoists, elevators & conveyors, motor vehicles, mechanized equipment & marine operation, excavation, concrete & masonry, steel erection, tunnels, shafts & compressed air, demolition, blasting & use of explosives, power transmission & distribution, stairways & ladders, toxic & hazards substances. In the above manual, the subpart entitled power transmission & distribution may include the following relevant safety issues regarding the electrical power systems building/construction including associated equipment and other components: general requirements, tools & protective equipment, mechanical equipment, material handling, grounding for protection of crew members, overhead lines, underground lines, construction in energized substations, external load

helicopters, body belts & safety straps, aerial lifts, helicopters and definitions for terms used in above topics. Another example for a code that is used often with electrical system installations is the electrical safety code which contains a few section, tables & appendices. In general such codes are not meant to be design guides but rather to ensure a safe installation. The sections are: object, scope & definition, general rules, conductors, services & service equipment, circuit loading & demand factors, grounding & bonding, wiring methods, protection & control, class 1 & class 2 circuits, hazardous locations, flammable liquid, gas dispensing, service stations, garages, bulk storage plants, finishing processes & air craft hangers, locations in which corrosive liquids or vapours, or excessive moisture are likely to be present, patient care areas, installation of electrical equipment, motors & generators, installation of lighting equipment, fire alarm systems & fire pumps, signs & outline lighting, high voltage installations, elevators, escalators & similar equipment, electric cranes & hoists, electric welders, theatre installation, emergency systems, unit equipment & exit signs, motion picture studios, projection rooms & film exchanges, solar photovoltaic systems, diagnostic imaging installations, community antenna, radio & television installations, optical fiber cables, electrical communication systems, fixed electric space & surface heating systems, pools, tubs & spas, mobile home & recreational vehicle parks, airport installations, marinas, yacht clubs & fishing harbours, cathodic protection & the interconnection of electric power production sources. The safety chain: safety starts from the research stage in which a new product is being investigated & invented or an existing one is developed or modified all the way to the disposal of such product at time of replacement or elimination. 1) Research & development: during that phase of product development, the effects of the device failure on itself & surroundings are investigated as well as how it will affect the safety of individuals around it under normal conditions or during maintenance. 2) Specification step: when the specifications for the different equipment and components of a plant, substation or a distribution systems are written, the important design safety features required must be emphasized (beside the other clauses in the specification that cover other design details) and at time of production testing, the proof of the proper functioning of such safety devices/components must be furnished. 3) Design & assembly steps: at the design step the proper components that fulfill the end user requirement including all the safety functions stated in the specifications & related standards & codes must be included. At the time of assembly the workers have to adhere to the safety procedures applicable to the tasks at hand and complete the assembly per the design including for all the stated safety devices/components/functions in the drawings or bills of material. 4) Factory testing for component & assembly: the safety devices included in the assembled product must be checked, inspected or tested for proper operation. If testing includes the application of electrical voltage to the equipment, proper barricading should be provided when testing is in progress (screens or tapes). 5) Installation step: at this stage the safety procedures, rules & regulation for the construction site must be adhered to and fully complied with. 6) Site testing step: similar approaches to those taken with factory testing must be followed here. 7) Commissioning & start-up: at this stage all the equipment and devices are in place and connections are made. The supplier safety procedure must be followed when it comes to energizing (applying power to the different zones of the installation) to avoid any injury

incidents if for any reason a piece of equipment malfunctions. Extra cautious must be exercised as unexpected results may result that have to be handled according to the appropriate safety rules & regulations. 8) Operation: the organization procedures must be adhered to at all times, provided that they cover all known potential hazards, health and safety issues. 9) Maintenance: the maintenance steps for the different components of the system under the expected circumstances as included in the organization operation manual is to be followed. 10) Disposal: the operation manual must include a section that cover the proper handling including temporary storage, especially, for hazardous, flammable, combustible or dangerous (to the health under any possible condition) substances or equipment that contain such material.