Traditional wiring methods and materials come into play, as always, but it is necessary to rethink their deployment. 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. 4.0 (2 Reviews) (2) CLAIMED . 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) He participates in IEEE (Senior Member) with Industrial and Commercial Power Systems, NEMA (member of the Codes & Standards Committee), NFPA (committee member for NEC CMP-13 and NFPA 79), UL (508/60947 and 508A) and IAEI activities. Main feeders that supply elevator power must be kept outside the hoistway unless one of the following applies: Feeders for elevators are permitted within an existing hoistway (provided they are not spliced within the hoistway) by special permission of the AHJ. Regardless of the number of elevators, only one smoke detector is required at each floor lobby, but it must be located within 21 ft of every elevator door. from the exposed components, and the incident energy calculated at 18 in. First, the traveling cable must be composed of very fine-stranded conductors so it can flex with a minimum of internal stresses, ensuring long service life and reliability. Part X, Emergency and Standby Power Systems, is simple and straightforward. This is especially true in an elevator shaft where measures have to be taken to ensure that a hazardous situation is not created. 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. NEC Article 620 Part IV, Installation of Conductors, contains key mandates for elevator wiring. 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. 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. But by understanding how these items fit together and what purpose they serve, you can have a successful project. Traditionally, the electrical system design engineer has given little attention to the elevator controller. Elevators with driving machines located on the car or counterweight, or in the hoistway are permitted outside the specified spaces. Overcurrent devices protecting these branch circuits are to be located in the machine room or similar location. Utility-owned electrical structures not directly concerned with electrical generation, transmission and distribution are NEC regulated. I've never run into this before. 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. If you provide your elevators with emergency power, you must run communications wires between the automatic transfer switch (ATS) and the elevator control panel. Where necessary, it is mandated that suitable guards be provided to protect the cables against damage. A traditional elevator installation (which includes a machine room) requires access inside the elevator shaft. The light switch shall be located so to be accessible from pit access door. Elevator power disconnect (with utility feed marking) located in the machine room or other permitted location David Herres David Herres holds a New Hampshire Master Electrician's license and has worked as an electrician in the northern part of that state for many years. (A) tells us that the lighting and receptacle (s) for the pit must be on separate circuits. 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. These are part of Article 725, Class 1, Class 2 and Class 3 Remote-Control, Signaling, and Power-Limited Circuits. A second door is required if the equipment is rated over 1200 amps and over 6 ft. wide. The 12 definitions provided in NEC 2011, Section 620.2 are the place to start for guidance in this area, and the sections that follow lay out implementation guidelines that are very relevant in todays environment. Similarly, the integrity of the traveling cable is emphasized. 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. 2m9 `K]f*F gaR
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The various items to consider and check when designing for elevator installations have many potential pitfalls. Provide continuous, non -slip, horizontal rungs every 12" for the full height of the pit ladder. He is saying that each pit requires a separate circuit, in other words "dedicated". NEC 2011 also addresses branch circuits for machine room or control room/machinery space or control-space lighting and receptacles. NEC Article 0: Elevator art by David Herres Continued. 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 (f) Illumination of Pits. Apr 24, 2013. correct me if I'm wrong, but I believe it's damp. In fact, an entire elevator system for a project is most often designed and specified by the architect who has little understanding of the electrical distribution system. First, it is now clear that elevator controllers must be marked by the manufacturer with their SCCR. Dec. 21, 2010. 2. 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. To address this issue, Code Making Panel (CMP) 12 of the National Electrical Code acted on several proposed changes to Article 620 during the revision cycle for the 2017 NEC that deal with the proper installation of elevator controllers. 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.. Something went wrong. N _rels/.rels ( j0@QN/c[ILj]aGzsFu]U
