Dont troubleshoot unless you can keep your shoe/boot soles dry. 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. When you're designing an electrical system for a building, don't let elevator requirements bring you down. Hammurabi, sixth king of Babylon and creator of the Babylonian Empire, decreed: If a builder builds a house for someone and does not construct it properly, and the house which he built falls in and kills its owner, then that builder shall be put to death. (Hard-service and junior hard-service are trade names that apply to over 30 types of flexible cord, all beginning with the letter S. They have varying properties, such as oil resistance, and various material compositions for insulation, such as a thermoplastic elastomer. 2m9 `K]f*F gaR Hydraulic reservoir characteristic of a hydraulic-piston-operated elevator. Hard-service cords are permitted only as flexible connections for the top-of-car operating device or the car-top work light. endstream endobj 954 0 obj <. If the disconnecting means is an integral part of the motor controller, it is to be operable without requiring opening of the enclosure. 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. Even though Edison grasped the basic ideas of fusing and overcurrent protection, many hazards remained. Traction elevators are typically faster and more energy efficient than hydraulic elevators, and are often used for high-rise buildings. Mike Holt. Additional branch circuits are to supply other utilization equipment not covered above. 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. 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. 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). 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. As we have seen, a limited number of these are approved for elevator locations car, hoistway, pit and machine room. The branch circuit is to be protected by an overcurrent device located in the machine room, control room/machinery space or control space. Machine room/control space lighting and receptacles 4. Many of these are for portable lighting.). Part VII, Overcurrent Protection, divides this topic into four categories for elevators and similar equipment, depending upon the nature of the specific equipment: For operating devices and control and signaling circuits, protection against overcurrent is in accordance with the requirements of Sections 725.43 and 725.45. Part X, Emergency and Standby Power Systems, is simple and straightforward. ) > 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 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. ASME A17.1, Section 2.2.5, National Electrical Code, Rule 620-85 4. Hint: Duct Tape to the Rescue, NEC: Air Conditioning and Refrigerating Equipment Part 5. The usual scenario for electrical injury is shock when electrical current passes through the human body. 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. 354 Morgan Ave. 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. With heavy use on a hot day, the oil can overheat, causing elevator shutdown. NEC 620.62 requires the elevator disconnecting means (fused switch or circuit breaker) to selectively coordinate with all supply-side overcurrent devices. 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. It is further specified the machine-room lighting switch be located at the point of entry. Sumps and sump pumps in pits, where provided, shall be covered. Click to reveal Elevators with driving machines located on the car or counterweight, or in the hoistway are permitted outside the specified spaces. The fan should be on a dedicated circuit. A raceway that comes loose on the inside of a hoistway could catch on a moving car, causing immense damage and hazard to users. Below is a summary of these new 2017 NEC sections: In order to comply with these requirements a chain of events must occur. He is saying that each pit requires a separate circuit, in other words "dedicated". 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. The feeder OCPD needs to remain closed so the remaining elevators have power and continue to function. Both electric and nonelectric elevators are to comply with Article 250, the code article that covers grounding and bonding in general. The light switch shall be located so to be accessible from pit access door. The main concern is to ensure that workers may escape to safety in the awful circumstance of an arc-fault event. You are seeing this message for one of three reasons: You have reached your limit of free content. Other terms defined in NEC Article 620 are Control System, Motion Controller, Motor Controller, Operation Controller, Operating Device and Signal Device. or larger, not over 6 ft. in length. If you can illuminate the pit using lights that are "above the top of the pit" (whatever that . Other requirements: Spa's and Hot Tubs 1996 NEC 15-20 Amp 120 volt Receptacle Requirements for Dwelling units: All outdoor For elevators that regenerate power back into a power source unable to absorb the regenerative power under overhauling elevator load conditions, a means to absorb this power is to be provided. When the elevator car is at the top landing, it is the length of cable as measured from the point of suspension on the car to the bottom of the loop. There are several actions that could trigger this block including submitting a certain word or phrase, a SQL command or malformed data. Section 620.62, Selective Coordination, is central to multi-elevator installations and must be closely observed. NFPA 72 requires the control circuit between the Fire Alarm System and the shunt trip be monitored for integrity. 