All Rights Reserved | Contact Us | Privacy Policy. NEC Article 620 Part VI, Disconnecting Means and Control, is rather exacting. This is because the material may contribute fuel to a fire that has originated elsewhere. Hydraulic elevators comprise a hydraulic reservoir, pump, cylinder, and controller. The elevator equipment room that serves a hydraulic elevator is almost always located on the lowest floor adjacent to the elevator shaft. 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. These circuit breaker selective coordination tables can be used to identify the maximum fault current that a pair of circuit breakers can selectively coordinate. 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. ASME A17.1 . Power for the elevator controller must first enter a lockable safety disconnect device, located adjacent to the door of the equipment room. A second door is required if the equipment is rated over 1200 amps and over 6 ft. wide. Part III, Wiring, looks at the types of wiring that may be installed in hoistways, cars, machine rooms and related spaces. GFI Receptacles: GFI receptacles shall be required in all elevator machine rooms, machinery spaces and elevator pit areas. 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). 6 feet, and shall meet the requirements of NEC 70 620.21(A)(1)(d). From the website: Mohawk Lifts offers car lifts and auto lifts for purchase, including 2 post lifts, 4 post lifts, storage lifts, heavy duty mobile column lifts, parallelogram lifts, and other specialty items. Part of the reason that elevator usage is extraordinarily safe is that construction and maintenance are regulated by the wonderfully robust ASME A17.1 2007/CSA B44-07 Safety Code for Elevators and Escalators, which contains overall construction and maintenance requirements everything from seismic mandates to machine-room lighting. 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. This is somewhat broader than A17.1-2007/B44-07. Freight Elevator Door Control: An Opportunity for Wireless Technology. 2. above the pit floor, shall: Be weatherproof (NEMA 4). This is important as the tradition of using only time-current curves for the analysis of overcurrent device operation is usually not sufficient since the time-current curves traditionally stop at 0.01 second (not time zero). For platform lifts and stairway chairlifts, the duty is intermittent. 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. 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. Fuses: Verify that the correct size, type and capacity are installed. Accordingly, the supply wires are protected only for short circuit, and the overload protection is provided closer to the motor. NEC 2011 also addresses branch circuits for machine room or control room/machinery space or control-space lighting and receptacles. You are a subscriber that needs to Sign In. 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. -inch conduit is needed to the sump pump. NEC Guidelines on Commercial Garages. The reason the NEC CMP 12 added these requirements, as shown in the panel statements, directly relates to the concern that elevator controllers can be installed in locations where the available fault current can be high and the inspector may not be able to clearly determine the SCCR of the elevator controller unless it is marked on the equipment. Please check your entries and try again. It is further stated that the disconnecting means are not to disconnect the branch circuits required in sections 620.22, 620.23 and 620.24. The next section, 620.36, concerns different systems in one raceway or traveling cable. The electrical system designer needs to communicate this information to the person responsible for specifying the elevator controller, which is most often the architect. 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. Pits shall be maintained in a clean and dry condition. Section 620.62, Selective Coordination, is central to multi-elevator installations and must be closely observed. !>x=yy Bvv8?~e PK ! f?3-]T2j),l0/%b This is especially true in an elevator shaft where measures have to be taken to ensure that a hazardous situation is not created. Thus, the traveling cable must be supported by a steel supporting member. You must locate this key switch at the main lobby or at the building fire command center. Based on the analysis, the arc-flash boundaries at the elevator/escalator controllers ranged from 3-16 in. When you're designing an electrical system for a building, don't let elevator requirements bring you down. These are: remote machine room and control room (for elevator and dumbwaiter), and remote machinery space and control space (for elevator and dumbwaiter). Hydraulic elevator installations are typically supplied from the main switchboard and have an elevator fused switch or circuit breaker in the machine room that serves as the elevator disconnect. The demand factors are given in Table 620.14, which allows significant reductions as the number of motors is increased. High-rise buildings pose additional concerns. Though I understand how someone might argue two. Provide continuous, non -slip, horizontal rungs every 12" for the full height of the pit ladder. All rights reserved. Finally, typical installations and compliance with all these requirements will be discussed. 836 Troy Schenectady Road ; Latham, NY 12110 . Mike Holt. 3. Additional requirements concern escape routes. Accordingly, for this application, the minimum size is reduced to 20 AWG for lighting circuits. To safeguard the passengers and electrical equipment, ASME A17.12.8.2.3.2 requires the power source to the elevator control panel to shut down prior to the discharge of water from a sprinkler head. Many undertake trips in these devices two or more times daily in full confidence that they will survive an uneventful experience with a minute chance of disaster or even inconvenience. Pit light with guard (ten foot candles min. Home Articles Elevator World April 2012 Issue NEC Article 620: Elevators, Part I. The same figure applies to nonmetallic wireways. The various items to consider and check when designing for elevator installations have many potential pitfalls. 