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As always, the best advice in all instancesdo your homework, communicate often, and document decisions made. 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. Later in the 19th century, Thomas Edison and his associates built an electrical distribution system in Lower Manhattan.
Eazylift Albany LLC, 836 Troy Schenectady Rd, Latham, NY, Elevators He had been with Eaton (Cutler-Hammer and Bussmann) since 1993 and specializes in training on the design and application of overcurrent protective devices and equipment in electrical distribution systems in accordance with the National Electrical Code and equipment in accordance with the various product standards. [emailprotected] After reading this article, you should have learned about: The meanings of definitions for control room and control space versus machine room The purpose and specifications for working spaces Insulation types and minimum sizes of conductors Requirements for feeder and branch-circuit conductors Feeder demand factors for ele-vators. The reason the NEC CMP 12 added these requirements, as shown in the panel statements, directly relates to the concern that elevator controllers can be installed in locations where the available fault current can be high and the inspector may not be able to clearly determine the SCCR of the elevator controller unless it is marked on the equipment. Also located in this room might be, but not limited to: exhaust fan, cooling unit (depending on local requirements and/or requirements set forth by the individual elevator supplier), lighting, voice and/or data drop serving the elevator cab emergency phone, elevator controller primary fused disconnect, elevator feeder shunt-trip circuit (i.e., shunt-trip circuit breaker), elevator cab lighting fused switch, and convenience receptacle(s). These 29 CFR 1910.146 (c) (8) requirements are: q!^mDtsnEX3_ shvqu+X9@w3gSj`g 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. 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. (e) Pit Maintenance. Dec. 21, 2010. The cover shall be secured and level with the pit floor. ), advise the building owner to correct the condition. NFPA 72 requires the control circuit between the Fire Alarm System and the shunt trip be monitored for integrity. This requirement applies to all controllers, disconnecting means and other electrical equipment that may need servicing, inspection or maintenance. 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. Louisiana State Uniform Construction Code Council adopts the 2014 NEC, Basic three-phase power measurements explained, Safety After the Storm Operating Portable Generators. This may include wiring for signals, communication with the car, lighting, heating, air-conditioning and ventilation of the car or hoistway for fire-detecting systems and pit sump pumps. The drain or sump pump discharge shall be into the sanitary or storm drainage system through an indirect waste connection. Building codes were deemed necessary to protect the public against shoddy builders and outmoded construction techniques. But, building codes had been in existence for many centuries. : inspecting; troubleshooting; observing; etc.) The same figure applies to nonmetallic wireways. 1993 NEC 15-20 Amp 120 volt Receptacle Requirements: Wet bar sinks, all bathrooms, roof tops, elevator machines rooms, elevator car tops, elevator pits. -inch conduit is needed to the sump pump. Traction elevators are typically faster and more energy efficient than hydraulic elevators, and are often used for high-rise buildings. 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. In hoistways not longer than 6 ft., these additional wiring methods are permitted: A sump or oil-recovery pump located in the pit is permitted to be cord connected. We resume with a look at wiring methods, overcurrent protection, grounding and other NEC provisions as they relate to these installations. 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. Lights and convenience outlets in elevator pits shall be installed to comply with the requirements of CCR, Title 24, Part 3, Article 620. Hydraulic reservoir characteristic of a hydraulic-piston-operated elevator. Sign up for our free e-newsletter. 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.
GFCIs in Elevator Pits, Receptacles and More 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. Furthermore, at least one 125-V, single-phase, 15- or 20-amp duplex receptacle is to be provided in each machine room or similar location. Motors for traction elevators were traditionally DC or synchronous, but new installations use AC motors and VFDs for speed control. (ASME has a separate document, A18.1-2008 Safety Standard for Platform Lifts and Stairway Lifts). It does specify wiring methods allowed, though, in 620. Mobile, AL 36606 USA (To design and install an elevator for a Class I, Division 1 location would be quite an undertaking.). A section on branch circuits for car lighting, receptacles, ventilation, heating and air-conditioning contains a number of important provisions. Corporate Office ^W i word/document.xml=nr]6Id=,_$j9-"Y.iGU\h_}. My reasoning comes from 620.24 (A) and (C).