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. Society of Mechanical Engineers. Elevator motors are inherently intermittent duty. The drain or sump pump discharge shall be into the sanitary or storm drainage system through an indirect waste connection. Flexible cords and cables (same conditions as within hoistways). The simplest option is to use a shunt trip circuit breaker in either the feeder supplying the elevator or the elevator disconnect. 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. 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. 2.2.2.6 . 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). If the equipment must remain energized to perform work, effective insulation and safe electrical working practices should be observed. Marking the elevator controller short-circuit current rating (SCCR) by the elevator controller manufacturer. The code exempts some fairly broad areas where compliance is not expected. This is especially true in an elevator shaft where measures have to be taken to ensure that a hazardous situation is not created. 6 feet, and shall meet the requirements of NEC 70 620.21(A)(1)(d). You are a subscriber that needs to Sign In. 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. 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. +;-mka|7! 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. GFI Receptacles: GFI receptacles shall be required in all elevator machine rooms, machinery spaces and elevator pit areas. These are covered for generic, non-elevator specific use in earlier articles, 376 and 378, in Chapter 3, Wiring Methods and Materials. hb``` ea``j~p2nfH 'xXg00,/(_ Iq8PDdg-~ s$!XI;Fn0vu `h`R 1y 0B.":9.@, e`xI;=7O3fvbb8:SC;%O*20] The traveling cable, of necessity, is exempted. 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.. 1. 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. 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. (A) tells us that the lighting and receptacle (s) for the pit must be on separate circuits. These conductors may be covered with suitable shielding for telephone, audio, video or higher-frequency communications circuits. Requirements in Article 620 modify the articles in Chapter 3. 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. A section on branch circuits for car lighting, receptacles, ventilation, heating and air-conditioning contains a number of important provisions. It need not be exactly centered on the equipment, and working spaces of adjacent pieces of equipment may overlap. The elevator equipment room that serves a hydraulic elevator is almost always located on the lowest floor adjacent to the elevator shaft. 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. 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. Be sure to provide a horn/strobe alarm in large equipment rooms because they can be noisy, isolated places. Guarding: Where possible, install temporary guarding to protect from inadvertent contact. All Rights Reserved | Contact Us | Privacy Policy. (g) Stop Switch in Pits. My reasoning comes from 620.24 (A) and (C). The code notes that elevator rails or other hoistway equipment are not to be used as the grounding conductor for lightning-protection systems. 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? PK ! We generally think of the 19th century as the great age of building codes. This lighting and receptacle circuit is separate from the circuit serving the motor. Pits shall be maintained in a clean and dry condition. The surest means of avoiding an arc-flash hazard is to lockout and tagout the electrical service to a controller. 23.254.250.15 The architect has a choice of either traction or hydraulic elevators. Required lighting shall not be connected to the load side of a ground-fault circuit interrupter. The demand factors are given in Table 620.14, which allows significant reductions as the number of motors is increased. 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? In such cases, it's economically justifiable to specify a traction type elevator. With these new NEC requirements, there is now the potential that an elevator controller SCCR may be required thats higher than what elevator manufacturers have historically furnished. 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. 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. (Cross-sectional areas of conductors are given in Chapter 9, Tables 5 through 8. We resume with a look at wiring methods, overcurrent protection, grounding and other NEC provisions as they relate to these installations. For example, it is stated that the cross-sectional area of the individual conductors in a wireway are not to exceed 50% of the interior cross-sectional area of the wireway. Thus, the need for door interlock functionality is recognized. The cover shall be secured and level with the pit floor. 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 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. Article 620s Definitions section includes two terms that describe spaces not attached to the outside of a hoistway. The two documents are in harmony and should be used in conjunction. 