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. Here again, the lighting is not to be connected to a GFCI, whereas such protection is required for the receptacle(s). Cylinders in hydraulic elevators usually aren't suitable for buildings taller than five stories. In contrast to the lighting, these receptacles must be connected to GFCI devices. 2023 Endeavor Business Media, LLC. Shi Liguang, Yao Lianghong, Luo Zhiqun and Wan Jianru, Constructional Stretch and Hoist-Rope Tension . To achieve flexibility and endurance, traveling cable is more finely stranded and, where possible, separated into discrete conductors. Part II of Article 620 concerns conductors used in elevator work, and several important requirements are covered. 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. 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.. We generally think of the 19th century as the great age of building codes. As always, the best advice in all instancesdo your homework, communicate often, and document decisions made. The locking capability is important so during maintenance, the equipment will not be inadvertently energized. It states an elevator is permitted to be run by an emergency or standby power system. The sum of the cross-sectional area of the individual conductors in raceways is not to exceed 40% of the interior cross-sectional area of the raceway, except as permitted for wireways. Because of this, several manufacturers offer an all-in-one shunt trip elevator disconnect switch that includes all the prewired accessories needed to comply with the various Code sections. The light switch shall be located so to be accessible from pit access door. Instruments: Use category III multimeters and be familiar with their use and limitations. Therefore, elevator equipment rooms must maintain a temperature between 50F and 90F. N _rels/.rels ( j0@QN/c[ILj]aGzsFu]U ^[x 1xpf#I)Y*Di")c$qU~31jH[{=E~ Upon loss of power, the rescuvator controls the cab, lowers it to the designated floor, and opens its doors. A single means for disconnecting all ungrounded main power-supply conductors is required and must be designed so no pole can be operated independently. Always verify all conditions and requirements with the state and the AHJ where the installation is taking place. 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. 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. 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. A single dedicated receptacle supplying a permanently installed sump pump does not have to be a GFCI type. As stated in Section 7 of the Elevator Industry Field Employees Safety Handbook: Unless it is not feasible, (i.e. Since 1953, Elevator World, Inc. has been the premier publisher for the global vertical transportation industry. 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. C.1.4 ELEVATOR PIT REQUIREMENTS 1. Utility-owned electrical structures not directly concerned with electrical generation, transmission and distribution are NEC regulated. 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. These must also be insulated for the maximum voltage applied to any conductor within the cable or raceway system. 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. Be sure to provide a horn/strobe alarm in large equipment rooms because they can be noisy, isolated places. 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. For instance, a typical elevator controller may traditionally have SCCR ratings from 5 to 10 kA. 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. Corporate Office 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 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. A separate branch circuit shall supply the hoistway pit lighting and receptacle (s). With heavy use on a hot day, the oil can overheat, causing elevator shutdown. First, you'll need to install lighting in the elevator equipment room (Photo 1) and shaft pit (Photo 2). The branch circuit is to be protected by an overcurrent device located in the machine room, control room/machinery space or control space. (B) Lighting Switch. 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. 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. Indeed, most elevator accidents involve maintenance workers, yet even theirs is not an excessively dangerous profession. Receptacle for pumps located in the pit shall be a single non-GFCI and shall be located 6 inches above the lowest landing. 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). The AHJ is saying that this is a violation of 620.23. Modern electronic elevator controls can be sensitive to temperature shifts. The Code provides guidance through regulations to establish requirements. Hint: Duct Tape to the Rescue, NEC: Air Conditioning and Refrigerating Equipment Part 5. Article 620s Definitions section includes two terms that describe spaces not attached to the outside of a hoistway. He also required GFCI protection for the hard-wired sump pump that did not require it. ) > 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 NEMA 4 : All electrical equipment, located less than 1225 mm (48 in.) 4.0 (2 Reviews) (2) CLAIMED . 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 code notes that elevator rails or other hoistway equipment are not to be used as the grounding conductor for lightning-protection systems. 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) Each fused switch or circuit breaker in the panelboard is used as an elevator disconnect. 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. It does specify wiring methods allowed, though, in 620. PK ! Many people use portable generators until power is restored. 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. Pit drainage must be designed to eliminate a minimum capacity of 3,000 gallons per hour (or 50 GPM) per elevator car. U.S. Latham, NY Shopping Miscellaneous Retail Stores, NEC Wheelchair lifts EazyLift Elevators, . For some manufacturers, such as Eaton, testing has been completed to determine the selective coordination ability of current-limiting BussmannTM series fuses with upstream Eaton circuit breakers. Mobile, AL 36606 USA The lighting switch shall be located so as to be readily accessible from the pit access door. 