PDF Compliance with the 2017 NEC for Elevator Controllers 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. 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. Feeders may be installed within the hoistway where the elevator has a driving-machine motor in the hoistway or on the car or counterweight. 836 Troy Schenectady Road Latham, NY 12110 . 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. NEC 2011 also addresses branch circuits for machine room or control room/machinery space or control-space lighting and receptacles. Mike Holt. All Rights Reserved | Contact Us | Privacy Policy. +90 (216) 348 4876, India Office Elevator power disconnect (with utility feed marking) located in the machine room or other permitted location. Guarding: Where possible, install temporary guarding to protect from inadvertent contact. 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. The architect has a choice of either traction or hydraulic elevators. Limit switches placed throughout the height of the shaft communicate with the controller and stop the cab at each landing. The basic idea is that there must be a separate, dedicated circuit for car lights, receptacles and ventilation on each car. 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. Pit light with guard (ten foot candles min. Design practices that are acceptable in some jurisdictions may not be in others. 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. 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). Based on the analysis, the arc-flash boundaries at the elevator/escalator controllers ranged from 3-16 in. Hydraulic elevators comprise a hydraulic reservoir, pump, cylinder, and controller. Another location that requires a separate branch circuit for lighting and receptacle(s) is the hoistway pit. A different occurrence involves exposure to the explosive blast when there is a line-to-line or line-to-ground arc blast. 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). 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. Another important electrical system design consideration for supplying power to multiple elevators is NEC 620.62. As we have seen, a limited number of these are approved for elevator locations car, hoistway, pit and machine room. 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. 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. Many NEC articles address voltage limitations, and Article 620 is no exception. NEC specifies Hoistway wiring, and doesn't seem to distinguish between hoistway and pit. The traveling cable, of necessity, is exempted. This room is to be secured against unauthorized access (kept locked). 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. Elevator cab lights require emergency back-up power. I've never run into this before. 953 0 obj
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Otherwise, specify that the elevator supplier provide a battery back-up unit to power the lights in the event of an outage. The AHJ is saying that this is a violation of 620.23. +91 8025357028, 2022 Elevator World, LLC. Additionally, ampacities of the individual conductors and flame-retardant properties of the overall cable are important factors. It need not be exactly centered on the equipment, and working spaces of adjacent pieces of equipment may overlap. Hazards created by water, snow or condensation in the work area can cause slips, falls and accidental contact. This is somewhat broader than A17.1-2007/B44-07. 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. 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. Apr 24, 2013. correct me if I'm wrong, but I believe it's damp. Your IP: z, /|f\Z?6!Y_o]A PK ! You must run a separate insulated grounding conductor with the feeder conductors from the electrical source to the elevator controller. Overload protection for motors is to conform with Article 430, Part III, the general code area that covers motor and branch-circuit overload protection for all motors. The conduit alone can't act as the grounding means. 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.
NEC Guidelines on Commercial Garages | EC&M (A) Separate Branch Circuit. 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. The branch circuit is to be protected by an overcurrent device located in the machine room, control room/machinery space or control space. 23.254.250.15 Any other utilization equipment associated with the elevator The code notes that elevator rails or other hoistway equipment are not to be used as the grounding conductor for lightning-protection systems. 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 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. The main concern is to ensure that workers may escape to safety in the awful circumstance of an arc-fault event. Every building is different. A traction elevator's equipment room is typically located at the top of the building, directly over or adjacent to the shaft. !>x=yy Bvv8?~e PK ! 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. It is further specified the machine-room lighting switch be located at the point of entry. 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?