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. After reading this article, you should have learned: Which locations require sepa-rate, dedicated branch circuits Which branch circuits are not to be provided with ground fault circuit interrupter (GFCI) pro-tection Which locations must have one or more duplex receptacles Where overcurrent protection for hoistway, pit and machine-room lighting must be located How unsupported lengths of traveling cables are measured. Fireman telephone jacks and telephone cabling are typically sufficient for each of these locations. ), advise the building owner to correct the condition. 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. There are options available to achieve this depending upon the customers needs. 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. The same figure applies to nonmetallic wireways. Receptacle for pumps located in the pit shall be a single non-GFCI and shall be located 6 inches above the lowest landing. By subscribing, you agree to our User Agreement and Privacy Policy & Cookie Statement. 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. Thus, the traveling cable must be supported by a steel supporting member. Sign up for our free e-newsletter. Get directions, reviews and information for Eazylift Albany LLC in Latham, NY. A different occurrence involves exposure to the explosive blast when there is a line-to-line or line-to-ground arc blast. 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. Flexible cords and cables, or conductors grouped together and taped or corded, are permitted to be installed without a raceway. Mobile, AL 36606 USA Traveling cables are to be supported by one of these means: Looping the cables around supports for unsupported lengths less than 100 ft. Part III, Wiring, looks at the types of wiring that may be installed in hoistways, cars, machine rooms and related spaces. 354 Morgan Ave. Performance & security by Cloudflare. 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) It does specify wiring methods allowed, though, in 620. As an installer and an inspector, one common issue I've seeen is incompatible connections associated with raceways connections and fittings. 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. 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.. You must run a separate insulated grounding conductor with the feeder conductors from the electrical source to the elevator controller. First, you'll need to install lighting in the elevator equipment room (Photo 1) and shaft pit (Photo 2). Power for the elevator controller must first enter a lockable safety disconnect device, located adjacent to the door of the equipment room. Of particular importance is the location of the disconnecting means so it can be found by an individual who may not be familiar with the installation. [emailprotected] ,l7CLHmcX9*F -{Q|^"XL`b1y]$,y *R/2Rn{\xG L*vMP.uKW,)68]Y}+ FYS1B=Q0S>Hc Home Articles Elevator World April 2012 Issue NEC Article 620: Elevators, Part I. 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). We have circuited the receptacles and lights in the pits to the same circuit. To avoid this situation, designers can specify elevator controls with a safety feature commonly called a rescuvator. 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. 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. The idea is quite simple. Design practices that are acceptable in some jurisdictions may not be in others. Suspending the cables from the supports by a means that automatically tightens around the cable when tension is increased for unsupported lengths up to 200 ft. An NEC Informational Note defines unsupported lengths. Shi Liguang, Yao Lianghong, Luo Zhiqun and Wan Jianru, Constructional Stretch and Hoist-Rope Tension . This is the area within the hoistway beneath the car, and there are occasions when elevator technicians have to work in this area for maintenance and troubleshooting. 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. 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. 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. As mentioned, traditional installations of a traction or hydraulic elevator include a separate machine room. Please check your entries and try again. Moreover, it is necessary to consider future worker safety for an indefinite period. Since 1953, Elevator World, Inc. has been the premier publisher for the global vertical transportation industry. Specifically, Section 725.43 provides that overcurrent protection for conductors 14 AWG and larger is to be provided in accordance with the conductor ampacity without applying ampacity adjustment and correction factors. Have wiring identified for use in wet locations in accordance with the requirements in NFPA 70. Lights and convenience outlets in elevator pits shall be installed to comply with the requirements of CCR, Title 24, Part 3, Article 620. By subscribing, you agree to our User Agreement and Privacy Policy & Cookie Statement. Indeed, most elevator accidents involve maintenance workers, yet even theirs is not an excessively dangerous profession. charlie b. 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. First, it is now clear that elevator controllers must be marked by the manufacturer with their SCCR. 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. Motors for traction elevators were traditionally DC or synchronous, but new installations use AC motors and VFDs for speed control. 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

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