| Home | Fire
Safety | Skyscrapers Home Emergencies | Glossary |
|
Electrical construction drawings show the layout and design of an electrical installation. A complete set of construction drawings and specifications of the building electrical system is needed to convey design information to the contractor. The following construction drawings and details are generally required: 1. Complete plans and specifications of all electrical work 2. Labeling criteria of all electrical equipment 3. Lighting floor plan(s) including electrical circuits indicating conduit and wiring sizes 4. Power floor plans including electrical circuits indicating conduit and wiring sizes, equipment, and disconnect switches 5. Exit sign/means of egress lighting location and power supply 6. Panelboard schedule 7. Lighting fixture schedule 8. Symbol schedule and diagrams Specifications and drawings should include requirements for: 1. Raceway and conduit with fittings 2. Wire and cable 3. Electrical boxes, fittings, and installation 4. Electrical connections 5. Electrical wiring devices 6. Circuit and motor disconnects 7. Hangers and supporting devices 8. Electrical identification 9. Service entrance and details 10. Overcurrent protection 11. Switchboards 12. Grounding 13 Transformers 14. Panelboards 15. Motor control centers 16. Lighting fixtures Symbols are used on construction drawings to represent lighting and power distribution components and equipment. Fig.1 shows commonly used symbols. No specific symbol set is universally accepted by the industry. The symbols provided are typically modified by the engineering consulting firm and used on their drawings. Many manufacturing companies have their own set that may be distinctly different than the symbols provided. For example, the symbol SD may mean a door-controlled switch but might denote a dimmer switch on another set of drawings. The legend of symbols is an important part of the construction drawings. It should always be reviewed to ascertain the meaning of an electrical symbol on a specific drawing. Symbols are arranged on the drawings in the form of a one-line diagram. One line represents the conductors extending between two symbols, regardless of the number of conductors. Generally, the single line without any additional identification indicates a two-wire set of conductors-either an ungrounded (hot) and grounded conductor or two ungrounded conductors. A single line with three slashes indicates a three-wire set of conductors and so on. Fig.1 Common electrical abbreviations, acronyms, and symbols. Symbols will vary with set of drawings. Prev: Electrical
Codes, Licenses, and Permits |