N _rels/.rels ( j0@QN/c[ILj]aGzsFu]U ^[x 1xpf#I)Y*Di")c$qU~31jH[{=E~ %%EOF We generally think of the 19th century as the great age of building codes. Loss of voltage to the control circuit for the disconnecting means shall cause a supervisory signal to be indicated at the control unit and required remote annunciation. But the lights don't have to be in the pit itself. No provision is to be made to automatically restore power. The locking capability is important so during maintenance, the equipment will not be inadvertently energized. The reason the NEC CMP 12 added these requirements, as shown in the panel statements, directly relates to the concern that elevator controllers can be installed in locations where the available fault current can be high and the inspector may not be able to clearly determine the SCCR of the elevator controller unless it is marked on the equipment. IAEI News Magazine. Where a feeder powers more than one elevator, you need selective coordination; the OCPDs must be series-designed so a fault at one of the elevators will be cleared by only the OCPD serving it. Beginning with Article 320, Armored Cable (Type AC) and concluding with Article 398, Open Wiring on Insulators, each code-sanctioned cable and raceway is treated, ranging from the familiar Type NM (trade name Romex) to the exotic Integrated Gas Spacer Cable (Type IGS). (B) Lighting Switch. These selective coordination tables for current-limiting fuses show the minimum amp ratio required between a pair of fuses of a given type(s) to achieve selective coordination. h-`7 ) > word/_rels/document.xml.rels ( N0HC;qRN/W$#{1EM]ZY|vj5h),-g!`./V/KKFY4D#la&V#=$Q7|l/d#hS 7+IDZ!J 6KucD^s`+>=(3E These are covered for generic, non-elevator specific use in earlier articles, 376 and 378, in Chapter 3, Wiring Methods and Materials. The same figure applies to nonmetallic wireways. 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. Part X, Emergency and Standby Power Systems, is simple and straightforward. 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. It employs specialists in Mobile, Alabama, and has technical and news correspondents around the world. f?3-]T2j),l0/%b If you can illuminate the pit using lights that are "above the top of the pit" (whatever that . In this case, it may be best if the elevator controller manufacturer does not include the elevator disconnecting means (often offered as a circuit breaker) but instead have the installer provide a separate fused disconnect to comply with NEC 620.51(A) and also achieve a high SCCR for the elevator controller when fuses are provided as specified by the elevator controller and marked on the elevator controller nameplate. (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. 988 0 obj <>stream The fan should be on a dedicated circuit. (f) Illumination of Pits. 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. 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. Electricity is often one of the initial services to fail during a storm. Moreover, because motors have a higher starting current than other loads, the overcurrent protection protocol is unique to them and somewhat counterintuitive. With heavy use on a hot day, the oil can overheat, causing elevator shutdown. If elevators are supplied by the emergency, legally required standby or critical operation power systems, then selective coordination is required per the 2017 NEC in 700.32, 701.27 or 708.54. He also required GFCI protection for the hard-wired sump pump that did not require it. Even non-composite fiber-optic cable, which does not carry electrical energy, is subject to the code. The idea is quite simple. +;-mka|7! The main impetus for the creation of the NEC in the closing years of the 19th century was the collective anguish experienced by insurance underwriters who were losing vast amounts of money due to liability and physical damage claims resulting from Edisons electrification of, first, Lower Manhattan and then the world. The light switch for the equipment room must be adjacent to the entrance door on the latch side. 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). 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. Personal protective equipment (PPE): Use appropriate PPE to protect body parts within the range of 3-16 in. 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). These conductors may be covered with suitable shielding for telephone, audio, video or higher-frequency communications circuits. NEC specifies Hoistway wiring, and doesn't seem to distinguish between hoistway and pit. 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. 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. The two primary hazards are fire and electric shock or arc flash, although there are others. When you're designing an electrical system for a building, don't let elevator requirements bring you down. There are options available to achieve this depending upon the customers needs. 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. 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. 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. We have circuited the receptacles and lights in the pits to the same circuit. For this reason, the NEC provides for adequate working space around electrical equipment that may need to be serviced. The light switch shall be located so to be accessible from pit access door. In addition, the shunt-trip voltage must also be monitored by the Fire Alarm System. Described below are several work practices that may be used to reduce arc-flash hazards when working on energized equipment: 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. 