The Electrical Ups and Downs of Elevator Design | EC&M Later in the 19th century, Thomas Edison and his associates built an electrical distribution system in Lower Manhattan. Because of this, there is often a communications gap between the electrical system designer, whose design typically stops at the required elevator disconnecting means, and the architect who designs the elevator system. These may include: The author would like to recognize Jonathan Kennedy for his assistance in creating this article. However, when I've put in elevators, NEC seems to always take a back seat to ANSI, which seems . CLAIMED . We resume with a look at wiring methods, overcurrent protection, grounding and other NEC provisions as they relate to these installations. NEC Guidelines on Commercial Garages. On existing or listed equipment, conductors are permitted to be grouped together and taped or corded without being installed in a raceway. PK ! 2m9 `K]f*F gaR
The elevator pit discharge system is not required to include an oil separator, except as required by section 1003.4. Weight (passengers, freight, car and attendant machinery) may be fairly substantial, and speed is significant. Selective coordination is also required for multiple elevators per NEC 620.62. 3016. Pits for Elevators. - California Department of Industrial Relations It is also worth mentioning that the stated purpose of the NEC is the practical safeguarding of persons and property from hazards arising from the use of electricity. And so the needs can be very different. 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. 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. 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. Corporate Office 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. Traveling cables are to be supported by one of these means: Looping the cables around supports for unsupported lengths less than 100 ft. Something went wrong. Upon loss of power, the rescuvator controls the cab, lowers it to the designated floor, and opens its doors. 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). Design practices that are acceptable in some jurisdictions may not be in others. The simplest option is to use a shunt trip circuit breaker in either the feeder supplying the elevator or the elevator disconnect. 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. Generally, it is decreed that the supply voltage is not to exceed 300 V between conductors (allowing for the familiar 240-V concept), although there are exceptions. 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. Part III, Wiring, looks at the types of wiring that may be installed in hoistways, cars, machine rooms and related spaces. To avoid this situation, designers can specify elevator controls with a safety feature commonly called a rescuvator. The same figure applies to nonmetallic wireways. So, we see that for elevator work, greater fill is allowed. Many of these are for portable lighting.). The new ADAAG guidelines now require that emergency power be available to elevators that have four or more stories of travel above or below the accessible floor [4.1.3(9)(1)]. They are differentiated from other similar structures by the fact that they are not attached to the outside perimeter or surface of the walls, ceiling or floor of the hoistway. Cloudflare Ray ID: 7a2fbe9ebd7e2fe8 To achieve flexibility and endurance, traveling cable is more finely stranded and, where possible, separated into discrete conductors. He is saying that each pit requires a separate circuit, in other words "dedicated". 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. 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. PDF Compliance with the 2017 NEC for Elevator Controllers Dan Neeser is a Senior Field Application Engineer with Eatons Bussmann Division. But the lights don't have to be in the pit itself. Flexible cords and cables part of listed equipment operating at 30 V (42 VDC) or less, similarly supported and protected, jacketed and flame retardant, are permitted. This will normally require you to vent the room with a fire/smoke damper and include smoke detector signals in the control logic. In addition, requirements for selective coordination and shunt tripping should be complied with as needed for the installation. The pump sends hydraulic fluid from the reservoir to the cylinder, buried deep below the elevator shaft. Motors for traction elevators were traditionally DC or synchronous, but new installations use AC motors and VFDs for speed control. A second door is required if the equipment is rated over 1200 amps and over 6 ft. wide. For instance, a typical elevator controller may traditionally have SCCR ratings from 5 to 10 kA. The fan should be on a dedicated circuit. Marking the elevator controller short-circuit current rating (SCCR) by the elevator controller manufacturer. Utility-owned electrical structures not directly concerned with electrical generation, transmission and distribution are NEC regulated. . These are covered for generic, non-elevator specific use in earlier articles, 376 and 378, in Chapter 3, Wiring Methods and Materials. The drain or sump pump discharge shall be into the sanitary or storm drainage system through an indirect waste connection. PDF Electric Elevator Checklist Cover Page - Oregon All Rights Reserved | Contact Us | Privacy Policy. 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. High-rise buildings pose additional concerns. First, the ATS signals the elevators that it's about to switch over to emergency power preferably 30 sec or more prior to switching, which allows the elevator controller to bring each elevator cab to the nearest landing and stop, thus protecting the motors and electrical system. In some cases, it may require a means to test the shunt trip operation or have one contact operate the shunt trip of more than one elevator. (Cross-sectional areas of conductors are given in Chapter 9, Tables 5 through 8. 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. f?3-]T2j),l0/%b 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. 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. 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. With heavy use on a hot day, the oil can overheat, causing elevator shutdown. You'll be responsible for specifying the items related to the fire alarm and some controls, as well as supplying lighting and power to the equipment room and elevator pit. 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. 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 basic wiring methods are rigid-metal, rigid nonmetallic or intermediate-metal conduit; electrical metallic or rigid nonmetallic tubing; wireways; or Type MC, MI or AC cable, unless otherwise permitted. or larger, not over 6 ft. in length. As mentioned, traditional installations of a traction or hydraulic elevator include a separate machine room. 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. Dont troubleshoot unless you can keep your shoe/boot soles dry. Hydraulic reservoir characteristic of a hydraulic-piston-operated elevator. These must also be insulated for the maximum voltage applied to any conductor within the cable or raceway system. Fuses: Verify that the correct size, type and capacity are installed. The conductors must be in their original sheaths or grouped together and taped or corded. Depending on your local codes, you can do this by installing heat or smoke detectors within 24 in. Performance & security by Cloudflare. Elevator PITS | Mike Holt's Forum +1-251-479-4514 | [emailprotected], Trkiye Office This is typically accomplished via a shunt trip device. endstream
