The disconnecting means is also to be a listed device. These selective coordination tables for current-limiting fuses show the minimum amp ratio required between a pair of fuses of a given type(s) to achieve selective coordination. (Hard-service and junior hard-service are trade names that apply to over 30 types of flexible cord, all beginning with the letter S. They have varying properties, such as oil resistance, and various material compositions for insulation, such as a thermoplastic elastomer. Any other utilization equipment associated with the elevator Traditionally, the electrical system design engineer has given little attention to the elevator controller. The basic idea is that there must be a separate, dedicated circuit for car lights, receptacles and ventilation on each car. (To design and install an elevator for a Class I, Division 1 location would be quite an undertaking.). Otherwise, specify that the elevator supplier provide a battery back-up unit to power the lights in the event of an outage. He has focused on writing since 2006, having written for such magazines as ELEVATOR WORLD, Electrical Construction and Maintenance, Cabling Business, Electrical Business, Nuts and Volts, PV Magazine, Electrical Connection, Solar Connection, Solar Industry Magazine, Fine Homebuilding Magazine and Engineering News. Indeed, most elevator accidents involve maintenance workers, yet even theirs is not an excessively dangerous profession. Elevators with driving machines located on the car or counterweight, or in the hoistway are permitted outside the specified spaces. David Herres holds a New Hampshire Master Electricians license and has worked as an electrician in the northern part of that state for many years. All rights reserved. Part X, Emergency and Standby Power Systems, is simple and straightforward. Special conditions: Troubleshooting in wet, hot or cold conditions calls for extra caution. In these installations, it is best to design the elevator controller so the elevator controller SCCR is adequate for the available fault current. The elevator pit discharge system is not required to include an oil separator, except as required by section 1003.4. With heavy use on a hot day, the oil can overheat, causing elevator shutdown. For just $7.99 per month, you can gain access to more than 5,000 articles from all Elevator World Publications, this includes EW Global, EW Europe, EW India, EW Middle East, EW Turkey, and EW UK. As an installer and an inspector, one common issue I've seeen is incompatible connections associated with raceways connections and fittings. Other terms defined in NEC Article 620 are Control System, Motion Controller, Motor Controller, Operation Controller, Operating Device and Signal Device. The same figure applies to nonmetallic wireways. Fireman telephone jacks and telephone cabling are typically sufficient for each of these locations. See Section 3 of the. After reading this article, you should have learned: Which locations require sepa-rate, dedicated branch circuits Which branch circuits are not to be provided with ground fault circuit interrupter (GFCI) pro-tection Which locations must have one or more duplex receptacles Where overcurrent protection for hoistway, pit and machine-room lighting must be located How unsupported lengths of traveling cables are measured. Pit light with guard (ten foot candles min. To avoid this situation, designers can specify elevator controls with a safety feature commonly called a rescuvator. The floor specified as the designated landing, which must be approved by the Fire Marshal, is usually the floor on grade level so passengers can quickly exit to the outside. Part VIII, Machine Rooms, Control Rooms, Machinery Spaces, and Control Spaces, states elevator and similar-installation driving machines, motor-generator sets, motor controllers and disconnecting means are to be installed in a room or space set aside for that purpose. Granle is a licensed professional engineer with Sebesta Blomberg & Associates, Rochester, Minn. https://www.facebook.com/ElectricalConstructionMaintenanceMagazine, https://www.linkedin.com/company/electrical-construction-maintenance/, ABCs Construction Backlog Indicator Down to Start 2023, The Most Popular Code Quizzes of the Week from 2021, The 10 Most Popular Photo Galleries of 2021, Whats Wrong Here? The two primary hazards are fire and electric shock or arc flash, although there are others. -inch conduit is needed to the sump pump. Firefighters can then use portable telephone handsets in combination with the jacks and cabling. It begins by considering metal and nonmetallic wireways. But, building codes had been in existence for many centuries. Provide continuous, non -slip, horizontal rungs every 12" for the full height of the pit ladder. The usual scenario for electrical injury is shock when electrical current passes through the human body. U.S. Latham, NY Shopping Miscellaneous Retail Stores, NEC Wheelchair lifts EazyLift Elevators, . David Herres An example would be the elevator, as well as all wiring in a utility-owned administration building. %%EOF If the smoke detector at the designated landing goes into alarm, the elevator will stop at a predetermined alternate floor, which is usually the floor above the designated floor. It is further stressed that no provision is to be made to open or close the disconnecting means from any other part of the premises. In addition, requirements for selective coordination and shunt tripping should be complied with as needed for the installation. Marking the available short-circuit (fault) current on the controller by the equipment installer. Many people use portable generators until power is restored. Modern