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. wide or the width of the equipment, whichever is greater. Article 620s Definitions section includes two terms that describe spaces not attached to the outside of a hoistway. !>x=yy Bvv8?~e PK ! 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. This is typically accomplished via a shunt trip device. You need to Subscribe to continuing reading. 953 0 obj <> endobj The feeder OCPD needs to remain closed so the remaining elevators have power and continue to function. above the seal plate, adjacent to the ladder. Finally, typical installations and compliance with all these requirements will be discussed. Such cable groups are to be supported at intervals not over 3 ft. and located so as to be protected from physical damage. 2m9 `K]f*F gaR Additionally, ampacities of the individual conductors and flame-retardant properties of the overall cable are important factors. Marking the available short-circuit (fault) current on the controller by the equipment installer. Instruments: Use category III multimeters and be familiar with their use and limitations. Many NEC articles address voltage limitations, and Article 620 is no exception. 68 | WWW.ELEVATORWORLD.COM | June 2012 Continuing Education . 836 Troy Schenectady Road ; Latham, NY 12110 . The party responsible for procuring the elevator control panel must state the minimum acceptable SCCR or the maximum available fault current where the controller will be installed. 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) First, it is now clear that elevator controllers must be marked by the manufacturer with their SCCR. 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. Machine room/control space lighting and receptacles 4. One. The conductors must be in their original sheaths or grouped together and taped or corded. 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. 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. Society of Mechanical Engineers. 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. 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. Adhering to the requirements will ensure a hazard-free electrical installation. 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. 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. For instance, one method to reduce the available fault current is to add an isolation transformer ahead of the elevator controller. Because they need to move and flex, traveling cables are not required to be in a raceway. 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. %PDF-1.5 % 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. 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. 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. It is important to note, that these selective coordination tables can indicate a lack of selective coordination at a given fault current for circuit breakers that do not show overlap on the time-current curves of the circuit breakers. However, this can vary depending on building conditions and exterior grade. 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. But, building codes had been in existence for many centuries. Weight (passengers, freight, car and attendant machinery) may be fairly substantial, and speed is significant. (All intentionally grounded elements must be held at equal potential.) Second, it must be configured so as to eliminate any chance of tangling or chafing against the inner surface of the hoistway or items mounted on it. (C) Duplex Receptacle. As they review the plans and the construction site, they may have conflicting interpretations or requirements. Hazards created by water, snow or condensation in the work area can cause slips, falls and accidental contact. 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. Years may lapse between the design and installation stages of a project. The thinking behind this requirement is that the injured worker could have severe hand burns and be unable to operate a conventional doorknob. Apr 24, 2013. correct me if I'm wrong, but I believe it's damp. Many undertake trips in these devices two or more times daily in full confidence that they will survive an uneventful experience with a minute chance of disaster or even inconvenience. Limit switches placed throughout the height of the shaft communicate with the controller and stop the cab at each landing. Notice the definition mentions the full range of operating times. The action you just performed triggered the security solution. If the disconnecting means is an integral part of the motor controller, it is to be operable without requiring opening of the enclosure. As mentioned, traditional installations of a traction or hydraulic elevator include a separate machine room. Each of these performs a different function, and the wiring mandates vary accordingly. ASME A17.1 . The disconnecting means is to be located adjacent to or an integral part of the motor controller. The pump sends hydraulic fluid from the reservoir to the cylinder, buried deep below the elevator shaft. 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. 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. 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. You are seeing this message for one of three reasons: You have reached your limit of free content. So, we see that for elevator work, greater fill is allowed. 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. It begins by considering metal and nonmetallic wireways. Louisiana State Uniform Construction Code Council adopts the 2014 NEC, Basic three-phase power measurements explained, Safety After the Storm Operating Portable Generators. 