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. The AHJ is saying that this is a violation of 620.23. Other codes and standards interact with the NEC, and it is necessary to see how they all work together in order to create safe and compliant elevator designs/installations. The simplest option is to use a shunt trip circuit breaker in either the feeder supplying the elevator or the elevator disconnect. These selective coordination tables for current-limiting fuses show the minimum amp ratio required between a pair of fuses of a given type(s) to achieve selective coordination. Modern electronic elevator controls can be sensitive to temperature shifts. +90 (216) 348 4876, India Office (Cross-sectional areas of conductors are given in Chapter 9, Tables 5 through 8. 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. Follow the manufacturers instructions and precautions. Fuses: Verify that the correct size, type and capacity are installed. The disconnecting means is also to be a listed device. Years may lapse between the design and installation stages of a project. Such vehicles include, but are not . Elevator motors are inherently intermittent duty. (g) Stop Switch in Pits. charlie b. Thus, the traveling cable must be supported by a steel supporting member. 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. Hydraulic elevators comprise a hydraulic reservoir, pump, cylinder, and controller. Special conditions: Troubleshooting in wet, hot or cold conditions calls for extra caution. 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. 836 Troy Schenectady Road ; Latham, NY 12110 . The light switch in the pit must be mounted 42 in. N _rels/.rels ( j0@QN/c[ILj]aGzsFu]U
^[x 1xpf#I)Y*Di")c$qU~31jH[{=E~ The usual scenario for electrical injury is shock when electrical current passes through the human body. Feeder and branch-circuit conductors are required to have specified ampacities: Feeder conductors of less ampacity are permitted for group installations and quite common in elevator work. This is typically accomplished via a shunt trip device. 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. Smoke detectors, which are required in all elevator lobbies and elevator equipment rooms, must be connected to the elevator controllers directly by means of auxiliary contacts and wiring, or indirectly by means of output signals from the fire alarm control panel. It employs specialists in Mobile, Alabama, and has technical and news correspondents around the world. 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. For circuit breakers, time-current curves must be consulted as well as the circuit breaker manufacturers selective coordination tables. By subscribing, you agree to our User Agreement and Privacy Policy & Cookie Statement. 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. Thus, the need for door interlock functionality is recognized. They are to be part of listed equipment, a driving machine or a driving-machine brake. 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. Based on the analysis, the arc-flash boundaries at the elevator/escalator controllers ranged from 3-16 in. Second, it must be configured so as to eliminate any chance of tangling or chafing against the inner surface of the hoistway or items mounted on it. The lighting is not to be connected to a GFCI, because the elevator car is not a place that should experience nuisance tripping. Required lighting shall not be connected to the load side of a ground-fault circuit interrupter. These are the principle NEC 2011 Article 620 mandates. 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. 23.254.250.15 The pump sends hydraulic fluid from the reservoir to the cylinder, buried deep below the elevator shaft. However, when I've put in elevators, NEC seems to always take a back seat to ANSI, which seems . 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. Three wiring categories within hoistways are allowed in addition, each with exceptions. 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. EazyLift Elevators, Stairlifts, Wheelchair Lifts & Ramps. Article 620 follows this pattern by opening, in Section I, General, with a statement of scope and definitions applicable to the topic under consideration. (To design and install an elevator for a Class I, Division 1 location would be quite an undertaking.). 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. 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 The cord is to be a hard-usage, oil-resistant type not over 6 ft. in length. In all cases, the working space must permit at least a 90 opening of equipment doors or hinged panels. Where the elevator shaft and/or equipment room has a sprinkler fire suppression system installed, the elevator Code requires main line power to the elevator be removed prior to the application of water. Elisha Otis safety elevator, introduced in 1853, prevented the fall of the car if the cable broke. Get more of Elevator World. Please include what you were doing when this page came up and the Cloudflare Ray ID found at the bottom of this page. Elevator Pit Drain or Sump Pump | UpCodes 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. Metal grating shall be installed over the hole that sits flush with the pit floor. An exception provides that liquid-tight flexible metal conduit or liquid-tight flexible nonmetallic conduit 3/8 in. Sign up for our free e-newsletter. The thinking behind this requirement is that the injured worker could have severe hand burns and be unable to operate a conventional doorknob. The electrical system designer needs to communicate this information to the person responsible for specifying the elevator controller, which is most often the architect. While machine room-less designs have been commercially available for many years, their use may still be unknown to some AHJs. So, we see that for elevator work, greater fill is allowed. 953 0 obj
