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It is noted that the article covers the installation of electrical equipment and wiring for elevators, dumbwaiters, escalators, moving walks, platform lifts and stairway chairlifts. This may include wiring for signals, communication with the car, lighting, heating, air-conditioning and ventilation of the car or hoistway for fire-detecting systems and pit sump pumps. In order to comply, the electrical system designer must determine the maximum available fault current at the elevator disconnecting means and assure the elevator disconnecting means overcurrent protective device will clear any overcurrent condition, up to the maximum available fault current, before any upstream overcurrent devices will operate. 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. Liquid-tight flexible nonmetallic conduit, Flexible cords and cables, or conductors grouped together and taped or corded, are permitted without raceway, where they are part of listed equipment, a driving machine or a driving-machine brake, Flexible metal conduit, liquid-tight flexible metal or nonmetallic conduit, 3/8 in. The Code provides guidance through regulations to establish requirements. 2. A second door is required if the equipment is rated over 1200 amps and over 6 ft. wide. However, it is likely that for many elevator controllers, this may not be high enough for the available fault current where they will eventually be installed. Good documentation is of key importance to recalling what decisions were made and why. A different occurrence involves exposure to the explosive blast when there is a line-to-line or line-to-ground arc blast. The branch circuit supplying these units is to be similarly dedicated, with the associated overcurrent device located in the machine room or similar location. Many people use portable generators until power is restored. above the pit floor, shall: Be weatherproof (NEMA 4). Notice the definition mentions the full range of operating times. If you specify a rescuvator, you must also specify a disconnect switch with an auxiliary contact that opens when the disconnect arm moves to the open position, but stays closed when the OCPD trips. It is mandatory, as in the car, that these items have a separate, dedicated branch circuit, and the required lighting is not to be supplied through a GFCI. The demand factor ranges from 1.00 for one elevator on a single feeder to 0.72 for 10 or more elevators on a single feeder. Therefore, there will be two signals to the elevator control panel related to smoke detectors: one from the designated floor smoke detector and another combined signal from the smoke detectors at the other lobby landings and in the equipment room. The architect has a choice of either traction or hydraulic elevators. It is worth mentioning that when 600 V is talked about as a limit in the NEC, it is generally meant that the familiar 600-V nominal-voltage system is considered to lie within the permitted zone, making it a common usage. Be sure to provide a horn/strobe alarm in large equipment rooms because they can be noisy, isolated places. Here again, the lighting is not to be connected to a GFCI, whereas such protection is required for the receptacle(s). This is especially true in an elevator shaft where measures have to be taken to ensure that a hazardous situation is not created. However, when I've put in elevators, NEC seems to always take a back seat to ANSI, which seems . It is of great importance that power to the various elevator functions can be quickly and reliably removed from the loads in case of emergency or for maintenance and troubleshooting. 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. 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. Based on the analysis, the arc-flash boundaries at the elevator/escalator controllers ranged from 3-16 in. Even though Edison grasped the basic ideas of fusing and overcurrent protection, many hazards remained. In case of emergency, electricians, maintenance personnel and any elevator technicians called in to the premises should have ready access to the key. As we have seen, a limited number of these are approved for elevator locations car, hoistway, pit and machine room. from the exposed components, and the incident energy calculated at 18 in. Traction elevators raise and lower the elevator cab with cables, a pulley system, and counter weights powered by a motor at the main drive wheel. This strategy works to improve the flexibility of the traveling cable, but it is contrary to a general NEC rule concerning the paralleling of conductors, which is generally done in very large sizes to avoid unwieldy wire pulls and terminations. 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. Apr 24, 2013. correct me if I'm wrong, but I believe it's damp. Use the below learning-reinforcement questions to study for the Continuing Education Assessment Exam available online at www.elevatorbooks.com or on page 111 of this issue. Name the principal code other than NEC that pertains to elevator design/installation. What is the definition of the machine room? Why are voltage limitations important? In which areas must live parts be enclosed? Why are feeder demand factors permitted for multiple elevators? Weight (passengers, freight, car and attendant machinery) may be fairly substantial, and speed is significant. In addition, requirements for selective coordination and shunt tripping should be complied with as needed for the installation. It is conditionally provided that fiber-optic cables and conductors for operating devices, operation and motion control, power, signaling, fire alarm, lighting, heating and air-conditioning circuits of 600 V or less are permitted to be run in the same traveling cable or raceway system. NEC specifies Hoistway wiring, and doesn't seem to distinguish between hoistway and pit. Follow the manufacturers instructions and precautions. Marking the available short-circuit (fault) current on the controller by the equipment installer. of the sprinkler heads. proved for elevator locations - car, hoistway, pit and a-chine roo equireents in Article odify the articles in Chap - ter For eaple, it is stated that the cross-sectional area 68 | WWW.ELEVATORWORLD.COM | June 2012 Continuing Education . 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. Finally, typical installations and compliance with all these requirements will be discussed. Hint: Duct Tape to the Rescue, NEC: Air Conditioning and Refrigerating Equipment Part 5. 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. 2.2.6.1 This switch shall be so located as to be acces-sible from the pit access door. The thinking behind this requirement is that the injured worker could have severe hand burns and be unable to operate a conventional doorknob. NEC 620.62 requires the elevator disconnecting means (fused switch or circuit breaker) to selectively coordinate with all supply-side overcurrent devices. +1-251-479-4514 | [emailprotected], Trkiye Office Louisiana State Uniform Construction Code Council adopts the 2014 NEC, Basic three-phase power measurements explained, Safety After the Storm Operating Portable Generators. tC|[S9G?