^[x 1xpf#I)Y*Di")c$qU~31jH[{=E~ These are: remote machine room and control room (for elevator and dumbwaiter), and remote machinery space and control space (for elevator and dumbwaiter). Guidance in determining whether elevator pits meet the definition of The demand factors are given in Table 620.14, which allows significant reductions as the number of motors is increased. 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)]. 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. 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. NEC Article 620 covers elevators, dumbwaiters, escalators, moving walks, platform lifts and stairway chairlifts. Something went wrong. (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. +91 8025357028, 2022 Elevator World, LLC. 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. NEC Article 620 Part VI, Disconnecting Means and Control, is rather exacting. Fuses: Verify that the correct size, type and capacity are installed. After such an event, it is important that the affected worker is able to escape the area and get to help. David Herres Flexible metal, liquid-tight flexible metal or liquid-tight flexible nonmetallic conduit 3/8 in. If the entire feeder/branch circuit assembly were to be protected in the conventional manner, the motor would cut out long before reaching operating speed. Get more of Elevator World. High-rise buildings pose additional concerns. It is worth noting that these NEC terms, used throughout Article 620, have been chosen to correlate with A17.1-2007 usage. Similarly, motor branch-circuit short circuit and ground-fault protection must be as required in Article 430, Part IV, for all motors. 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. The code exempts some fairly broad areas where compliance is not expected. 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. 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. , !! +90 (216) 348 4876, India Office 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. My reasoning comes from 620.24 (A) and (C). It provides that where more than one driving-machine disconnecting means is supplied by a single feeder, the overcurrent protective devices in each disconnecting means are to be selectively coordinated with any other supply side overcurrent protective devices. Moreover, because motors have a higher starting current than other loads, the overcurrent protection protocol is unique to them and somewhat counterintuitive. Hazards created by water, snow or condensation in the work area can cause slips, falls and accidental contact. The fire loading resulting from an accumulation of abandoned low-voltage cabling may be considerable, and has to be understood and dealt with. The many codes and guidelines that regulate the electrical design of an elevator can seem overwhelming, and dealing with the electrical inspector, elevator inspector, and Fire Marshal can be even more intimidating. The Code provides guidance through regulations to establish requirements. 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. Many of these are for portable lighting.). As stated in Section 7 of the Elevator Industry Field Employees Safety Handbook: Unless it is not feasible, (i.e. Requirements for commercial garages per the National Electrical Code. So, we see that for elevator work, greater fill is allowed. With the new elevator controller requirements, more attention will be focused on the elevator system. Finally, typical installations and compliance with all these requirements will be discussed. 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. 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. Elevator power disconnect (with utility feed marking) located in the machine room or other permitted location. Dont troubleshoot unless you can keep your shoe/boot soles dry. The electrical conductors and equipment for non-mine elevators that extend below grade are under NEC jurisdiction. ASME A17.1, Section 2.2.5, National Electrical Code, Rule 620-85 4. 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. q!^mDtsnEX3_ shvqu+X9@w3gSj`g Home Articles Elevator World April 2012 Issue NEC Article 620: Elevators, Part I. Many people use portable generators until power is restored. 2.2.2.6 . 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. Installing electrical equipment where its SCCR is less than the available short-circuit current creates serious safety hazards. Louisiana State Uniform Construction Code Council adopts the 2014 NEC, Basic three-phase power measurements explained, Safety After the Storm Operating Portable Generators. 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. 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. !>x=yy Bvv8?~e PK ! (A) Separate Branch Circuit. 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). +90 (216) 348 4876, India Office Home Articles Elevator World June 2012 Issue NEC Article 620: Elevators, Part 2. endstream
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PDF Elevator Safety Program - Technical Clarification Requirements in Article 620 modify the articles in Chapter 3. The architect has a choice of either traction or hydraulic elevators. 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. 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. 953 0 obj
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The disconnecting means must disconnect the elevator from the emergency, standby and normal power systems. A surge of immigration to the U.S., the end of slavery and, on both sides of the Atlantic Ocean, a burgeoning industrial revolution ignited an acceleration in new building. 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. Click to reveal 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. While the definitions are straightforward, their deployment in real-life building projects involves enormous legal and moral implications, given the fact that we are carrying large numbers of people hundreds of feet above the earths surface on a daily basis. h-`7 NEC 620.62 requires the elevator disconnecting means (fused switch or circuit breaker) to selectively coordinate with all supply-side overcurrent devices. The traveling cable, of necessity, is exempted. Guarding: Where possible, install temporary guarding to protect from inadvertent contact. Every building is different. With the elevator car at the bottom landing, it is the length of cable as measured from the point of suspension in the hoistway to the bottom of the loop. 