PDF C.1 General Requirements for All Elevator Installations Guidance in determining whether elevator pits meet the definition of But the lights don't have to be in the pit itself. 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. 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. 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). All Rights Reserved | Contact Us | Privacy Policy. You are seeing this message for one of three reasons: You have reached your limit of free content. However, this can vary depending on building conditions and exterior grade. 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, 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. This is because the material may contribute fuel to a fire that has originated elsewhere. Additionally, ampacities of the individual conductors and flame-retardant properties of the overall cable are important factors. The circuit(s) for the lighting and receptacles must be dedicated to the elevator area only. 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. The electrical system designer calculates the maximum available fault current at the elevator controller. Cross-sectional areas of wireways are found by multiplying the two interior dimensions.) The usual scenario for electrical injury is shock when electrical current passes through the human body. above the pit floor, shall: Be weatherproof (NEMA 4). (e) Pit Maintenance. For platform lifts and stairway chairlifts, the duty is intermittent. You are a subscriber that needs to Sign In. Overcurrent devices protecting these branch circuits are to be located in the machine room or similar location. Part II of Article 620 concerns conductors used in elevator work, and several important requirements are covered. z, /|f\Z?6!Y_o]A PK ! Many NEC articles address voltage limitations, and Article 620 is no exception. 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. To avoid this situation, designers can specify elevator controls with a safety feature commonly called a rescuvator. Each fused switch or circuit breaker in the panelboard is used as an elevator disconnect. If the building has emergency power available, use it to supply the cab lights. 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. +;-mka|7! Instruments: Use category III multimeters and be familiar with their use and limitations. 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. 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.. If power is not being supplied to the elevator controller (e.g., open mainline fuses, etc. PDF Elevator Safety Program - Technical Clarification A further requirement concerns elevator-car air-conditioning and heating. 68 | WWW.ELEVATORWORLD.COM | June 2012 Continuing Education . 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. 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. A single dedicated receptacle supplying a permanently installed sump pump does not have to be a GFCI type. Granle is a licensed professional engineer with Sebesta Blomberg & Associates, Rochester, Minn. https://www.facebook.com/ElectricalConstructionMaintenanceMagazine, https://www.linkedin.com/company/electrical-construction-maintenance/, ABCs Construction Backlog Indicator Down to Start 2023, The Most Popular Code Quizzes of the Week from 2021, The 10 Most Popular Photo Galleries of 2021, Whats Wrong Here? APPENDIX A 2.2. 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. Receptacle for pumps located in the pit shall be a single non-GFCI and shall be located 6 inches above the lowest landing. 354 Morgan Ave. These must also be insulated for the maximum voltage applied to any conductor within the cable or raceway system. 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. 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. Heating and air-conditioning equipment located on the car must not be in excess of 600 V. All live parts of electrical apparatuses are to be enclosed to protect workers and the public against accidental contact. Because they need to move and flex, traveling cables are not required to be in a raceway. charlie b. 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. Traditionally, the electrical system design engineer has given little attention to the elevator controller. 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. IAEI News Magazine. Section 620.62, Selective Coordination, is central to multi-elevator installations and must be closely observed. (All intentionally grounded elements must be held at equal potential.) The basic idea is that there must be a separate, dedicated circuit for car lights, receptacles and ventilation on each car. 3016. Pits for Elevators. - California Department of Industrial Relations Marking the available short-circuit (fault) current on the controller by the equipment installer. The sump pump/drain shall have the capacity to remove a minimum of 11.4 m. 3 /h (3,000 gal/h) per elevator. By subscribing, you agree to our User Agreement and Privacy Policy & Cookie Statement. Cloudflare Ray ID: 7a2fbe9ebd7e2fe8 953 0 obj
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Cylinders in hydraulic elevators usually aren't suitable for buildings taller than five stories. 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. . A separate branch circuit shall supply the hoistway pit lighting and receptacle (s). 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. You'll need to run telephone cables to the equipment room control panel, but the elevator supplier will take care of getting the cables to the elevator cab. In contrast to the lighting, these receptacles must be connected to GFCI devices. 2m9 `K]f*F gaR
