The electrical system designer calculates the maximum available fault current at the elevator controller. 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? This is because the material may contribute fuel to a fire that has originated elsewhere. The same figure applies to nonmetallic wireways. 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. As they review the plans and the construction site, they may have conflicting interpretations or requirements. Because they need to move and flex, traveling cables are not required to be in a raceway. ,l7CLHmcX9*F -{Q|^"XL`b1y]$,y *R/2Rn{\xG
L*vMP.uKW,)68]Y}+ FYS1B=Q0S>Hc This, however, can result in a dramatic increase in cost, space availability (lack thereof), and reduced efficiency. Supports for cables or raceways in a hoistway or in an escalator or moving-walk wellway or platform lift and stairway chairlift runway must be securely fastened to the guide rail, escalator or moving-walk truss, or to the hoistway, wellway or runway construction. ) > word/_rels/document.xml.rels ( N0HC;qRN/W$#{1EM]ZY|vj5h),-g!`./V/KKFY4D#la&V#=$Q7|l/d#hS 7+IDZ!J 6KucD^s`+>=(3E He also required GFCI protection for the hard-wired sump pump that did not require it. (A) tells us that the lighting and receptacle (s) for the pit must be on separate circuits. NEC has a further note that the term wheelchair lift has been changed to platform lift.. 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. 3. 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). 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. These must also be insulated for the maximum voltage applied to any conductor within the cable or raceway system. They must be in enclosures with doors or removable panels that can be locked in the closed position. ), advise the building owner to correct the condition. 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. Luminaires must be lensed or equipped with wire guards to protect the lamps. NEC 620.62 requires the elevator disconnecting means (fused switch or circuit breaker) to selectively coordinate with all supply-side overcurrent devices. 23.254.250.15 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. 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. 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. 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. Please include what you were doing when this page came up and the Cloudflare Ray ID found at the bottom of this page. Many of these are for portable lighting.). Metallic articles: Remove metallic articles such as watches, chains, bracelets, earrings, belt buckles and keychains before troubleshooting. 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. 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. Selective coordination is also required for multiple elevators per NEC 620.62. Required lighting shall not be connected to the load side of a ground-fault circuit interrupter. NEC Article 620 Part V, Traveling Cables, is driven by two major issues.
Please check your entries and try again. If we fast forward more than 36 centuries, we see some important new developments in elevator technology. 1993 NEC 15-20 Amp 120 volt Receptacle Requirements: Wet bar sinks, all bathrooms, roof tops, elevator machines rooms, elevator car tops, elevator pits. 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. Personal protective equipment (PPE): Use appropriate PPE to protect body parts within the range of 3-16 in. All rights reserved. +91 8025357028, 2022 Elevator World, LLC. If you provide your elevators with emergency power, you must run communications wires between the automatic transfer switch (ATS) and the elevator control panel. Similar provisions are attached to elevator-car heating and air-conditioning disconnecting means, and to other utilization equipment. Though I understand how someone might argue two. 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. And so the needs can be very different. To avoid this situation, designers can specify elevator controls with a safety feature commonly called a rescuvator. It is worth noting that these NEC terms, used throughout Article 620, have been chosen to correlate with A17.1-2007 usage. This is especially true in an elevator shaft where measures have to be taken to ensure that a hazardous situation is not created. Good documentation is of key importance to recalling what decisions were made and why. These are the principle NEC 2011 Article 620 mandates. Elevators with driving machines located on the car or counterweight, or in the hoistway are permitted outside the specified spaces. Since 1953, Elevator World, Inc. has been the premier publisher for the global vertical transportation industry. They are to be part of listed equipment, a driving machine or a driving-machine brake. Depending on your local codes, you can do this by installing heat or smoke detectors within 24 in. A single dedicated receptacle supplying a permanently installed sump pump does not have to be a GFCI type. 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. 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. Something went wrong. In case of emergency, electricians, maintenance personnel and any elevator technicians called in to the premises should have ready access to the key. You'll need to run telephone cables to the equipment room control panel, but the elevator supplier will take care of getting the cables to the elevator cab. Shi Liguang, Yao Lianghong, Luo Zhiqun and Wan Jianru, Constructional Stretch and Hoist-Rope Tension . But by understanding how these items fit together and what purpose they serve, you can have a successful project. Part IX, Grounding, states that metal raceways, Type MC cable, Type MI cable or Type AC cable attached to elevator cars are to be bonded to metal parts of the car bonded to the equipment grounding conductor. Traveling cables are to be supported by one of these means: Looping the cables around supports for unsupported lengths less than 100 ft. If you specify a rescuvator, you must also specify a disconnect switch with an auxiliary contact that opens when the disconnect arm moves to the open position, but stays closed when the OCPD trips. Here again, the lighting is not to be connected to a GFCI, whereas such protection is required for the receptacle(s). Each of these performs a different function, and the wiring mandates vary accordingly. Dec. 21, 2010. Installing electrical equipment where its SCCR is less than the available short-circuit current creates serious safety hazards. The circuit(s) for the lighting and receptacles must be dedicated to the elevator area only. The elevator equipment room that serves a hydraulic elevator is almost always located on the lowest floor adjacent to the elevator shaft. 