endobj
954 0 obj
<. 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 Hydraulic elevator pit | Electrician Talk Elevator Sump Requirements - Risi Stone Inc. Conductors supplying a single power transformer are to have an ampacity not less than the nameplate current rating of the power transformer plus all other connected loads. The cord is to be a hard-usage, oil-resistant type not over 6 ft. in length. NEC Article 620: Elevators, Part 2 - Elevator World, Inc. 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. A further requirement concerns elevator-car air-conditioning and heating. 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. 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. Get more of Elevator World. . If a hydraulic elevator loses power because a heat detector goes off or for any other reason it could trap occupants for an unpleasant amount of time. These are part of Article 725, Class 1, Class 2 and Class 3 Remote-Control, Signaling, and Power-Limited Circuits. For instance, one method to reduce the available fault current is to add an isolation transformer ahead of the elevator controller. 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. Freight Elevator Door Control: An Opportunity for Wireless Technology. Elevator Pit FC Requirements CE017 - 1 - AppendicesABC - Code Flexible cords and cables, or conductors grouped together and taped or corded, are permitted to be installed without a raceway. 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. The fan should be on a dedicated circuit. Power for the elevator controller must first enter a lockable safety disconnect device, located adjacent to the door of the equipment room. 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. 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. 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. Article 620 follows this pattern by opening, in Section I, General, with a statement of scope and definitions applicable to the topic under consideration. Many NEC articles address voltage limitations, and Article 620 is no exception. Good documentation is of key importance to recalling what decisions were made and why. 354 Morgan Ave. The action you just performed triggered the security solution. 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. 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. In driving through commercialized suburban areas, you frequently see paralleled conductors for large retail grocers (where there is a heavy refrigeration load). If the equipment must remain energized to perform work, effective insulation and safe electrical working practices should be observed. 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. If it kills the son of the owner, the son of that builder shall be put to death.. Your elevator supplier will take care of all the wiring and related code requirements for the elevator cab and the various controls. All rights reserved. 4.0 (2 Reviews) (2) CLAIMED . Be sure to provide a horn/strobe alarm in large equipment rooms because they can be noisy, isolated places. [emailprotected] +90 (216) 348 4876, India Office 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. 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. 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. 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. 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. from the exposed components, and the incident energy calculated at 18 in. 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 this is not done and the available fault current exceeds the elevator controller SCCR, other solutions to reduce fault current must be reviewed or equipment changes and field evaluations may be needed. My reasoning comes from 620.24 (A) and (C). 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. He has focused on writing since 2006, having written for such magazines as ELEVATOR WORLD, Electrical Construction and Maintenance, Cabling Business, Electrical Business, Nuts and Volts, PV Magazine, Electrical Connection, Solar Connection, Solar Industry Magazine, Fine Homebuilding Magazine and Engineering News. 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. 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. Additionally, ampacities of the individual conductors and flame-retardant properties of the overall cable are important factors. A single means for disconnecting all ungrounded main power-supply conductors is required and must be designed so no pole can be operated independently. If we fast forward more than 36 centuries, we see some important new developments in elevator technology. Be sure to provide a horn/strobe alarm in large equipment rooms because they can be noisy, isolated places. 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.. 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. NEC has a further note that the term wheelchair lift has been changed to platform lift.. [emailprotected] NEC Article 620 contains numerous other disconnect provisions, which must be carefully scrutinized prior to design work so the installation is compliant. Building codes were deemed necessary to protect the public against shoddy builders and outmoded construction techniques. above the seal plate, adjacent to the ladder. The electrical energy does not traverse the human body, but proximity to the explosion means severe injury is possible from the intense heat and concussive shockwave. Compliance with the 2017 NEC for Elevator Controllers [emailprotected] 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. The disconnecting means is to be in the machine room or similar location, with provision for being locked in the open position. 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. ^W i word/document.xml=nr]6Id=,_$j9-"Y.iGU\h_}. You need at least one 120VAC GFCI-protected receptacle at each location. 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. This lighting and receptacle circuit is separate from the circuit serving the motor. +1-251-479-4514 | [emailprotected], Trkiye Office 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. 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. . DOCX 26 80 00 - Elevator Electrical Requirements - University of Illinois It is mandatory, as in the car, that these items have a separate, dedicated branch circuit, and the required lighting is not to be supplied through a GFCI. Pits shall be maintained in a clean and dry condition. But, building codes had been in existence for many centuries. 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. The lighting is not to be connected to a GFCI, because the elevator car is not a place that should experience nuisance tripping. Bonding of elevator rails to a lightning-protection system grounding conductor is permitted, but the conductor itself is not to be located in the hoistway. As stated in Section 7 of the Elevator Industry Field Employees Safety Handbook: Unless it is not feasible, (i.e.