In these installations, it is best to design the elevator controller so the elevator controller SCCR is adequate for the available fault current. The branch circuit is to be protected by an overcurrent device located in the machine room, control room/machinery space or control space. Hoistway door interlock wiring from the riser must be flame retardant and have insulation suitable for a temperature not less than 200C (392F), much higher than that required for most raceway or cable applications. 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. Both electric and nonelectric elevators are to comply with Article 250, the code article that covers grounding and bonding in general. Reinforcing NEC 110.3(B) and NEC 110.10 to require the elevator controller marked SCCR to be equal to or greater than the calculated and 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. Shi Liguang, Yao Lianghong, Luo Zhiqun and Wan Jianru, Constructional Stretch and Hoist-Rope Tension . EazyLift Elevators, Stairlifts, Wheelchair Lifts & Ramps. Moreover, it is necessary to consider future worker safety for an indefinite period. Elevator power disconnect (with utility feed marking) located in the machine room or other permitted location. Other codes and standards interact with the NEC, and it is necessary to see how they all work together in order to create safe and compliant elevator designs/installations. Related Code Sections 802.1.8 Indirect/Special Waste, Elevator Pit Drain or Sump Pump Conductors supplying more than one motor, motor controller or power transformer are to have an ampacity not less than the sum of the nameplate current ratings of the equipment plus all other connected loads. Acceptable types of wire for this application are given in Table 400.4, which occurs in an earlier chapter and lists various types of elevator cable for lighting and control in both unclassified and hazardous locations. Fireman telephone jacks and telephone cabling are typically sufficient for each of these locations. hb``` ea``j~p2nfH
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0B.":9.@, e`xI;=7O3fvbb8:SC;%O*20] Next, with multiple elevator banks, the controller will usually allow only one elevator at a time to operate, reducing the amount of emergency power required. Hazards created by water, snow or condensation in the work area can cause slips, falls and accidental contact. They are to be located so as to be protected from physical damage, are to be of a flame-retardant type, and must be part of listed equipment, a driving machine or a driving-machine brake. Notwithstanding, if sprinklers are installed in hoistways, machine rooms or the like, the disconnecting means is permitted to automatically open the power supply to the affected elevator(s) prior to the application of water. Hint: Duct Tape to the Rescue, NEC: Air Conditioning and Refrigerating Equipment Part 5. Mobile, AL 36606 USA These circuit breaker selective coordination tables can be used to identify the maximum fault current that a pair of circuit breakers can selectively coordinate. 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. A second door is required if the equipment is rated over 1200 amps and over 6 ft. wide. The elevator rails, like the ground system of the entire building electrical structure, are to be bonded to the lightning-system ground electrode so these all remain at the same potential even during a lightning event, ensuring side flash does not occur. or larger, not exceeding 6 ft. in length, are permitted between control panels and machine motors, machine brakes, motor-generator sets, disconnecting means and pumping motors and valves. (A) tells us that the lighting and receptacle (s) for the pit must be on separate circuits. Hydraulic reservoir characteristic of a hydraulic-piston-operated elevator. The demand factors are given in Table 620.14, which allows significant reductions as the number of motors is increased. Selective coordination is also required for multiple elevators per NEC 620.62. NEC Article 620 Part VI, Disconnecting Means and Control, is rather exacting. . Some elevator controller manufacturers believe this is an issue for the electrical system designer and installer to address and remedy by adding impedance to the system for lowering the available fault current. 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. Heating and air-conditioning equipment located on the car must not be in excess of 600 V. All live parts of electrical apparatuses are to be enclosed to protect workers and the public against accidental contact. With the new elevator controller requirements, more attention will be focused on the elevator system. For instance, one method to reduce the available fault current is to add an isolation transformer ahead of the elevator controller. For this reason, the NEC provides for adequate working space around electrical equipment that may need to be serviced. This equipment is restricted to that used in connection with the specific elevator, dumbwaiter, escalator, moving walk, platform lift or stairway chairlift. 