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. They are to be part of listed equipment, a driving machine or a driving-machine brake. Choose topics from a full list of courses covering electrical topics that cover what you need to know from the NEC and other electrical codes and standards. The main concern is to ensure that workers may escape to safety in the awful circumstance of an arc-fault event. Car lighting, receptacles and ventilation 2. They are permitted to be run without raceway when used inside the hoistway, on the elevator car, hoistway wall, counterweight, or controllers and machinery located inside the hoistway, provided they are in their original sheaths. 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. It is worth noting that these NEC terms, used throughout Article 620, have been chosen to correlate with A17.1-2007 usage. Pit light with guard (ten foot candles min. The traveling cable, of necessity, is exempted. 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. 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. A single dedicated receptacle supplying a permanently installed sump pump does not have to be a GFCI type. 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. 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. Motors for traction elevators were traditionally DC or synchronous, but new installations use AC motors and VFDs for speed control. Here, the National Electrical Safety Code has jurisdiction. Flexible cords and cables (same conditions as within hoistways). 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. Every building is different. Hard-service cords are permitted only as flexible connections for the top-of-car operating device or the car-top work light. +91 8025357028, 2022 Elevator World, LLC. Pits shall be maintained in a clean and dry condition. 354 Morgan Ave. 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. ^W i word/document.xml=nr]6Id=,_$j9-"Y.iGU\h_}. Corporate Office : inspecting; troubleshooting; observing; etc.) (A) tells us that the lighting and receptacle (s) for the pit must be on separate circuits. Fluid pressure in the cylinder raises and lowers the elevator cab. 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. Cylinders in hydraulic elevators usually aren't suitable for buildings taller than five stories. 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. The architect has a choice of either traction or hydraulic elevators. On existing or listed equipment, conductors are permitted to be grouped together and taped or corded without being installed in a raceway. Part of the reason that elevator usage is extraordinarily safe is that construction and maintenance are regulated by the wonderfully robust ASME A17.1 2007/CSA B44-07 Safety Code for Elevators and Escalators, which contains overall construction and maintenance requirements everything from seismic mandates to machine-room lighting. 354 Morgan Ave. 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. NEC Article 620 Part VI, Disconnecting Means and Control, is rather exacting. 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. The lighting switch shall be located so as to be readily accessible from the pit access door. +90 (216) 348 4876, India Office Another important electrical system design consideration for supplying power to multiple elevators is NEC 620.62. These 29 CFR 1910.146 (c) (8) requirements are: Elevator motors are inherently intermittent duty. 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. Of particular importance is the location of the disconnecting means so it can be found by an individual who may not be familiar with the installation. 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. 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. 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. It states an elevator is permitted to be run by an emergency or standby power system. Related Code Sections 802.1.8 Indirect/Special Waste, Elevator Pit Drain or Sump Pump or larger, not over 6 ft. in length. An exception provides that liquid-tight flexible metal conduit or liquid-tight flexible nonmetallic conduit 3/8 in. Jul 15, 2021. 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). Any other utilization equipment associated with the elevator The cord is to be a hard-usage, oil-resistant type not over 6 ft. in length. In driving through commercialized suburban areas, you frequently see paralleled conductors for large retail grocers (where there is a heavy refrigeration load). 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. For all of this to come together in the real world, there had to be some assurance that these new technologies could be used safely on a wide scale. This is somewhat broader than A17.1-2007/B44-07. Get more of Elevator World. Part III, Wiring, looks at the types of wiring that may be installed in hoistways, cars, machine rooms and related spaces. In contrast to the lighting, these receptacles must be connected to GFCI devices. The fire loading resulting from an accumulation of abandoned low-voltage cabling may be considerable, and has to be understood and dealt with. The cover shall be secured and level with the pit floor. +90 (216) 348 4876, India Office 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. 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. Always verify all conditions and requirements with the state and the AHJ where the installation is taking place. The simplest option is to use a shunt trip circuit breaker in either the feeder supplying the elevator or the elevator disconnect. As we have seen, a limited number of these are approved for elevator locations car, hoistway, pit and machine room. Requirements in Article 620 modify the articles in Chapter 3. 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. [emailprotected] This room is to be secured against unauthorized access (kept locked).
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