In addition to carrying out installation and maintenance work on electrical equipment, electrical contractors in refineries have to perform their work in hazardous locations. The materials they deal with are potentially explosive, and electrical energy can set them off. As a result, refineries often require electrical contractors to have relevant certifications and special training to ensure they follow safe work practices to protect themselves and refinery employees from harm.
Type of Work
Refineries need electrical contractors to install, maintain and repair electrical systems. A refinery electrical system includes equipment for the supply of electricity, such as breakers, switches and transformers; motors for operating pumps, valves and fans; process heaters; and control equipment such as sensors, controllers, automation and control panels. Permits govern performance of the work on specific equipment in a particular area within a given time frame. The refinery administration ensures that the work area is safe for the electrical work during the time specified in the permit.
Tagging and Lockouts
When an electrical contractor works on a refinery's electrical system, he has to be certain that the equipment isn't under electrical power. Live wires in the work area, for instance, could represent a danger to the contractor, and electrical sparks might trigger an explosion. Tagging equipment with a "work in progress" notice lets other employees know that the contractor's working on it. Placing locks on breakers and switches to keep them in the open position ensures that other employees can't close circuits the contractor's working on.
Some areas of a refinery are inherently dangerous, with levels of explosive gases and chemicals potentially present at all times. Explosion-proof parts designed for use in such areas can withstand electric arcs and corresponding explosions inside their containers without setting off explosions of surrounding gases. For example, an explosion-proof connector inside an enclosure can withstand an internal explosion caused by a spark. Electrical contractors working on power equipment in these areas must ensure that the installed equipment is explosion proof and the tools and connectors they use are suitable for work in such areas.
For control equipment that doesn't need high levels of power, electrical contractors must check that parts are intrinsically safe if used in hazardous areas. Intrinsically safe parts use such low levels of voltage and electric power that the energy in their circuits isn't high enough to create a spark or set off an explosion. Before working with such equipment in areas that might contain dangerous gases, electrical contractors have to verify that parts are intrinsically safe or switch off and lock out their electric power.
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