836 Troy Schenectady Road Latham, NY 12110 . In a time when increasing value is placed on even small amounts of real estate, elevator design must strive to configure, efficiently control and drive elements to whatever degree possible, and that is the thinking behind some alternate locations for these structures. 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. In Part One of this series (ELEVATOR WORLD, April 2012), we began an examination of National Electrical Code (NEC) 2011 mandates for elevators and related equipment installations. Hazards created by water, snow or condensation in the work area can cause slips, falls and accidental contact. A separate branch circuit shall supply the hoistway pit lighting and receptacle (s). You are a subscriber that needs to Sign In. Requirements in Article 620 modify the articles in Chapter 3. The next section, 620.36, concerns different systems in one raceway or traveling cable. Hydraulic elevators comprise a hydraulic reservoir, pump, cylinder, and controller. The traveling cable, of necessity, is exempted. Many professionals believe the NEC is applicable only for voltages over a certain level, but that is not the case. Next, with multiple elevator banks, the controller will usually allow only one elevator at a time to operate, reducing the amount of emergency power required. Part VIII, Machine Rooms, Control Rooms, Machinery Spaces, and Control Spaces, states elevator and similar-installation driving machines, motor-generator sets, motor controllers and disconnecting means are to be installed in a room or space set aside for that purpose. hbbd```b``+3dL
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The lighting is not to be connected to a GFCI, because the elevator car is not a place that should experience nuisance tripping. (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. As mentioned, traditional installations of a traction or hydraulic elevator include a separate machine room. 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. Notice the definition mentions the full range of operating times. Get more of Elevator World. or larger, not exceeding 6 ft. in length, are permitted between control panels and machine motors, machine brakes, motor-generator sets, disconnecting means and pumping motors and valves. +;-mka|7! 2m9 `K]f*F gaR
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. Elevator power disconnect (with utility feed marking) located in the machine room or other permitted location. 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. +90 (216) 348 4876, India Office Fireman telephone jacks and telephone cabling are typically sufficient for each of these locations. 1. When you consider that an elevator is an enclosed room with one or more doors that people voluntarily enter so they may travel hundreds of feet up or down, several observations are in order. Mobile, AL 36606 USA 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. Based on the analysis, the arc-flash boundaries at the elevator/escalator controllers ranged from 3-16 in. 836 Troy Schenectady Road ; Latham, NY 12110 . These may include: The author would like to recognize Jonathan Kennedy for his assistance in creating this article. These circuit breaker selective coordination tables can be used to identify the maximum fault current that a pair of circuit breakers can selectively coordinate. 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. 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. In addition, requirements for selective coordination and shunt tripping should be complied with as needed for the installation. ^W i word/document.xml=nr]6Id=,_$j9-"Y.iGU\h_}. This accomplishes two functions. f?3-]T2j),l0/%b [emailprotected] You can email the site owner to let them know you were blocked. z, /|f\Z?6!Y_o]A PK ! Article 620s Definitions section includes two terms that describe spaces not attached to the outside of a hoistway. As we have seen, a limited number of these are approved for elevator locations car, hoistway, pit and machine room. One way to achieve this is by paralleling wires, i.e., connecting the runs at both ends so they are physically like two wires but electrically one. You need to Subscribe to continuing reading. The proposals resulted in adding new requirements in the 2017 NEC for: This article will also discuss other Code requirements that include selective coordination for elevators that are supplied by emergency, legally required standby or critical operation power systems or multiple elevators supplied from a single feeder, and shunt tripping of elevators where the elevator equipment room and/or shaft has a fire suppression sprinkler system. This device must be either a fused disconnect or a circuit breaker because ANSI/ASME A17.1 requires you to install an additional overcurrent protection device (OCPD) in the elevator equipment room. Such design innovations require sophisticated wiring strategies. Firefighters can then use portable telephone handsets in combination with the jacks and cabling. Selective coordination is also required for multiple elevators per NEC 620.62. These are the individual branch circuits required for car lighting, receptacles, auxiliary lighting and ventilation on each elevator car; individual branch circuits for machine-room and similar location lighting and receptacle; and branch circuits for hoistway pit lighting and receptacle(s). Thus, the need for door interlock functionality is recognized. 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. 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. Where a feeder powers more than one elevator, you need selective coordination; the OCPDs must be series-designed so a fault at one of the elevators will be cleared by only the OCPD serving it. The demand factors are given in Table 620.14, which allows significant reductions as the number of motors is increased. For instance, a typical elevator controller may traditionally have SCCR ratings from 5 to 10 kA. Hard-service cords are permitted only as flexible connections for the top-of-car operating device or the car-top work light.
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