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. Each of these performs a different function, and the wiring mandates vary accordingly. 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. NEC Article 620 Part IV, Installation of Conductors, contains key mandates for elevator wiring. With heavy use on a hot day, the oil can overheat, causing elevator shutdown. Section 725.45 concerns the location of overcurrent devices and provides for feeder and branch-circuit taps, transformer primary side overcurrent device location and overcurrent device location at the input side of electronic power sources. 354 Morgan Ave. In a time when increasing value is placed on even small amounts of real estate, elevator design must strive to configure, efficiently control and drive elements to whatever degree possible, and that is the thinking behind some alternate locations for these structures. Elevator power disconnect (with utility feed marking) located in the machine room or other permitted location David Herres David Herres holds a New Hampshire Master Electrician's license and has worked as an electrician in the northern part of that state for many years. 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. The thinking behind this requirement is that the injured worker could have severe hand burns and be unable to operate a conventional doorknob. The traveling cable, of necessity, is exempted. The various items to consider and check when designing for elevator installations have many potential pitfalls. Additionally, ampacities of the individual conductors and flame-retardant properties of the overall cable are important factors. Similarly, underground wiring in mines is not NEC regulated, although other, non-mine wiring below ground (such as lighting in an underground traffic tunnel) is covered. Besides the power-supply disconnect discussed, it is provided that elevators have a single means for disconnecting all ungrounded car lights, receptacles and ventilation power-supply conductors for that elevator car. Even though Edison grasped the basic ideas of fusing and overcurrent protection, many hazards remained. (C) Duplex Receptacle. Modern electronic elevator controls can be sensitive to temperature shifts. Please check your entries and try again. from components that are not otherwise guarded. Nevertheless, the primary NEC focus is on elevators, and the intention is to mitigate the hazards associated with the use of electricity. (f) Illumination of Pits. Pit light with guard (ten foot candles min. If your specifications require a vent at the top of the shaft for venting smoke, you must provide a key switch with a pilot light to control that vent. You can email the site owner to let them know you were blocked. 2m9 `K]f*F gaR
Though I understand how someone might argue two. ), a duplex 15A 120-volt receptacle in pit with ground- fault circuit protection and a 15A 120-volt Non GFCI receptacle for the sump pump. Metallic articles: Remove metallic articles such as watches, chains, bracelets, earrings, belt buckles and keychains before troubleshooting. Thus, the need for door interlock functionality is recognized. +1-251-479-4514 | [emailprotected], Trkiye Office This accomplishes two functions. Generally, it is decreed that the supply voltage is not to exceed 300 V between conductors (allowing for the familiar 240-V concept), although there are exceptions. In addition, requirements for selective coordination and shunt tripping should be complied with as needed for the installation. 4.0 (2 Reviews) (2) CLAIMED . And as the designer, you can become the fulcrum on which all of these requirements and authorities exert their leverage, but an understanding of elevator basics can help you handle the pressure. The disconnecting means is to be located adjacent to or an integral part of the motor controller. The light switch for the equipment room must be adjacent to the entrance door on the latch side. The Uniform Building Code requires two-way communications between the central command center and the elevators, each elevator lobby, emergency power rooms, and by entries into enclosed stairways (Section 403.5.3). It provides that where more than one driving-machine disconnecting means is supplied by a single feeder, the overcurrent protective devices in each disconnecting means are to be selectively coordinated with any other supply side overcurrent protective devices. z!0: - [Content_Types].xml ( n0EUb*>-RxV=QUAl"93dFk%Y?l}MGDV Electricity is often one of the initial services to fail during a storm. 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. The same figure applies to nonmetallic wireways. Hydraulic elevators comprise a hydraulic reservoir, pump, cylinder, and controller. Traditionally, the electrical system design engineer has given little attention to the elevator controller. You need to Subscribe to continuing reading. The two main types of elevators are hydraulic and traction. First, the ATS signals the elevators that it's about to switch over to emergency power preferably 30 sec or more prior to switching, which allows the elevator controller to bring each elevator cab to the nearest landing and stop, thus protecting the motors and electrical system. This is somewhat broader than A17.1-2007/B44-07. 988 0 obj
