ranged from 0.06 cal/cm2 to 0.95 cal/cm2, which indicates that the arc-flash hazard to employees is primarily to the hands and arms. Shi Liguang, Yao Lianghong, Luo Zhiqun and Wan Jianru, Constructional Stretch and Hoist-Rope Tension . The proposals resulted in adding new requirements in the 2017 NEC for: Marking the elevator controller short-circuit current rating (SCCR) by the elevator control-ler manufacturer. All rights reserved. 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). . A second door is required if the equipment is rated over 1200 amps and over 6 ft. wide. These are part of Article 725, Class 1, Class 2 and Class 3 Remote-Control, Signaling, and Power-Limited Circuits. Flexible cords and cables part of listed equipment operating at 30 V (42 VDC) or less, similarly supported and protected, jacketed and flame retardant, are permitted. In addition, requirements for selective coordination and shunt tripping should be complied with as needed for the installation. And so the needs can be very different. Where multiple driving machines are connected to a single elevator, there is to be one disconnecting means to disconnect the motor(s) and control-valve-operating magnets. Pits shall be maintained in a clean and dry condition. 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. If a smoke detector goes into alarm, it signals the elevator to go into Fire Recall Function, at which point the controller directs the elevator cab to travel to its pre-programmed designated landing, open its doors, and remain stopped there until the alarm clears. 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. Many professionals believe the NEC is applicable only for voltages over a certain level, but that is not the case. 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. The AHJ is saying that this is a violation of 620.23. 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. 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. These requirements, found in Article 620 (part of Chapter 6, Special Equipment), are in addition to NEC Chapters 1-3, which stipulate general wiring protocols applicable in most residential, commercial and industrial venues. In all cases, the working space must permit at least a 90 opening of equipment doors or hinged panels. Please check your entries and try again. As mentioned, traditional installations of a traction or hydraulic elevator include a separate machine room. Elevators with driving machines located on the car or counterweight, or in the hoistway are permitted outside the specified spaces. For instance, a typical elevator controller may traditionally have SCCR ratings from 5 to 10 kA. The next section, 620.36, concerns different systems in one raceway or traveling cable. %%EOF Hard-service cords and junior hard-service cords are permitted as flexible connections between the fixed wiring on the car and devices on the car doors or gates. Required lighting shall not be connected to the load side of a ground-fault circuit interrupter. NEMA 4 : All electrical equipment, located less than 1225 mm (48 in.) Many NEC articles address voltage limitations, and Article 620 is no exception. The NEC rule specifies that the minimum size for paralleled conductors is 1/0 AWG, which is much too big for an elevator traveling cable. In contrast to the lighting, these receptacles must be connected to GFCI devices. !>x=yy Bvv8?~e PK ! In fact, an entire elevator system for a project is most often designed and specified by the architect who has little understanding of the electrical distribution system. Where voltages exceed 600, a sign reading DANGER HIGH VOLTAGE is required. Such cable groups are to be supported at intervals not over 3 ft. and located so as to be protected from physical damage. If you provide your elevators with emergency power, you must run communications wires between the automatic transfer switch (ATS) and the elevator control panel. ASME A17.1 . Get more of Elevator World. In case of emergency, electricians, maintenance personnel and any elevator technicians called in to the premises should have ready access to the key. The electrical energy does not traverse the human body, but proximity to the explosion means severe injury is possible from the intense heat and concussive shockwave. NEC 620.62 requires the elevator disconnecting means (fused switch or circuit breaker) to selectively coordinate with all supply-side overcurrent devices. CLAIMED . GFI Receptacles: GFI receptacles shall be required in all elevator machine rooms, machinery spaces and elevator pit areas. Proper selective coordination in a multi-elevator installation on the same feeder ensures if one elevator develops a fault, the other units will not be shut down. You are a subscriber that needs to Sign In. 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. N _rels/.rels ( j0@QN/c[ILj]aGzsFu]U ^[x 1xpf#I)Y*Di")c$qU~31jH[{=E~ It is worth noting that these NEC terms, used throughout Article 620, have been chosen to correlate with A17.1-2007 usage. 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. 2.2.6.1 This switch shall be so located as to be acces-sible from the pit access door. 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. By subscribing, you agree to our User Agreement and Privacy Policy & Cookie Statement. If a hydraulic elevator loses power because a heat detector goes off or for any other reason it could trap occupants for an unpleasant amount of time. He is saying that each pit requires a separate circuit, in other words "dedicated". 2.2.2.6 . 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. 953 0 obj <> endobj 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. The main concern is to ensure that workers may escape to safety in the awful circumstance of an arc-fault event. This is not the elevator companys responsibility. Flexible cords and cables (same conditions as within hoistways). The 12 definitions provided in NEC 2011, Section 620.2 are the place to start for guidance in this area, and the sections that follow lay out implementation guidelines that are very relevant in todays environment. You must run a separate insulated grounding conductor with the feeder conductors from the electrical source to the elevator controller. The locking capability is important so during maintenance, the equipment will not be inadvertently energized. Additionally, duty on elevator and dumbwaiter motors is rated as intermittent, whereas duty on escalator and moving-walk motors is considered continuous. A single means for disconnecting all ungrounded main power-supply conductors is required and must be designed so no pole can be operated independently. Article 620 follows this pattern by opening, in Section I, General, with a statement of scope and definitions applicable to the topic under consideration. 