On a commercial construction site, because most of the trades need electrical power to operate their hand tools, the electrical contractor must provide “temporary” electrical service throughout the site right after the concrete slab is poured.
While both the national and state electrical code (hereinafter “NEC”) require that the electrical contractor be licensed, that does not always mean that the person who holds the license is the same person who will be doing the actual installation of the temporary service on site, so it is difficult for the general contractor to insure that the temporary electrical, when installed, complies with the code.
Right after the concrete slab is poured that forms the “foot print” of the building, the electrical contractor puts up a temporary utility pole in close proximity to where the plans show the entrance will be. Then the electrical contractor runs a high voltage temporary power line into the building to a temporary electrical panel.
When the electrical panel is “powered up,” the municipal code official comes out and inspects the service, which includes the temporary electrical panel.
When the subcontractors come onto the site to do their work, they bring one-hundred long electrical cords and plug them into the electrical panel. The cords come in different colors so that the trades know which cord is theirs, so as not to pull out someone else’s cord and interrupt their work.
Often times, five or more trades are working in the same general area, all using power hand tools using long extension cords all plugged into the panel running across the floor. This situation creates a tripping hazard on site. To prevent this, OSHA requires that the cords be “bundled” together and moved out if the isle way.
Another hazard is created if the cords run too close to sharp objects such as steel beams or plumbing. This hazard is created because the contractor has not read, or does not understand how to read the plans and specifications showing where the steel beams or plumbing are placed. Yet another hazard can also result because the general contractor has not insured that the electrical contractor has not placed the temporary electrical line or panel where it was designed to be according to the plans.
Unfortunately, I have handled several cases wherein a worker has been seriously injured while just walking the site, but trips on a loose electrical cord, and also cases where a worker is holding a piece of metal, or a power tool, in his hands, and inadvertently comes into contact with a “live wire” which either had not been de-energized, or had been erroneously strung too close to the designated aisle way.
In order to protect yourself, make sure that you identify the code inspector’s inspection certificate and make sure you know the color codes for the power line and extension cords, which carry high “wattage” or “voltage” electricity. Be alert to be alive.