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Traction elevators are typically faster and more energy efficient than hydraulic elevators, and are often used for high-rise buildings. (A) Separate Branch Circuit. 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. A traditional elevator installation (which includes a machine room) requires access inside the elevator shaft. 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. First, you'll need to install lighting in the elevator equipment room (Photo 1) and shaft pit (Photo 2). Article 620s Definitions section includes two terms that describe spaces not attached to the outside of a hoistway. Hydraulic elevators are typically more cost effective and used for buildings up to 5-6 stories. Because they need to move and flex, traveling cables are not required to be in a raceway. 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). 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). Otherwise, specify that the elevator supplier provide a battery back-up unit to power the lights in the event of an outage. 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. NEC 2011 also addresses branch circuits for machine room or control room/machinery space or control-space lighting and receptacles. 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. : inspecting; troubleshooting; observing; etc.) It employs specialists in Mobile, Alabama, and has technical and news correspondents around the world. Use the below learning-reinforcement questions to study for the Continuing Education Assessment Exam available online at www.elevatorbooks.com or on page 81 of this issue. Which equipment requires a separate branch circuit in the elevator car? Is lighting required to be GFCI protected in the machine room? Where is the lighting switch to be located in the machine room? What is the maximum raceway conductor fill in an elevator hoistway? How many disconnecting means are required for an elevator power supply? The various items to consider and check when designing for elevator installations have many potential pitfalls. Limit switches placed throughout the height of the shaft communicate with the controller and stop the cab at each landing. The demand factors are given in Table 620.14, which allows significant reductions as the number of motors is increased. The light switch shall be located so to be accessible from pit access door. There are several actions that could trigger this block including submitting a certain word or phrase, a SQL command or malformed data. Cross-sectional areas of wireways are found by multiplying the two interior dimensions.) (ASME has a separate document, A18.1-2008 Safety Standard for Platform Lifts and Stairway Lifts). The architect has a choice of either traction or hydraulic elevators. A second door is required if the equipment is rated over 1200 amps and over 6 ft. wide. The lighting switch shall be located so as to be readily accessible from the pit access door. If the equipment must remain energized to perform work, effective insulation and safe electrical working practices should be observed. Liquid-tight flexible nonmetallic conduit, Flexible cords and cables, or conductors grouped together and taped or corded, are permitted without raceway, where they are part of listed equipment, a driving machine or a driving-machine brake, Flexible metal conduit, liquid-tight flexible metal or nonmetallic conduit, 3/8 in. NEC Article 0: Elevator art by David Herres Continued. h-`7 In many cases, the overcurrent protective devices that are suitable for this level of protection are current-limiting fuses rather than a traditional circuit breaker. Where necessary, it is mandated that suitable guards be provided to protect the cables against damage. 988 0 obj
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Frequently Encountered Items That Delay Accep Tance of New Elevators And as the designer, you can become the fulcrum on which all of these requirements and authorities exert their leverage, but an understanding of elevator basics can help you handle the pressure. NEC Article 620 contains numerous other disconnect provisions, which must be carefully scrutinized prior to design work so the installation is compliant. 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. Selective coordination is also required for multiple elevators per NEC 620.62. This may be countered by providing good machine-room ventilation. This is especially true in an elevator shaft where measures have to be taken to ensure that a hazardous situation is not created. 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. 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. 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. 3016. Pits for Elevators. - California Department of Industrial Relations 3. 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. For example, an inadequately supported ceiling fan could fall and cause injury or property damage. Depending on your local codes, you can do this by installing heat or smoke detectors within 24 in. Eazylift Albany LLC, 836 Troy Schenectady Rd, Latham, NY, Elevators Corporate Office 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. Since 1953, Elevator World, Inc. has been the premier publisher for the global vertical transportation industry. 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. Another important electrical system design consideration for supplying power to multiple elevators is NEC 620.62. NFPA 72 requires the control circuit between the Fire Alarm System and the shunt trip be monitored for integrity. Sign up for our free e-newsletter. 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 idea is quite simple. Requirements in Article 620 modify the articles in Chapter 3. ASME A17.1 . You must locate this key switch at the main lobby or at the building fire command center. To achieve flexibility and endurance, traveling cable is more finely stranded and, where possible, separated into discrete conductors. NEC has a further note that the term wheelchair lift has been changed to platform lift.. This room is to be secured against unauthorized access (kept locked). Guidance in determining whether elevator pits meet the definition of 4.0 (2 Reviews) (2) CLAIMED . Traveling cables are to be supported by one of these means: Looping the cables around supports for unsupported lengths less than 100 ft. APPENDIX A 2.2. 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. IAEI News Magazine. The surest means of avoiding an arc-flash hazard is to lockout and tagout the electrical service to a controller. This equipment is restricted to that used in connection with the specific elevator, dumbwaiter, escalator, moving walk, platform lift or stairway chairlift. Pit light with guard (ten foot candles min. Other terms defined in NEC Article 620 are Control System, Motion Controller, Motor Controller, Operation Controller, Operating Device and Signal Device. Please check your entries and try again. 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. +1-251-479-4514 | [emailprotected], Trkiye Office The code exempts some fairly broad areas where compliance is not expected. Finally, in 1897, the first National Electrical Code (NEC) appeared. GFI Receptacles: GFI receptacles shall be required in all elevator machine rooms, machinery spaces and elevator pit areas. 