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). This is somewhat broader than A17.1-2007/B44-07. %PDF-1.5 % Accordingly, the supply wires are protected only for short circuit, and the overload protection is provided closer to the motor. After such an event, it is important that the affected worker is able to escape the area and get to help. Part III, Wiring, looks at the types of wiring that may be installed in hoistways, cars, machine rooms and related spaces. The usual scenario for electrical injury is shock when electrical current passes through the human body. NEC 2011 also addresses branch circuits for machine room or control room/machinery space or control-space lighting and receptacles. NEC Guidelines on Commercial Garages. This clear working space must be 30 in. 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. 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. 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. The panel further clarified that the marked SCCR value must be adequate for the available fault current to ensure a safe installation. Hard-service cords are permitted only as flexible connections for the top-of-car operating device or the car-top work light. The Code provides guidance through regulations to establish requirements. (f) Illumination of Pits. 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. NEC articles generally adhere to a template, which greatly aids in navigating and quickly locating mandates as needed for project design or, on an installation level, in the field. The action you just performed triggered the security solution. Fireman telephone jacks and telephone cabling are typically sufficient for each of these locations. NEC Article 0: Elevator art by David Herres Continued. It employs specialists in Mobile, Alabama, and has technical and news correspondents around the world. For elevators with battery lowering systems, an additional contact must be supplied and wired to disable the battery lowering system when the elevator disconnect is manually operated for maintenance. In an elevator machine room, where space may be limited in the first place, the working-space mandate must be factored in very early in the design process lest an unthinkable amount of rework be necessary. The many codes and guidelines that regulate the electrical design of an elevator can seem overwhelming, and dealing with the electrical inspector, elevator inspector, and Fire Marshal can be even more intimidating. Section 620.85, GFCI Protection for Personnel, provides that 125-V, single-phase, 15- and 20-amp receptacles installed in pits, hoistways, machinery spaces, machine rooms, escalators and moving walks, and on elevator car tops are to be GFCIs. 974 0 obj <>/Filter/FlateDecode/ID[<64E135C225F1064D91BC8119D14516A9>]/Index[953 36]/Info 952 0 R/Length 105/Prev 204101/Root 954 0 R/Size 989/Type/XRef/W[1 3 1]>>stream Home Articles Elevator World April 2012 Issue NEC Article 620: Elevators, Part I. As such, elevator controller manufacturers should make the effort to rethink their designs to avoid costly system design changes. 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. IAEI News Magazine. +90 (216) 348 4876, India Office Similarly, motor branch-circuit short circuit and ground-fault protection must be as required in Article 430, Part IV, for all motors. Every building is different. It is important to note, that these selective coordination tables can indicate a lack of selective coordination at a given fault current for circuit breakers that do not show overlap on the time-current curves of the circuit breakers. Cables used in Class 2 power-limited circuits are permitted between risers and signal equipment and operating devices, provided they are supported and protected from physical damage and are of the jacketed and flame-retardant type. Three wiring categories within hoistways are allowed in addition, each with exceptions. U.S. Latham, NY Shopping Miscellaneous Retail Stores, NEC Wheelchair lifts EazyLift Elevators, . A section on branch circuits for car lighting, receptacles, ventilation, heating and air-conditioning contains a number of important provisions. The conduit alone can't act as the grounding means. A surge of immigration to the U.S., the end of slavery and, on both sides of the Atlantic Ocean, a burgeoning industrial revolution ignited an acceleration in new building. There are options available to achieve this depending upon the customers needs. Section 620.37 re-emphasizes that only wiring used in connection with the elevator is permitted within the hoistway, machine room, control room/machinery space or control space. 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. Hint: Duct Tape to the Rescue, NEC: Air Conditioning and Refrigerating Equipment Part 5. Firefighters can then use portable telephone handsets in combination with the jacks and cabling. Feeders may be installed within the hoistway where the elevator has a driving-machine motor in the hoistway or on the car or counterweight. Metallic articles: Remove metallic articles such as watches, chains, bracelets, earrings, belt buckles and keychains before troubleshooting. . 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). This, however, can result in a dramatic increase in cost, space availability (lack thereof), and reduced efficiency. Loss of voltage to the control circuit for the disconnecting means shall cause a supervisory signal to be indicated at the control unit and required remote annunciation. Overcurrent devices protecting these branch circuits are to be located in the machine room or similar location. 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.
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