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This clear working space must be 30 in. 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. Part III, Wiring, looks at the types of wiring that may be installed in hoistways, cars, machine rooms and related spaces. Car lighting, receptacles and ventilation 2. If the building has emergency power available, use it to supply the cab lights. 3. He is saying that each pit requires a separate circuit, in other words "dedicated". 354 Morgan Ave. ASME A17.1, Section 2.2.5, National Electrical Code, Rule 620-85 4. Hoistway pit lighting and receptacles 5. Something went wrong. Here again, the lighting is not to be connected to a GFCI, whereas such protection is required for the receptacle(s). [emailprotected] The basic rule for conductor fill of a metal wireway, as given in Article 376, is that the sum of the cross-sectional areas of all contained conductors at a cross section of a wireway is not to exceed 20% of the interior cross-sectional area of the wireway. Apr 24, 2013. correct me if I'm wrong, but I believe it's damp. +91 8025357028, 2022 Elevator World, LLC. Freight Elevator Door Control: An Opportunity for Wireless Technology. The simplest option is to use a shunt trip circuit breaker in either the feeder supplying the elevator or the elevator disconnect. One. This may be countered by providing good machine-room ventilation. The drain or sump pump discharge shall be into the sanitary or storm drainage system through an indirect waste connection. For current-limiting fuses, the information to achieve selective coordination has been available for many years in fuse amp ratio tabular form. 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. +;-mka|7! All Rights Reserved | Contact Us | Privacy Policy. tC|[S9G?+uJP>&/TOy o PK ! If we fast forward more than 36 centuries, we see some important new developments in elevator technology. NEC 70620.85 Smoke detectors to recall elevators on Phase I recall are required to be located on each landing, A traction elevator's equipment room is typically located at the top of the building, directly over or adjacent to the shaft. APPENDIX A 2.2. All equipment in a machine room-less design is installed within the elevator shaft or exterior compartment near the elevator shaft, including the elevator controller and the elevator disconnecting means. Accordingly, for this application, the minimum size is reduced to 20 AWG for lighting circuits. The feeder OCPD needs to remain closed so the remaining elevators have power and continue to function. NEC Article 620 covers elevators, dumbwaiters, escalators, moving walks, platform lifts and stairway chairlifts. Something went wrong. Traction elevators are typically faster and more energy efficient than hydraulic elevators, and are often used for high-rise buildings. 68 | WWW.ELEVATORWORLD.COM | June 2012 Continuing Education . endstream
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. It is important for design engineers to communicate this with the architect and owner during the design phase, as it will impact space needs elsewhere in the facility to accommodate electrical equipment. Regardless of the number of elevators, only one smoke detector is required at each floor lobby, but it must be located within 21 ft of every elevator door. It employs specialists in Mobile, Alabama, and has technical and news correspondents around the world. After such an event, it is important that the affected worker is able to escape the area and get to help. We have circuited the receptacles and lights in the pits to the same circuit. 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. As recommended in NFPA 70E, the National Elevator Industry, Inc. (NEII) commissioned an arc-flash hazard analysis (in compliance with IEEE Standard 1584-2002 for procedures for calculating the incident energy of the arc flash) by an independent consultant to determine at what level an arc-flash hazard exists to employees who work on energized elevator equipment. 