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. ), advise the building owner to correct the condition. This, however, can result in a dramatic increase in cost, space availability (lack thereof), and reduced efficiency. 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. Per the 2017 NEC, if the elevator is designated as an emergency system load, the disconnect must be protected by a surge protective device (SPD). Moreover, because motors have a higher starting current than other loads, the overcurrent protection protocol is unique to them and somewhat counterintuitive. ASME A17.1, Section 2.2.5, National Electrical Code, Rule 620-85 4. The article stands apart from the rest of the code in the sense it exempts these categories of circuits from the general requirements for wiring in most occupancies, found in Chapter 3. The disconnecting means must disconnect the elevator from the emergency, standby and normal power systems. In case of emergency, electricians, maintenance personnel and any elevator technicians called in to the premises should have ready access to the key. The code exempts some fairly broad areas where compliance is not expected. 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. 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. from components that are not otherwise guarded. These 29 CFR 1910.146 (c) (8) requirements are: Elevators with driving machines located on the car or counterweight, or in the hoistway are permitted outside the specified spaces. Section 620.43, Location of and Protection for Cables, provides that traveling cable supports are to be located so as to reduce the possibility of damage due to the cables coming in contact with the hoistway construction or equipment in the hoistway to a minimum. This switch will ensure that the elevator won't descend into the elevator pit and allow maintenance people to work safely in the area beneath the cab. The basic requirement is for minimum clear distances of various depths for equipment operating at 600 V or less, nominal, depending upon voltage to ground and lateral distance to insulated or grounded surfaces or exposed live parts (not an issue in elevator machine rooms). The disconnecting means is to be located adjacent to or an integral part of the motor controller. You need to Subscribe to continuing reading. For example, an inadequately supported ceiling fan could fall and cause injury or property damage. Flexible cords and cables, or conductors grouped together and taped or corded, are permitted to be installed without a raceway. Hydraulic elevators are typically more cost effective and used for buildings up to 5-6 stories. 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 faster and more energy efficient than hydraulic elevators, and are often used for high-rise buildings. 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. 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. Click to reveal [emailprotected] Use Underwriters Laboratories or Canadian Standards Association-labeled scopes tested for 1,000 V. Lockout/tagout: When troubleshooting is complete and further work can be accomplished without the equipment being energized, follow the lockout/tagout procedures in Section 7 of the. 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.. A different occurrence involves exposure to the explosive blast when there is a line-to-line or line-to-ground arc blast. This may be countered by providing good machine-room ventilation. Hydraulic reservoir characteristic of a hydraulic-piston-operated elevator. 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. 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. 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. 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. 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. Have wiring identified for use in wet locations in accordance with the requirements in NFPA 70. Each of these performs a different function, and the wiring mandates vary accordingly. However, when I've put in elevators, NEC seems to always take a back seat to ANSI, which seems . 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. Traditional wiring methods and materials come into play, as always, but it is necessary to rethink their deployment. 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. The sump pump/drain shall have the capacity to remove a minimum of 11.4 m. 3 /h (3,000 gal/h) per elevator. 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. All rights reserved. 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. The pump sends hydraulic fluid from the reservoir to the cylinder, buried deep below the elevator shaft. They are to be part of listed equipment, a driving machine or a driving-machine brake. Metallic articles: Remove metallic articles such as watches, chains, bracelets, earrings, belt buckles and keychains before troubleshooting. 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. The lighting is not to be connected to a GFCI, because the elevator car is not a place that should experience nuisance tripping. The main concern is to ensure that workers may escape to safety in the awful circumstance of an arc-fault event. 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. 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. It is worth noting that these NEC terms, used throughout Article 620, have been chosen to correlate with A17.1-2007 usage. A traditional elevator installation (which includes a machine room) requires access inside the elevator shaft. Dec. 21, 2010. (ASME has a separate document, A18.1-2008 Safety Standard for Platform Lifts and Stairway Lifts). 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. 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 These may include: The author would like to recognize Jonathan Kennedy for his assistance in creating this article.

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