Finally, in 1897, the first National Electrical Code (NEC) appeared. An exception provides that liquid-tight flexible metal conduit or liquid-tight flexible nonmetallic conduit 3/8 in. 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. or larger is permitted to be installed in lengths in excess of 6 ft. Where motor-generators, machine motors or pumping-unit motors and valves are located adjacent to or underneath control equipment and provided with extra-length terminal leads not exceeding 6 ft. in length, such leads are permitted to be extended to connect directly to controller terminal studs without regard to carrying-capacity requirements. 2m9 `K]f*F gaR 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. Selective coordination is also required for multiple elevators per NEC 620.62. Section 620.62, Selective Coordination, is central to multi-elevator installations and must be closely observed. It is also essential that machine-room lighting be totally reliable and separate from the machinery supply to facilitate troubleshooting in the event of elevator problems. Within cars, these additional wiring methods are permitted: The following additional wiring methods are permitted on the car assembly in lengths not exceeding 6 ft.: Within machine rooms, these additional wiring methods are permitted: The following wiring methods are permitted on the counterweight assembly in lengths not to exceed 6 ft.: Having looked at NEC 2011 mandates for elevator and related equipment installations, we will cover wiring methods, overcurrent protection, grounding and other related NEC provisions in part two of this series , running in the April 2012 issue of ELEVATOR WORLD. 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. The Code provides guidance through regulations to establish requirements. With heavy use on a hot day, the oil can overheat, causing elevator shutdown. 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 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 circuit breaker selective coordination tables can be used to identify the maximum fault current that a pair of circuit breakers can selectively coordinate. NEC Article 0: Elevator art by David Herres Continued. A clean and dry elevator pit and machine/control room provided (ASME A17.1 Rule 2.1.2) Machine/control room meets manufacturer's requirement of preserving ambient temperature control and humidity (ASME A17.1 Rule 2.7.9) Elevator floor covering installed with appropriate smoke and flame spread (ASME A17.1 Rule 2.14.2) 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. +91 8025357028, 2022 Elevator World, LLC. These conductors may be covered with suitable shielding for telephone, audio, video or higher-frequency communications circuits. The next section, 620.36, concerns different systems in one raceway or traveling cable. NEC 620.62 requires the elevator disconnecting means (fused switch or circuit breaker) to selectively coordinate with all supply-side overcurrent devices. [emailprotected] Through numerous editions, the NEC has, to a great extent, mitigated the hazards accompanying widespread use of electricity, particularly with respect to elevator technology. 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. Auxilliary gutters are permitted in machine and control rooms between controllers, starters and similar apparatuses. In some cases, it may require a means to test the shunt trip operation or have one contact operate the shunt trip of more than one elevator. ), 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. Fluid pressure in the cylinder raises and lowers the elevator cab. Car lighting, receptacles and ventilation 2. Many new buildings are incorporating an elevator design that does not include an equipment room (sometimes called machine room-less elevators). Follow the manufacturers instructions and precautions. 6 Stop Switch in Pits There shall be installed in the pit of each elevator an ASME A17.1 CODE enclosed stop switch or switches meeting the requirements The following material is reprinted with permission from the American of 2.26.2.7 and 2.2.6.1 through 2.2.6.3. The new ADAAG guidelines now require that emergency power be available to elevators that have four or more stories of travel above or below the accessible floor [4.1.3(9)(1)]. The cord is to be a hard-usage, oil-resistant type not over 6 ft. in length. The usual scenario for electrical injury is shock when electrical current passes through the human body. 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. Elevator travel is far safer than an automobile trip, and the chance of experiencing disaster is on the order of being struck by lightning in ones own backyard. Both electric and nonelectric elevators are to comply with Article 250, the code article that covers grounding and bonding in general. 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. The demand factors are given in Table 620.14, which allows significant reductions as the number of motors is increased. A single means for disconnecting all ungrounded main power-supply conductors is required and must be designed so no pole can be operated independently. Design practices that are acceptable in some jurisdictions may not be in others. +90 (216) 348 4876, India Office Any other utilization equipment associated with the elevator Guarding: Where possible, install temporary guarding to protect from inadvertent contact. 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. 4.0 (2 Reviews) (2) CLAIMED . A raceway that comes loose on the inside of a hoistway could catch on a moving car, causing immense damage and hazard to users. 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. A separate 120VAC, 15A circuit is required for cab lighting and accessories, and it must have its own local disconnect and OCPD in the equipment room as well. 354 Morgan Ave. The architect has a choice of either traction or hydraulic elevators. You are a subscriber that needs to Sign In. (All intentionally grounded elements must be held at equal potential.) A section on branch circuits for car lighting, receptacles, ventilation, heating and air-conditioning contains a number of important provisions. from components that are not otherwise guarded. 