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. 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. The Electrical Ups and Downs of Elevator Design | EC&M 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. EazyLift Elevators, Stairlifts, Wheelchair Lifts & Ramps. The code notes that elevator rails or other hoistway equipment are not to be used as the grounding conductor for lightning-protection systems. 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. 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. It states an elevator is permitted to be run by an emergency or standby power system. A traction elevator's equipment room is typically located at the top of the building, directly over or adjacent to the shaft. If we fast forward more than 36 centuries, we see some important new developments in elevator technology. 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. Please check your entries and try again. Motor controllers are permitted outside the spaces specified above. 6 feet, and shall meet the requirements of NEC 70 620.21(A)(1)(d). Flexible cords and cables in lengths not to exceed 6 ft. of a flame-retardant type and located to be protected from physical damage are permitted in machine rooms without being installed in a raceway. You need to Subscribe to continuing reading. Sign up for our free e-newsletter. Jul 15, 2021. 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. 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. 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. ASME A17.1 . If power is not being supplied to the elevator controller (e.g., open mainline fuses, etc. In elevators provided with Firefighters' Emergency Operation, a drain or sump pump shall be provided. All Rights Reserved | Contact Us | Privacy Policy. Machine room/control space lighting and receptacles 4. Always verify all conditions and requirements with the state and the AHJ where the installation is taking place. endstream
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<. 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. The hazards are external to the equipment enclosure since equipment SCCR testing and evaluation criteria for product standards are most often performed with the enclosure doors closed and latched, and the fault occurring external to the enclosure. In these installations, it is best to design the elevator controller so the elevator controller SCCR is adequate for the available fault current. 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. Luminaires must be lensed or equipped with wire guards to protect the lamps. Machine room-less elevator installations incorporate the elevator controller and often the primary disconnecting means in a convenient package that is located within the elevator shaft. 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. Proper selective coordination in a multi-elevator installation on the same feeder ensures if one elevator develops a fault, the other units will not be shut down. This is somewhat broader than A17.1-2007/B44-07. As an installer and an inspector, one common issue I've seeen is incompatible connections associated with raceways connections and fittings. If the equipment must remain energized to perform work, effective insulation and safe electrical working practices should be observed. C.1.4 ELEVATOR PIT REQUIREMENTS 1. z!0: - [Content_Types].xml ( n0EUb*>-RxV=QUAl"93dFk%Y?l}MGDV Metallic articles: Remove metallic articles such as watches, chains, bracelets, earrings, belt buckles and keychains before troubleshooting. U.S. Latham, NY Shopping Miscellaneous Retail Stores, NEC Wheelchair lifts EazyLift Elevators, . The next section, 620.36, concerns different systems in one raceway or traveling cable. Hydraulic reservoir characteristic of a hydraulic-piston-operated elevator. These conductors may be covered with suitable shielding for telephone, audio, video or higher-frequency communications circuits. 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. It is worth mentioning that when 600 V is talked about as a limit in the NEC, it is generally meant that the familiar 600-V nominal-voltage system is considered to lie within the permitted zone, making it a common usage. These circuit breaker selective coordination tables can be used to identify the maximum fault current that a pair of circuit breakers can selectively coordinate. Convenience receptacles and lighting for maintenance purposes are required at the base of the pit and, in some instances (elevator manufacturer dependent), at the top of the elevator shaft. The branch circuit supplying these units is to be similarly dedicated, with the associated overcurrent device located in the machine room or similar location. 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. However, when I've put in elevators, NEC seems to always take a back seat to ANSI, which seems . By subscribing, you agree to our User Agreement and Privacy Policy & Cookie Statement. First, you'll need to install lighting in the elevator equipment room (Photo 1) and shaft pit (Photo 2). Hint: Duct Tape to the Rescue, NEC: Air Conditioning and Refrigerating Equipment Part 5. As mentioned, traditional installations of a traction or hydraulic elevator include a separate machine room. The sump pump/drain shall have the capacity to remove a minimum of 11.4 m. 3 /h (3,000 gal/h) per elevator. Section 620.37 re-emphasizes that only wiring used in connection with the elevator is permitted within the hoistway, machine room, control room/machinery space or control space. All of these options and special wiring can be challenging depending upon the location of the shunt trip circuit breaker as well as who has responsibility for providing these additional options.