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. This requirement applies to all controllers, disconnecting means and other electrical equipment that may need servicing, inspection or maintenance. The branch circuit supplying these units is to be similarly dedicated, with the associated overcurrent device located in the machine room or similar location. The Americans with Disabilities Act Accessibility Guidelines for Buildings and Facilities (ADAAG) now require the cab to have a special phone accessible by individuals with disabilities. Be sure to provide a horn/strobe alarm in large equipment rooms because they can be noisy, isolated places. Sign up for our free e-newsletter. All Rights Reserved | Contact Us | Privacy Policy. You are a subscriber that needs to Sign In. No provision is to be made to automatically restore power. Years may lapse between the design and installation stages of a project. Also located in this room might be, but not limited to: exhaust fan, cooling unit (depending on local requirements and/or requirements set forth by the individual elevator supplier), lighting, voice and/or data drop serving the elevator cab emergency phone, elevator controller primary fused disconnect, elevator feeder shunt-trip circuit (i.e., shunt-trip circuit breaker), elevator cab lighting fused switch, and convenience receptacle(s). 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 disconnecting means is to be an externally enclosed, operable, fused motor circuit switch or circuit breaker capable of being locked in the open position. See Section 3 of the. The pump sends hydraulic fluid from the reservoir to the cylinder, buried deep below the elevator shaft. Such cable groups are to be supported at intervals not over 3 ft. and located so as to be protected from physical damage. By subscribing, you agree to our User Agreement and Privacy Policy & Cookie Statement. The elevator equipment room that serves a hydraulic elevator is almost always located on the lowest floor adjacent to the elevator shaft. By subscribing, you agree to our User Agreement and Privacy Policy & Cookie Statement. 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. U.S. Latham, NY Shopping Miscellaneous Retail Stores, NEC Wheelchair lifts EazyLift Elevators, . Utility-owned electrical structures not directly concerned with electrical generation, transmission and distribution are NEC regulated. Metal grating shall be installed over the hole that sits flush with the pit floor. 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. Part IX, Grounding, states that metal raceways, Type MC cable, Type MI cable or Type AC cable attached to elevator cars are to be bonded to metal parts of the car bonded to the equipment grounding conductor. Similar provisions are attached to elevator-car heating and air-conditioning disconnecting means, and to other utilization equipment. Such vehicles include, but are not . 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. These may include: The author would like to recognize Jonathan Kennedy for his assistance in creating this article. First, you'll need to install lighting in the elevator equipment room (Photo 1) and shaft pit (Photo 2). Additional branch circuits are to supply other utilization equipment not covered above. Selective coordination is defined by the NEC as: Localization of an overcurrent condition to restrict outages to the circuit or equipment affected, accomplished by the selection and installation of overcurrent protective devices and their ratings or settings for the full range of available overcurrents, from overload to the maximum available fault current, and for the full range of overcurrent protective device opening times associated with those overcurrents.. First, it is now clear that elevator controllers must be marked by the manufacturer with their SCCR. The lighting switch shall be located so as to be readily accessible from the pit access door. Many of these are for portable lighting.). It need not be exactly centered on the equipment, and working spaces of adjacent pieces of equipment may overlap. On existing or listed equipment, conductors are permitted to be grouped together and taped or corded without being installed in a raceway. Beginning with Article 320, Armored Cable (Type AC) and concluding with Article 398, Open Wiring on Insulators, each code-sanctioned cable and raceway is treated, ranging from the familiar Type NM (trade name Romex) to the exotic Integrated Gas Spacer Cable (Type IGS). Because they need to move and flex, traveling cables are not required to be in a raceway. 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. But the lights don't have to be in the pit itself. When you're designing an electrical system for a building, don't let elevator requirements bring you down. The AHJ is saying that this is a violation of 620.23. 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. Where a feeder powers more than one elevator, you need selective coordination; the OCPDs must be series-designed so a fault at one of the elevators will be cleared by only the OCPD serving it. Overcurrent devices protecting these branch circuits are to be located in the machine room or similar location. Other terms defined in NEC Article 620 are Control System, Motion Controller, Motor Controller, Operation Controller, Operating Device and Signal Device.
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