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. In driving through commercialized suburban areas, you frequently see paralleled conductors for large retail grocers (where there is a heavy refrigeration load). You may go up to 600 V for power circuits supplying door-operator controllers and door motors, branch circuits and feeders to motor controllers, driving-machine motors, machine brakes and motor-generator sets. It is of great importance for the design engineer to communicate with their local authority having jurisdiction (AHJ) to determine fire alarm requirements for the respective elevator installation. It states an elevator is permitted to be run by an emergency or standby power system. In order to aid enforcement, the panel additionally required marking the available fault current at the elevator controller. ELECTRIC PASSENGER & FREIGHT ELEVATORS ASME A17.1 2004 Electric Elevator Checklist 2004 Multi-car.doc Page 4 of 44 Page Completed for cars : - Last Updated: 8/1/05 Car Enclosure Electric 2.14 - Hydraulic 3.14 A17.1 (A17.2) COMMENTS CARS 1-6 Operating Control Devices ADA Requirements NEMA 4 : All electrical equipment, located less than 1225 mm (48 in.) Many of these are for portable lighting.). +;-mka|7! 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. 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. It is also worth mentioning that the stated purpose of the NEC is the practical safeguarding of persons and property from hazards arising from the use of electricity. This equipment is restricted to that used in connection with the specific elevator, dumbwaiter, escalator, moving walk, platform lift or stairway chairlift. f?3-]T2j),l0/%b You must locate this key switch at the main lobby or at the building fire command center. 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. A second door is required if the equipment is rated over 1200 amps and over 6 ft. wide. 354 Morgan Ave. The circuit(s) for the lighting and receptacles must be dedicated to the elevator area only. These are: remote machine room and control room (for elevator and dumbwaiter), and remote machinery space and control space (for elevator and dumbwaiter). 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. The two primary hazards are fire and electric shock or arc flash, although there are others. Special conditions: Troubleshooting in wet, hot or cold conditions calls for extra caution. 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. 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. Thus, the traveling cable must be supported by a steel supporting member. Working spaces for electrical equipment that may have to be examined, adjusted, serviced or maintained is required in all occupancies in an earlier NEC section, 110.26(A). However, space is frequently limited within the shaft and as such many ancillary components (shunt trip circuit breakers, fused disconnects) may need to be located outside of the elevator shaft. As greater numbers of elevators are added, the likelihood of them all operating simultaneously decreases so that it is permissible to reduce the feeder ampacity. In addition, the shunt-trip voltage must also be monitored by the Fire Alarm System. Another important electrical system design consideration for supplying power to multiple elevators is NEC 620.62. Instruments: Use category III multimeters and be familiar with their use and limitations. Requirements for commercial garages per the National Electrical Code. Convenience receptacles and lighting for maintenance purposes are required at the base of the pit and, in some instances (elevator manufacturer dependent), at the top of the elevator shaft. While machine room-less designs have been commercially available for many years, their use may still be unknown to some AHJs. After such an event, it is important that the affected worker is able to escape the area and get to help. CLAIMED . A single dedicated receptacle supplying a permanently installed sump pump does not have to be a GFCI type. Traveling cables are to be supported by one of these means: Looping the cables around supports for unsupported lengths less than 100 ft. NEC Guidelines on Commercial Garages. 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. This website is using a security service to protect itself from online attacks. The conductors must be in their original sheaths or grouped together and taped or corded. NEC Article 620 Part IV, Installation of Conductors, contains key mandates for elevator wiring. Corporate Office 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. Weight (passengers, freight, car and attendant machinery) may be fairly substantial, and speed is significant. 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? Building codes were deemed necessary to protect the public against shoddy builders and outmoded construction techniques. 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. Additionally, duty on elevator and dumbwaiter motors is rated as intermittent, whereas duty on escalator and moving-walk motors is considered continuous. Feeders may be installed within the hoistway where the elevator has a driving-machine motor in the hoistway or on the car or counterweight. 1. GET YOUR CEUS TODAY, 1998-2021. hbbd```b``+3dL `Y[gw9`RLJO*A$w$@L`F*{|0 P The simplest option is to use a shunt trip circuit breaker in either the feeder supplying the elevator or the elevator disconnect. 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. It is important, where mandated, that there be no more than a single disconnecting means, so if emergency action is required, first responders will not be able to power down the equipment from one location. 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. 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. Where necessary, it is mandated that suitable guards be provided to protect the cables against damage. Always verify all conditions and requirements with the state and the AHJ where the installation is taking place. Here are 23 ways that both chapters and the national office can meet todays major challenge of making members feel valued, IAEIs Online Training allows you to learn at your own pace or live with an expert instructor, from the comfort of your laptop or PC. Something went wrong. 953 0 obj <> endobj The elevator equipment room that serves a hydraulic elevator is almost always located on the lowest floor adjacent to the elevator shaft. The locking capability is important so during maintenance, the equipment will not be inadvertently energized. 