373 Final – Electrical Systems What type of lamp has electrodes at each end and has its inside surface of the tube coated with fluorescent phosphors?
... [Show More] Fluorescent Lamp Bright, clear bluish light lamps that can add phosphors to outer envelopes. Has a 24,000hr life and has 50 lumens per watt Mercury Vapor Lamps This lamp has an iodine in an inner envelope to shift color and increase efficacy to 80 lumens per watt but life drops to 10000hrs Metal Halide Lamp This lamp has 110 lumens per watt, 24000 hour life, and color renditions that often suffers High Pressure Sodium Lamps This lamp has the highest ratings for lifetime and efficacy but produces a monochromatic yellow light Low Pressure Sodium Lamps A device, typically made from semiconductor material, that restricts the flow of current in a circuit to only one direction Diode A diode that is designed to emit light of a particular frequency when current is applied to it LED Also known as a light fixture Luminares Best angle for single fixtures, or small number of fixtures that takes careful account of orientation and distance Point Grid Method The light arriving at a surface is the sum of the light arriving from all of the sources Abney's Law Method most commonly used for offices and other commercial spaces that is based on the coefficient of utilization Zonal Cavity Method Optimum lighting is also known as? Equivalent Spherical Illuminance For transmitting high-frequency telephone, digital, or television signals. encloses an insulated conducting core Electromotive Force An electric current that changes direction at regular intervals Alternative current Uses three different circuits, each 120 degrees out of phase with the others Three Phase Alternative Current If indoors, must be installed in a fire-resistant vault. small size, long life, high overload capacity Oil Insulated Transformer Vault not usually required, needs a catch basin for all contained fluid Nonflammable Fluid Filled "less flammable", may be installed indoors without a vault. liquid confinement area required Liquid Insulated Transformer A method of connecting the windings on a three-phase transformer in which one end of all three windings is connected to a common neutral center point, forming a Y shape. It is also known as a star connection. Wye Connection Heavy conductor, usually in form of solid copper bar. used for collecting, carrying, and distributing large electric currents Bus or Busbar Smallest wire gauge, should be used for building wiring 14 AWG Steel conduit with thinner walls [Show Less]