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. NEC 2011 Article 620.21(2)(b) states that hard-service cords and junior hard-service cords that conform to the requirements of Article 400 (Table 400.4) are permitted as flexible connections between the fixed wiring on the car and devices on the car doors or gates. from the exposed components, and the incident energy calculated at 18 in. Always verify all conditions and requirements with the state and the AHJ where the installation is taking place. 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. Notice the definition mentions the full range of operating times. This is something that can be easily accomplished if the elevator controller manufacturer uses components in combination with overcurrent protective devices that are tested and listed with high combination SCCRs. In contrast to the lighting, these receptacles must be connected to GFCI devices. The main concern is to ensure that workers may escape to safety in the awful circumstance of an arc-fault event. Even though Edison grasped the basic ideas of fusing and overcurrent protection, many hazards remained. It does specify wiring methods allowed, though, in 620. These conductors may be covered with suitable shielding for telephone, audio, video or higher-frequency communications circuits. We resume with a look at wiring methods, overcurrent protection, grounding and other NEC provisions as they relate to these installations. Traditionally, the electrical system design engineer has given little attention to the elevator controller. This may be countered by providing good machine-room ventilation. 974 0 obj
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Traditional wiring methods and materials come into play, as always, but it is necessary to rethink their deployment. 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. Even non-composite fiber-optic cable, which does not carry electrical energy, is subject to the code. Hard-service cords and junior hard-service cords are permitted as flexible connections between the fixed wiring on the car and devices on the car doors or gates. The next section, 620.36, concerns different systems in one raceway or traveling cable. 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. The conductors must be in their original sheaths or grouped together and taped or corded. It is further stressed that no provision is to be made to open or close the disconnecting means from any other part of the premises. The disconnecting means is to be an externally enclosed, operable, fused motor circuit switch or circuit breaker capable of being locked in the open position. The cover shall be secured and level with the pit floor. 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). These may include: The author would like to recognize Jonathan Kennedy for his assistance in creating this article. 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. It is further specified the machine-room lighting switch be located at the point of entry. Every building is different. This clear working space must be 30 in. The action you just performed triggered the security solution. 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. We have circuited the receptacles and lights in the pits to the same circuit. The fire loading resulting from an accumulation of abandoned low-voltage cabling may be considerable, and has to be understood and dealt with. Additionally, duty on elevator and dumbwaiter motors is rated as intermittent, whereas duty on escalator and moving-walk motors is considered continuous. 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. (C) Duplex Receptacle. hbbd```b``+3dL
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[emailprotected] Additionally, ampacities of the individual conductors and flame-retardant properties of the overall cable are important factors. 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. Many new buildings are incorporating an elevator design that does not include an equipment room (sometimes called machine room-less elevators). PDF Q.When and where are GFCI's required by the NC Electrical Code 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. 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). Be sure to provide a horn/strobe alarm in large equipment rooms because they can be noisy, isolated places. The basic idea is that there must be a separate, dedicated circuit for car lights, receptacles and ventilation on each car. ,l7CLHmcX9*F -{Q|^"XL`b1y]$,y *R/2Rn{\xG
L*vMP.uKW,)68]Y}+ FYS1B=Q0S>Hc Louisiana State Uniform Construction Code Council adopts the 2014 NEC, Basic three-phase power measurements explained, Safety After the Storm Operating Portable Generators. 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. 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 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. After such an event, it is important that the affected worker is able to escape the area and get to help. It is important for the design engineer to coordinate with the architect to determine the elevator manufacturer basis of design to determine if and when additional power and lighting is required. 2.2.6.1 This switch shall be so located as to be acces-sible from the pit access door. The drain or sump pump discharge shall be into the sanitary or storm drainage system through an indirect waste connection. ), 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. Good documentation is of key importance to recalling what decisions were made and why. . 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. You need to Subscribe to continuing reading. With the new elevator controller requirements, more attention will be focused on the elevator system. U.S. Latham, NY Shopping Miscellaneous Retail Stores, NEC Wheelchair lifts EazyLift Elevators, . from components that are not otherwise guarded. However, this can vary depending on building conditions and exterior grade. 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. (B) Lighting Switch. Related Code Sections 802.1.8 Indirect/Special Waste, Elevator Pit Drain or Sump Pump The two documents are in harmony and should be used in conjunction. , !! The elevator controller manufacturer must determine the required elevator controller SCCR as stated in the elevator controller specification and provide an elevator controller SCCR that is equal to or greater than the available fault current thats indicated in the design documents where there are multiple elevator controllers at different locations. A section on branch circuits for car lighting, receptacles, ventilation, heating and air-conditioning contains a number of important provisions.
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