Common Work Results for Electrical

NOTE This standard is the umbrella for the electrical discipline. It states once the code basis and the administrative and execution provisions that every electrical standard on the project inherits, so that the equipment, wiring, lighting, communications, and electronic safety and security standards can confine themselves to their own products and procedures. (1.1)

NOTE This standard carries no product requirements. The products and procedures below are governed by their own standards, and nothing here restates them. (1.4)

NOTE Where an electrical standard cites an article of NFPA 70, the citation refers to that article as it reads in the edition adopted under Adopted Electrical CodeAdopted Electrical CodeParameterEach project supplies its own value.adopted-electrical-code, and the number is given for the reader's convenience rather than as a pin to a particular edition. (3.3)

NOTE Many jurisdictions adopt NFPA 70 one or two cycles behind the current publication, several enforce a state electrical code built on it, and nearly all enact amendments. The electrical code is a fact about the project, answered once, and every electrical standard reads the same answer; the design was prepared against that edition, and a newer edition is not a substitute for it. (3.9)

NOTE Marked-up prints cost the least to produce and record what the field crew actually saw, and they live on paper and resist searching. Revised CAD files put the record in the Owner's drafting standard at the price of a redrafting step in which field marks are reinterpreted. A revised model carries the most information and feeds facility management software directly, and it is realistic where the project was coordinated in a model to begin with. (4.4.3)

NOTE The additional qualifications a particular system requires of its installers, such as the fire alarm, structured cabling, and medium-voltage cable splicing certifications, are stated by the standards governing those systems. (5.1.3)

NOTE An equipment listing is what the inspector and the Engineer of Record rely on in place of evaluating each product's electrical and fire safety themselves, and NFPA 70 110.3(B) makes the listing instructions part of the installation requirements. A field modification that alters the wiring, the overcurrent devices, or the enclosure voids the listing, and the field evaluation label restores the basis the Authority Having Jurisdiction accepts. (5.2.3)

NOTE Construction power, lighting, and the protection of temporary circuits are governed by Temporary Facilities And ControlsTemporary Facilities and ControlsResolves to the current adopted revision.sync/temporary-facilities-and-controls. (5.3.4)

NOTE Type 1 keeps fingers off live parts in a dry, conditioned interior and does nothing else. Type 12 is gasketed against dust and dripping oil and does not resist a hose. Type 3R sheds rain and sleet outdoors and admits a hose stream, condensation, and wind-driven dust. Type 4 resists the hose, and Type 4X resists the hose and the atmosphere, in stainless steel where it will be struck and in a non-metallic material where chlorides would pit the steel. Type 7 contains an internal explosion of a Class I gas, and Type 9 excludes a Class II dust and limits its own surface temperature; the device inside either has to be listed for the location along with the box. Each product standard asks the enclosure question once for the location its product normally occupies, and these clauses raise the answer wherever the location is worse. (6.9)

NOTE Conduit is the most flexible element in a ceiling and is routed last under the space priority rule the mechanical umbrella sets, which is why a separate electrical coordination process is wasted effort where a composite one exists. The elements the electrical trade cannot move are the equipment and its working space, the busway, and the cable tray, and those are what the coordination drawing exists to protect. (7.1.6)

NOTE The design of dedicated electrical rooms, including their clearances, headroom, ventilation, and egress, is governed by Electrical RoomsElectrical RoomsResolves to the current adopted revision.sync/electrical-rooms; this section applies to electrical equipment wherever else it is installed, including mechanical rooms, corridors, ceiling spaces, and the outdoors. (8.6)

NOTE Equipment is bought from a schedule and circuits are sized from the same schedule, and the two diverge the moment a substitute unit arrives with a larger motor or a different control transformer. The mechanical and process umbrellas require the equipment trade to reconcile the approved unit against the circuit shown; this clause puts the same check on the electrical side, so that a breaker is corrected while it is still a line item instead of a change order. (9.8)

NOTE A firestop system is listed for a specific annulus around a specific penetrant, and a sleeve cut to fit the conduit bundle with no room for the fill is the most common reason an electrical penetration fails inspection. Setting the sleeve to a listing before it is cast is what makes the firestop installable later. (10.10)

NOTE This standard sets no restraint detail of its own. It names the threshold once so that no electrical standard can be read as exempt from it, and it leaves the exemptions, the design responsibility, the bracing, and the certification to the restraint standard, which carries them in full. (11.4)

NOTE A short notice period and daytime outages suit a building that is unoccupied or whose occupants can tolerate an interruption, and they keep the work on straight time. Outages outside working hours protect an occupied office, school, or clinic and are paid for in overtime and in a crew that works at night; a hospital, a data center, or a plant on continuous process tolerates neither rule and reviews each outage on its own, which is the position with no standing rule. Two weeks of notice gives an Owner time to warn tenants and reschedule operations, and one or two days is enough where the Owner's own staff are the only people affected. (12.1.4)

NOTE Blowing an enclosure out with compressed air drives conductive dust into bus joints, relays, and trip units and leaves it there, which is why vacuum cleaning is required. Gear stored in a damp building without its heaters energized condenses moisture on its insulators, and the first evidence of it is an insulation resistance reading that fails acceptance. (13.9)

NOTE A small building with a few panelboards and a lighting control system is covered in an hour or two, and a plant with switchgear, generators, transfer switches, and a power monitoring system can need days; the hours are set by what the Owner's staff will be expected to operate without calling the Contractor back. The hours stated here carry the systems whose standards state none, and a system standard that states its own hours adds to them. (14.5)

NOTE The warranty term and coverage particular to a product are stated by the standard governing that product, and the notice, response, correction, and claim procedure for every warranty is administered under Warranties And BondsWarranties and BondsResolves to the current adopted revision.sync/warranties-and-bonds. (15.7)

NOTE A one-year warranty from substantial completion is the term the industry's standard general conditions carry, and most projects adopt it without discussion. Longer terms are bought by institutional owners who keep their buildings for decades, at a premium that rises with the term, because the contractor is pricing equipment failures it does not control. (15.8)