Cross-sectional areas of conduits are given in Chapter 9, Table 4. The fan should be on a dedicated circuit. Similar provisions are attached to elevator-car heating and air-conditioning disconnecting means, and to other utilization equipment. 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 circuit breaker selective coordination tables can be used to identify the maximum fault current that a pair of circuit breakers can selectively coordinate. 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. 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. A section on branch circuits for car lighting, receptacles, ventilation, heating and air-conditioning contains a number of important provisions. Section 620.85, GFCI Protection for Personnel, provides that 125-V, single-phase, 15- and 20-amp receptacles installed in pits, hoistways, machinery spaces, machine rooms, escalators and moving walks, and on elevator car tops are to be GFCIs. Hydraulic elevators comprise a hydraulic reservoir, pump, cylinder, and controller. Society of Mechanical Engineers. 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. Always verify all conditions and requirements with the state and the AHJ where the installation is taking place. The proposals resulted in adding new requirements in the 2017 NEC for: This article will also discuss other Code requirements that include selective coordination for elevators that are supplied by emergency, legally required standby or critical operation power systems or multiple elevators supplied from a single feeder, and shunt tripping of elevators where the elevator equipment room and/or shaft has a fire suppression sprinkler system. The conduit alone can't act as the grounding means. 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. The traveling cable, of necessity, is exempted. 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. CLAIMED . Where necessary, it is mandated that suitable guards be provided to protect the cables against damage. Selective coordination is also required for multiple elevators per NEC 620.62. f?3-]T2j),l0/%b Other terms defined in NEC Article 620 are Control System, Motion Controller, Motor Controller, Operation Controller, Operating Device and Signal Device. 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. Frequently Encountered Items That Delay Accep Tance of New Elevators The lighting is not to be connected to a GFCI, because the elevator car is not a place that should experience nuisance tripping. (Cross-sectional areas of conductors are given in Chapter 9, Tables 5 through 8. 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. Your Quick and Easy Elevator Code Checklist | Kings III of the sprinkler heads. First, it is now clear that elevator controllers must be marked by the manufacturer with their SCCR. Elevator motors are inherently intermittent duty. 23.254.250.15 The architect has a choice of either traction or hydraulic elevators. Marking the elevator controller short-circuit current rating (SCCR) by the elevator controller manufacturer. Elevator PITS | Mike Holt's Forum These are part of Article 725, Class 1, Class 2 and Class 3 Remote-Control, Signaling, and Power-Limited Circuits. [emailprotected] Similarly, motor branch-circuit short circuit and ground-fault protection must be as required in Article 430, Part IV, for all motors. By subscribing, you agree to our User Agreement and Privacy Policy & Cookie Statement. 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 generally think of the 19th century as the great age of building codes. 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. This is especially true in an elevator shaft where measures have to be taken to ensure that a hazardous situation is not created. The cord is to be a hard-usage, oil-resistant type not over 6 ft. in length. If the disconnecting means is an integral part of the motor controller, it is to be operable without requiring opening of the enclosure. ,l7CLHmcX9*F -{Q|^"XL`b1y]$,y *R/2Rn{\xG
L*vMP.uKW,)68]Y}+ FYS1B=Q0S>Hc Besides the initial determination requirement of paragraph (c) (1), the "host" employer must comply with the five (5) requirements of paragraph (c) (8) when engaging another employer (contractor) who will have employees in permit spaces under the control of the host employer. While machine room-less designs have been commercially available for many years, their use may still be unknown to some AHJs. Please check your entries and try again. Elevator travel is far safer than an automobile trip, and the chance of experiencing disaster is on the order of being struck by lightning in ones own backyard. Here again, the lighting is not to be connected to a GFCI, whereas such protection is required for the receptacle(s). As an installer and an inspector, one common issue I've seeen is incompatible connections associated with raceways connections and fittings. This switch will ensure that the elevator won't descend into the elevator pit and allow maintenance people to work safely in the area beneath the cab. Metallic articles: Remove metallic articles such as watches, chains, bracelets, earrings, belt buckles and keychains before troubleshooting. As we have seen, a limited number of these are approved for elevator locations car, hoistway, pit and machine room. 1993 NEC 15-20 Amp 120 volt Receptacle Requirements: Wet bar sinks, all bathrooms, roof tops, elevator machines rooms, elevator car tops, elevator pits. 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. +1-251-479-4514 | [emailprotected], Trkiye Office High-rise buildings pose additional concerns. 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. 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. Flexible metal, liquid-tight flexible metal or liquid-tight flexible nonmetallic conduit 3/8 in. To achieve flexibility and endurance, traveling cable is more finely stranded and, where possible, separated into discrete conductors. 