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. Utility-owned electrical structures not directly concerned with electrical generation, transmission and distribution are NEC regulated. In these installations, it is best to design the elevator controller so the elevator controller SCCR is adequate for the available fault current. . Part III, Wiring, looks at the types of wiring that may be installed in hoistways, cars, machine rooms and related spaces. They must be in enclosures with doors or removable panels that can be locked in the closed position. You need to Subscribe to continuing reading. Marking the available short-circuit (fault) current on the controller by the equipment installer. Cross-sectional areas of wireways are found by multiplying the two interior dimensions.) Elevators with driving machines located on the car or counterweight, or in the hoistway are permitted outside the specified spaces. The same figure applies to nonmetallic wireways. The vast majority of equipment serving the elevator is located within this room (i.e., elevator controller). Selective coordination is also required for multiple elevators per NEC 620.62. All rights reserved. Pits shall be maintained in a clean and dry condition. Traveling cables are to be approved for hazardous locations and must comply with the appropriate sections for each hazardous-location class that covers use of flexible cords. +91 8025357028, 2022 Elevator World, LLC. Hazards created by water, snow or condensation in the work area can cause slips, falls and accidental contact. The light switch shall be located so to be accessible from pit access door. Article 620s Definitions section includes two terms that describe spaces not attached to the outside of a hoistway. z, /|f\Z?6!Y_o]A PK ! Cloudflare Ray ID: 7a2fbe9ebd7e2fe8 Mainline disconnect: DO NOT OPEN THE MAINLINE DISCONNECT SWITCH COVER unless employees are authorized, properly trained and appropriate measures are taken commensurate with the higher risk of arc-flash hazards. The light switch for the equipment room must be adjacent to the entrance door on the latch side. Traditionally, the electrical system design engineer has given little attention to the elevator controller. Since 1953, Elevator World, Inc. has been the premier publisher for the global vertical transportation industry. As mentioned, traditional installations of a traction or hydraulic elevator include a separate machine room. We shall now take a look at the principle requirements of Article 620, with particular emphasis on wiring requirements for elevator shafts, machine rooms and cars. Described below are several work practices that may be used to reduce arc-flash hazards when working on energized equipment: 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. 2. 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. U.S. Latham, NY Shopping Miscellaneous Retail Stores, NEC Wheelchair lifts EazyLift Elevators, . 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. In all cases, the working space must permit at least a 90 opening of equipment doors or hinged panels. 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. Home Articles Elevator World June 2012 Issue NEC Article 620: Elevators, Part 2. A little more narrowly focused (yet of great consequence) is the ubiquitous NEC, which, in the National Fire Protection Association (NFPA)s venerable Handbook edition, devotes 18 double-column pages to electrical design and installation requirements for elevators, escalators and related equipment. It is further specified the machine-room lighting switch be located at the point of entry. 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. 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. 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). endstream endobj 954 0 obj <. While the definitions are straightforward, their deployment in real-life building projects involves enormous legal and moral implications, given the fact that we are carrying large numbers of people hundreds of feet above the earths surface on a daily basis. Metal grating shall be installed over the hole that sits flush with the pit floor. On existing or listed equipment, conductors are permitted to be grouped together and taped or corded without being installed in a raceway. above the pit floor, shall: Be weatherproof (NEMA 4). A few years later, in 1880, Werner von Siemens built the first electric elevator, setting the stage for a new industry that would change the world by making the practical use of tall buildings possible. They are to be part of listed equipment, a driving machine or a driving-machine brake. Sumps and sump pumps in pits, where provided, shall be covered. ) > word/_rels/document.xml.rels ( N0HC;qRN/W$#{1EM]ZY|vj5h),-g!`./V/KKFY4D#la&V#=$Q7|l/d#hS 7+IDZ!J 6KucD^s`+>=(3E ), advise the building owner to correct the condition. 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. A separate branch circuit shall supply the hoistway pit lighting and receptacle (s). Similar provisions are attached to elevator-car heating and air-conditioning disconnecting means, and to other utilization equipment. Notice the definition mentions the full range of operating times. Each fused switch or circuit breaker in the panelboard is used as an elevator disconnect. Mobile, AL 36606 USA Accordingly, the supply wires are protected only for short circuit, and the overload protection is provided closer to the motor. Article 511 provides the requirements for commercial garages areas used for the storage or repair of self-propelled vehicles that use combustibles (liquid or gas) for power. The idea is quite simple. Another location that requires a separate branch circuit for lighting and receptacle(s) is the hoistway pit. 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 hazards are external to the equipment enclosure since equipment SCCR testing and evaluation criteria for product standards are most often performed with the enclosure doors closed and latched, and the fault occurring external to the enclosure. These may include: The author would like to recognize Jonathan Kennedy for his assistance in creating this article. For this reason, the NEC provides for adequate working space around electrical equipment that may need to be serviced. +90 (216) 348 4876, India Office But by understanding how these items fit together and what purpose they serve, you can have a successful project. For example, wiring that is under exclusive utility control and has to do with the generation and distribution of electrical power is not NEC regulated. tC|[S9G?+uJP>&/TOy o PK ! The lighting switch shall be located so as to be readily accessible from the pit access door. 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. Marking the elevator controller short-circuit current rating (SCCR) by the elevator controller manufacturer. wide or the width of the equipment, whichever is greater.
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