+uJP>&/TOy o PK ! Flexible cords and cables in lengths not to exceed 6 ft. of a flame-retardant type and located to be protected from physical damage are permitted in machine rooms without being installed in a raceway. employees shall not perform any work on equipment where there is a potential to come in contact with energized mechanical or electrical hazards until all sources of energy have been de-energized, grounded or guarded.. Feeders may be installed within the hoistway where the elevator has a driving-machine motor in the hoistway or on the car or counterweight. Cylinders in hydraulic elevators usually aren't suitable for buildings taller than five stories. Have wiring identified for use in wet locations in accordance with the requirements in NFPA 70. The design engineer must identify the available fault current at the elevator controller to the installer so an elevator controller with adequate SCCR can be provided. Traction elevators are typically installed in a bank of elevators where fused switches, or circuit breakers in a panelboard are located in the machine room serving the bank of elevators. These may include: The author would like to recognize Jonathan Kennedy for his assistance in creating this article. It does specify wiring methods allowed, though, in 620. Part II of Article 620 concerns conductors used in elevator work, and several important requirements are covered. And so the needs can be very different. This device must be either a fused disconnect or a circuit breaker because ANSI/ASME A17.1 requires you to install an additional overcurrent protection device (OCPD) in the elevator equipment room. A raceway that comes loose on the inside of a hoistway could catch on a moving car, causing immense damage and hazard to users. GFCIs in elevator pits During an inspection of the elevators in a commercial building, the state inspector failed us for using a GFCI-type circuit breaker to protect a receptacle in the elevator pit. With the elevator car at the bottom landing, it is the length of cable as measured from the point of suspension in the hoistway to the bottom of the loop. Pits shall be maintained in a clean and dry condition. endstream endobj startxref This position paper is written to provide guidance to members whose employees are engaged in elevator-industry work that might expose them to arc-flash hazards, and to assist members in complying with applicable OSHA and National Fire Protection Association (NFPA) standards. First, the traveling cable must be composed of very fine-stranded conductors so it can flex with a minimum of internal stresses, ensuring long service life and reliability. +;-mka|7! endstream endobj 954 0 obj <. The elevator pit discharge system is not required to include an oil separator, except as required by section 1003.4. The fire loading resulting from an accumulation of abandoned low-voltage cabling may be considerable, and has to be understood and dealt with. The AHJ is saying that this is a violation of 620.23. Related Code Sections 802.1.8 Indirect/Special Waste, Elevator Pit Drain or Sump Pump The conduit alone can't act as the grounding means. The disconnecting means must disconnect the elevator from the emergency, standby and normal power systems. These are the individual branch circuits required for car lighting, receptacles, auxiliary lighting and ventilation on each elevator car; individual branch circuits for machine-room and similar location lighting and receptacle; and branch circuits for hoistway pit lighting and receptacle(s). Feeder and branch-circuit conductors are required to have specified ampacities: Feeder conductors of less ampacity are permitted for group installations and quite common in elevator work. These are part of Article 725, Class 1, Class 2 and Class 3 Remote-Control, Signaling, and Power-Limited Circuits. In this case, it may be best if the elevator controller manufacturer does not include the elevator disconnecting means (often offered as a circuit breaker) but instead have the installer provide a separate fused disconnect to comply with NEC 620.51(A) and also achieve a high SCCR for the elevator controller when fuses are provided as specified by the elevator controller and marked on the elevator controller nameplate. However, this can vary depending on building conditions and exterior grade. The fan should be on a dedicated circuit. The condition is that all conductors must be insulated for the maximum voltage applied to any conductor within the cables or raceway system, and all live parts of the equipment must be insulated from ground for this maximum voltage. A traditional elevator installation (which includes a machine room) requires access inside the elevator shaft. Home Articles Elevator World June 2012 Issue NEC Article 620: Elevators, Part 2. This is not the elevator companys responsibility. Examples of PPE that may be appropriate are non-conductive eye protection, clean leather or fire-resistant gloves, and natural-fiber or fire-resistant-rated long-sleeved shirts and pants, or fire-resistant-rated long-sleeved coveralls. Besides the initial determination requirement of paragraph (c) (1), the "host" employer must comply with the five (5) requirements of paragraph (c) (8) when engaging another employer (contractor) who will have employees in permit spaces under the control of the host employer. It is further stipulated that internal voltages of power-conversion equipment and functionally associated equipment, and the operating voltages of wiring interconnecting the equipment, are permitted to be higher, provided that the equipment and wiring are listed for the higher voltages. Indeed, most elevator accidents involve maintenance workers, yet even theirs is not an excessively dangerous profession. (e) Pit Maintenance. Doors must open in the direction of travel and be equipped with panic bars, pressure plates or other devices that are normally latched but open under simple pressure. Choose topics from a full list of courses covering electrical topics that cover what you need to know from the NEC and other electrical codes and standards. Elevator cab lights require emergency back-up power. Second, it must be configured so as to eliminate any chance of tangling or chafing against the inner surface of the hoistway or items mounted on it. Dont troubleshoot unless you can keep your shoe/boot soles dry. (All intentionally grounded elements must be held at equal potential.) There are options available to achieve this depending upon the customers needs. Car lighting, receptacles and ventilation 2. (Cross-sectional areas of conductors are given in Chapter 9, Tables 5 through 8. This is somewhat broader than A17.1-2007/B44-07. +91 8025357028, 2022 Elevator World, LLC. In Part One of this series (ELEVATOR WORLD, April 2012), we began an examination of National Electrical Code (NEC) 2011 mandates for elevators and related equipment installations. Fireman telephone jacks and telephone cabling are typically sufficient for each of these locations. If the entire feeder/branch circuit assembly were to be protected in the conventional manner, the motor would cut out long before reaching operating speed.