electronic elevator controls can be sensitive to temperature shifts. For all of this to come together in the real world, there had to be some assurance that these new technologies could be used safely on a wide scale. Conductors supplying a single power transformer are to have an ampacity not less than the nameplate current rating of the power transformer plus all other connected loads. In such cases, it's economically justifiable to specify a traction type elevator. This clear working space must be 30 in. The cover shall be secured and level with the pit floor. By subscribing, you agree to our User Agreement and Privacy Policy & Cookie Statement. The traveling cable, moreover, may be run without raceway from inside the hoistway to elevator-controller enclosures and to the elevator car and machine room and similar locations outside the hoistway for a distance not exceeding 6 ft. Overload protection for motors is to conform with Article 430, Part III, the general code area that covers motor and branch-circuit overload protection for all motors. The branch circuit is to be protected by an overcurrent device located in the machine room, control room/machinery space or control space. CLAIMED . Even non-composite fiber-optic cable, which does not carry electrical energy, is subject to the code. It is further specified the machine-room lighting switch be located at the point of entry. Be sure to provide a horn/strobe alarm in large equipment rooms because they can be noisy, isolated places. On existing or listed equipment, conductors are permitted to be grouped together and taped or corded without being installed in a raceway. For example, it is stated that the cross-sectional area of the individual conductors in a wireway are not to exceed 50% of the interior cross-sectional area of the wireway. Other building loads, such as power and lighting, may function as the energy absorbing means, provided these loads are automatically connected to the emergency or standby power system operating the elevators and large enough to absorb the regenerative power. Machine room-less elevator installations incorporate the elevator controller and often the primary disconnecting means in a convenient package that is located within the elevator shaft. Power for the elevator controller must first enter a lockable safety disconnect device, located adjacent to the door of the equipment room. The cord is to be a hard-usage, oil-resistant type not over 6 ft. in length. : inspecting; troubleshooting; observing; etc.) It is important for the design engineer to coordinate with the architect to determine the elevator manufacturer basis of design to determine if and when additional power and lighting is required. As for height, the working space must extend from the grade, floor or platform to 6-1/2 ft. or the height of the equipment, whichever is greater. The main concern is to ensure that workers may escape to safety in the awful circumstance of an arc-fault event. NEC 620.62 requires the elevator disconnecting means (fused switch or circuit breaker) to selectively coordinate with all supply-side overcurrent devices. (Cross-sectional areas of conductors are given in Chapter 9, Tables 5 through 8. Many professionals believe the NEC is applicable only for voltages over a certain level, but that is not the case. (ASME has a separate document, A18.1-2008 Safety Standard for Platform Lifts and Stairway Lifts). from the exposed components, and the incident energy calculated at 18 in. The disconnecting means must disconnect the elevator from the emergency, standby and normal power systems. Receptacle for pumps located in the pit shall be a single non-GFCI and shall be located 6 inches above the lowest landing. The elevator controller manufacturer must determine the required elevator controller SCCR as stated in the elevator controller specification and provide an elevator controller SCCR that is equal to or greater than the available fault current thats indicated in the design documents where there are multiple elevator controllers at different locations. Similarly, the integrity of the traveling cable is emphasized. All of these options and special wiring can be challenging depending upon the location of the shunt trip circuit breaker as well as who has responsibility for providing these additional options. Bonding of elevator rails to a lightning-protection system grounding conductor is permitted, but the conductor itself is not to be located in the hoistway. The main impetus for the creation of the NEC in the closing years of the 19th century was the collective anguish experienced by insurance underwriters who were losing vast amounts of money due to liability and physical damage claims resulting from Edisons electrification of, first, Lower Manhattan and then the world. These may include: The author would like to recognize Jonathan Kennedy for his assistance in creating this article. +1-251-479-4514 | [emailprotected], Trkiye Office If elevators are supplied by the emergency, legally required standby or critical operation power systems, then selective coordination is required per the 2017 NEC in 700.32, 701.27 or 708.54. GFI Receptacles: GFI receptacles shall be required in all elevator machine rooms, machinery spaces and elevator pit areas. The light switch shall be located so to be accessible from pit access door. Conductors supplying a single motor are to have an ampacity not less than the percentage of motor nameplate current determined from Section 430.22(A) and (E). Pit drainage must be designed to eliminate a minimum capacity of 3,000 gallons per hour (or 50 GPM) per elevator car. (All intentionally grounded elements must be held at equal potential.)