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. David Herres . The branch circuit supplying these units is to be similarly dedicated, with the associated overcurrent device located in the machine room or similar location. Freight Elevator Door Control: An Opportunity for Wireless Technology. NEC Article 620 Part V, Traveling Cables, is driven by two major issues. Hydraulic elevators are typically more cost effective and used for buildings up to 5-6 stories. Performance & security by Cloudflare. Traditional wiring methods and materials come into play, as always, but it is necessary to rethink their deployment. For circuit breakers, time-current curves must be consulted as well as the circuit breaker manufacturers selective coordination tables. 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. First, you'll need to install lighting in the elevator equipment room (Photo 1) and shaft pit (Photo 2). Please check your entries and try again. (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. 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. Weight (passengers, freight, car and attendant machinery) may be fairly substantial, and speed is significant. [emailprotected] 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. Any other utilization equipment associated with the elevator 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. from the exposed components, and the incident energy calculated at 18 in. Firefighters can then use portable telephone handsets in combination with the jacks and cabling. They are to be part of listed equipment, a driving machine or a driving-machine brake. 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. Traveling cables are to be approved for hazardous locations and must comply with the appropriate sections for each hazardous-location class that covers use of flexible cords. The light switch in the pit must be mounted 42 in. Hazards created by water, snow or condensation in the work area can cause slips, falls and accidental contact. 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)]. 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. The code notes that elevator rails or other hoistway equipment are not to be used as the grounding conductor for lightning-protection systems. Hint: Duct Tape to the Rescue, NEC: Air Conditioning and Refrigerating Equipment Part 5. Good documentation is of key importance to recalling what decisions were made and why. The code exempts some fairly broad areas where compliance is not expected. PDF Electric Elevator Checklist Cover Page - Oregon The disconnecting means must disconnect the elevator from the emergency, standby and normal power systems. The article stands apart from the rest of the code in the sense it exempts these categories of circuits from the general requirements for wiring in most occupancies, found in Chapter 3. Car air-conditioning and heating units 3. 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. NEC Guidelines on Commercial Garages. Design practices that are acceptable in some jurisdictions may not be in others. GET YOUR CEUS TODAY, 1998-2021. Be sure to provide a horn/strobe alarm in large equipment rooms because they can be noisy, isolated places. This, however, can result in a dramatic increase in cost, space availability (lack thereof), and reduced efficiency. 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. Three wiring categories within hoistways are allowed in addition, each with exceptions. ^W i word/document.xml=nr]6Id=,_$j9-"Y.iGU\h_}. But, building codes had been in existence for many centuries. 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. Such cable groups are to be supported at intervals not over 3 ft. and located so as to be protected from physical damage. Home Articles Elevator World June 2012 Issue NEC Article 620: Elevators, Part 2. Machine room/control space lighting and receptacles 4. NEC 620.62 requires the elevator disconnecting means (fused switch or circuit breaker) to selectively coordinate with all supply-side overcurrent devices. Flexible cords and cables (same conditions as within hoistways). If you can illuminate the pit using lights that are "above the top of the pit" (whatever that . 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. This equipment is restricted to that used in connection with the specific elevator, dumbwaiter, escalator, moving walk, platform lift or stairway chairlift. Through numerous editions, the NEC has, to a great extent, mitigated the hazards accompanying widespread use of electricity, particularly with respect to elevator technology. 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. q!^mDtsnEX3_ shvqu+X9@w3gSj`g 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. Based on the analysis, the arc-flash boundaries at the elevator/escalator controllers ranged from 3-16 in. 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. The locking capability is important so during maintenance, the equipment will not be inadvertently energized. The Electrical Ups and Downs of Elevator Design | EC&M This lighting and receptacle circuit is separate from the circuit serving the motor. Nevertheless, the primary NEC focus is on elevators, and the intention is to mitigate the hazards associated with the use of electricity. 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. Supports for cables or raceways in a hoistway or in an escalator or moving-walk wellway or platform lift and stairway chairlift runway must be securely fastened to the guide rail, escalator or moving-walk truss, or to the hoistway, wellway or runway construction.
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