Chat with AIExam 5: Trolley Busways
Describe the luminaires used in the manufacturing area.
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VerifiedThe luminaires used in the manufacturing area are industrial-type fluorescent luminaires. Each luminaire uses two F96T12/CW/VHO lamps rated at 215 watts each. However, the power losses in the ballasts increase this value to 450 volt-ampere per luminaire. The fluorescent ballasts used are all of the high power factor type with individual fusing provided in accordance with 368.17. The luminaires are also equipped with lead-lag adders, which cause the lamps to fire at different times. In other words, the current wave crest of one lamp occurs nearly one-half cycle before the second lamp receives the wave crest. This arrangement eliminates most of the stroboscopic effect that occurs if individual lamps are used or if the lead-lag system is not used.
How is a 4-wire rubber cord used with trolleys?
(101) VerifiedThe trolleys have six graphite bronze shoes. These shoes make contact with the busbars and provide a path that continues through the fuse cutout and receptacle to the heavy-duty, 4-wire rubber cord. This cord is used to attach the various portable tools such as electric drills, buffers, grinders, and other equipment to the busway system. The 4-wire rubber cord provides three conductors to operate the 3-phase portable tools used on the job. The fourth conductor (green in color) is used to ground the equipment. One end of the grounding conductor must be attached securely to the trolley, and the other end to the housing of the portable tool. The cord must be approved for heavy-duty usage and may be a type SJ containing 12 AWG conductors. The fuses in the trolley are rated at 20 amperes.
What advantages does a suspended lighting system have?
(67) VerifiedA lighting system composed of fixed outlets and a fixed conduit system is not easily adaptable to changing requirements. On the other hand, a system of luminaires suspended from a trolley system can be readily shifted from one location to another as desired. It is not necessary to take down or replace heavy conduit systems as would be required to change a fixed lighting outlet system. If extensive alterations or a major plant changeover requires the removal of the lighting trolley duct, the duct sections are completely reusable.
Messenger wires supporting the trolley lighting circuit are adjusted for tension by________ located at the ends of the runs.
(86) A lighting system composed of ________outlets and a________conduit system is not easily adaptable to changing requirements.
(80) The power supply from the panelboard is fed into a busway run through a________ _.
(82) The equipment attachment plugs used with the duct system are ________, which eliminates several problems when portable tools having three-phase motors are used.
(86) Commonly, 4-conductor type SJ rubber cords are used to connect various machines; the colors of the individual conductors of the cord are black, white, red, and________ .
(70) What shape are the standard segments used to construct trolley systems?
(82) The industrial trolley bus is a ________-ampere, enclosed busbar electrical system.
(98) The 50-ampere lighting circuits used in the trolley systems are approved by________ .
(83) The lighting trolley is available in 5-ft (1.5-m) and 10-ft (3-m) sections, which are joined by________ couplings.
(90) Luminaires are equipped with________ , which cause the lamps to fire at different times.
(85) The couplings joining lighting trolley sections make a________ connection, electrically and mechanically, between two duct sections and permit free passage of the trolleys along the duct runs.
(79) A ________section provides the means for removing or inserting trolleys. This section contains two hinged doors that open when a lever is raised.
(88) Bus drop safety springs are used to maintain the proper tension on the horizontal and vertical cord runs. These springs are available with 40-, 80-, and________ pound ratings.
(87) The only tool needed to join the industrial-type trolley duct is a________ .
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