A separate branch circuit shall supply the hoistway pit lighting and receptacle (s). GFI Receptacles: GFI receptacles shall be required in all elevator machine rooms, machinery spaces and elevator pit areas. 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. In the event of a breakdown, that phone must automatically call a location staffed 24 hours a day. Something went wrong. It employs specialists in Mobile, Alabama, and has technical and news correspondents around the world. The light switch for the equipment room must be adjacent to the entrance door on the latch side. This may be countered by providing good machine-room ventilation. But by understanding how these items fit together and what purpose they serve, you can have a successful project. 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. Please check your entries and try again. NEC Article 620 Part VI, Disconnecting Means and Control, is rather exacting. 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. In addition, the shunt-trip voltage must also be monitored by the Fire Alarm System. 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. As they review the plans and the construction site, they may have conflicting interpretations or requirements. They are to be part of listed equipment, a driving machine or a driving-machine brake. ) > 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 We generally think of the 19th century as the great age of building codes. 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. 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. 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. Sumps and sump pumps in pits, where provided, shall be covered. or larger, not over 6 ft. in length. Always verify all conditions and requirements with the state and the AHJ where the installation is taking place. Similar provisions are attached to elevator-car heating and air-conditioning disconnecting means, and to other utilization equipment. In case of emergency, electricians, maintenance personnel and any elevator technicians called in to the premises should have ready access to the key. 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. 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. The code is not concerned with the efficiency or sophistication of equipment that it covers, except insofar as safety (in terms of human injury and property damage) is concerned. 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. 354 Morgan Ave. Similarly, motor branch-circuit short circuit and ground-fault protection must be as required in Article 430, Part IV, for all motors. 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). A single dedicated receptacle supplying a permanently installed sump pump does not have to be a GFCI type. 988 0 obj
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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. 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. You are seeing this message for one of three reasons: You have reached your limit of free content. When you're designing an electrical system for a building, don't let elevator requirements bring you down. Where voltages exceed 600, a sign reading DANGER HIGH VOLTAGE is required. Get more of Elevator World. NEC Article 0: Elevator art by David Herres Continued. from components that are not otherwise guarded. NEC Article 620 contains numerous other disconnect provisions, which must be carefully scrutinized prior to design work so the installation is compliant. It states an elevator is permitted to be run by an emergency or standby power system. As stated in Section 7 of the Elevator Industry Field Employees Safety Handbook: Unless it is not feasible, (i.e. Traction elevators are typically installed in a bank of elevators where fused switches, or circuit breakers in a panelboard are located in the machine room serving the bank of elevators. Article 620 follows this pattern by opening, in Section I, General, with a statement of scope and definitions applicable to the topic under consideration. It is further stipulated that internal voltages of power-conversion equipment and functionally associated equipment, and the operating voltages of wiring interconnecting the equipment, are permitted to be higher, provided that the equipment and wiring are listed for the higher voltages. Additional requirements concern escape routes. For example, an inadequately supported ceiling fan could fall and cause injury or property damage. These may include: The author would like to recognize Jonathan Kennedy for his assistance in creating this article. It is stated that traveling cables are to be suspended at the car and hoistway ends, or counterweight end where applicable, so as to reduce the strain on the individual copper conductors to a minimum. The sump pump/drain shall have the capacity to remove a minimum of 11.4 m. 3 /h (3,000 gal/h) per elevator. The pump sends hydraulic fluid from the reservoir to the cylinder, buried deep below the elevator shaft. 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). It is worth noting that these NEC terms, used throughout Article 620, have been chosen to correlate with A17.1-2007 usage. The feeder OCPD needs to remain closed so the remaining elevators have power and continue to function. However, when I've put in elevators, NEC seems to always take a back seat to ANSI, which seems . Other requirements: Spa's and Hot Tubs 1996 NEC 15-20 Amp 120 volt Receptacle Requirements for Dwelling units: All outdoor Acceptable types of wire for this application are given in Table 400.4, which occurs in an earlier chapter and lists various types of elevator cable for lighting and control in both unclassified and hazardous locations. above the seal plate, adjacent to the ladder. Be sure to provide a horn/strobe alarm in large equipment rooms because they can be noisy, isolated places. But the lights don't have to be in the pit itself. A single means for disconnecting all ungrounded main power-supply conductors is required and must be designed so no pole can be operated independently. 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.
Inspecting Elevator Power Wiring - IAEI Magazine To achieve flexibility and endurance, traveling cable is more finely stranded and, where possible, separated into discrete conductors. Firefighters can then use portable telephone handsets in combination with the jacks and cabling. 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. ,l7CLHmcX9*F -{Q|^"XL`b1y]$,y *R/2Rn{\xG
L*vMP.uKW,)68]Y}+ FYS1B=Q0S>Hc IAEI News Magazine. Conductors supplying a single motor controller are to have an ampacity not less than the motor controller nameplate current rating plus all other connected loads. Three wiring categories within hoistways are allowed in addition, each with exceptions. 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. For platform lifts and stairway chairlifts, the duty is intermittent. 1. Accordingly, the supply wires are protected only for short circuit, and the overload protection is provided closer to the motor. 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.
PDF Elevator Safety Program - Technical Clarification These are: remote machine room and control room (for elevator and dumbwaiter), and remote machinery space and control space (for elevator and dumbwaiter). 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. This is not the elevator companys responsibility. Many of these are for portable lighting.). A second door is required if the equipment is rated over 1200 amps and over 6 ft. wide. Even non-composite fiber-optic cable, which does not carry electrical energy, is subject to the code. Society of Mechanical Engineers. Where necessary, it is mandated that suitable guards be provided to protect the cables against damage. [emailprotected] Get more of Elevator World. 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. For current-limiting fuses, the information to achieve selective coordination has been available for many years in fuse amp ratio tabular form.