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An example would be the elevator, as well as all wiring in a utility-owned administration building. 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. or larger, not over 6 ft. in length. With heavy use on a hot day, the oil can overheat, causing elevator shutdown. 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. The next section, 620.36, concerns different systems in one raceway or traveling cable. Cloudflare Ray ID: 7a2fbe9ebd7e2fe8 Flexible metal, liquid-tight flexible metal or liquid-tight flexible nonmetallic conduit 3/8 in. . NEC Article 620 Part V, Traveling Cables, is driven by two major issues. NEC has a further note that the term wheelchair lift has been changed to platform lift.. Part III, Wiring, looks at the types of wiring that may be installed in hoistways, cars, machine rooms and related spaces. This, however, can result in a dramatic increase in cost, space availability (lack thereof), and reduced efficiency. 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. In the event of a breakdown, that phone must automatically call a location staffed 24 hours a day. APPENDIX A 2.2. Each fused switch or circuit breaker in the panelboard is used as an elevator disconnect. This equipment is restricted to that used in connection with the specific elevator, dumbwaiter, escalator, moving walk, platform lift or stairway chairlift. Article 620s Definitions section includes two terms that describe spaces not attached to the outside of a hoistway. Another location that requires a separate branch circuit for lighting and receptacle(s) is the hoistway pit. 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. Be sure to provide a horn/strobe alarm in large equipment rooms because they can be noisy, isolated places. 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 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 power disconnect (with utility feed marking) located in the machine room or other permitted location. Many professionals believe the NEC is applicable only for voltages over a certain level, but that is not the case. As such, elevator controller manufacturers should make the effort to rethink their designs to avoid costly system design changes. Adhering to the requirements will ensure a hazard-free electrical installation. As we have seen, a limited number of these are approved for elevator locations car, hoistway, pit and machine room. Many NEC articles address voltage limitations, and Article 620 is no exception. 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. Building codes were deemed necessary to protect the public against shoddy builders and outmoded construction techniques. 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. 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. The locking capability is important so during maintenance, the equipment will not be inadvertently energized. Modern electronic elevator controls can be sensitive to temperature shifts. Hydraulic elevators are typically more cost effective and used for buildings up to 5-6 stories. 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. These 29 CFR 1910.146 (c) (8) requirements are: charlie b. , !! ASME A17.1, Section 2.2.5, National Electrical Code, Rule 620-85 4. f?3-]T2j),l0/%b 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. Through numerous editions, the NEC has, to a great extent, mitigated the hazards accompanying widespread use of electricity, particularly with respect to elevator technology. Sumps and sump pumps in pits, where provided, shall be covered. The pump sends hydraulic fluid from the reservoir to the cylinder, buried deep below the elevator shaft. Even though Edison grasped the basic ideas of fusing and overcurrent protection, many hazards remained. 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. Nevertheless, the primary NEC focus is on elevators, and the intention is to mitigate the hazards associated with the use of electricity. Upon loss of power, the rescuvator controls the cab, lowers it to the designated floor, and opens its doors. 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.. (g) Stop Switch in Pits. 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. 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. 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. (A) tells us that the lighting and receptacle (s) for the pit must be on separate circuits. Follow the manufacturers instructions and precautions. Many new buildings are incorporating an elevator design that does not include an equipment room (sometimes called machine room-less elevators). PK ! Here, the National Electrical Safety Code has jurisdiction. Dan Neeser is a Senior Field Application Engineer with Eatons Bussmann Division. 0 4.0 (2 Reviews) (2) CLAIMED . NFPA 72 requires the control circuit between the Fire Alarm System and the shunt trip be monitored for integrity. By subscribing, you agree to our User Agreement and Privacy Policy & Cookie Statement. The feeder OCPD needs to remain closed so the remaining elevators have power and continue to function. Traveling cables are to be supported by one of these means: Looping the cables around supports for unsupported lengths less than 100 ft. The elevator pit discharge system is not required to include an oil separator, except as required by section 1003.4. 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. A few years later, in 1880, Werner von Siemens built the first electric elevator, setting the stage for a new industry that would change the world by making the practical use of tall buildings possible. Mike Holt. First, it is now clear that elevator controllers must be marked by the manufacturer with their SCCR. If we fast forward more than 36 centuries, we see some important new developments in elevator technology. If the equipment must remain energized to perform work, effective insulation and safe electrical working practices should be observed. From the website: Mohawk Lifts offers car lifts and auto lifts for purchase, including 2 post lifts, 4 post lifts, storage lifts, heavy duty mobile column lifts, parallelogram lifts, and other specialty items. Selective coordination is defined by the NEC as: Localization of an overcurrent condition to restrict outages to the circuit or equipment affected, accomplished by the selection and installation of overcurrent protective devices and their ratings or settings for the full range of available overcurrents, from overload to the maximum available fault current, and for the full range of overcurrent protective device opening times associated with those overcurrents.. Overcurrent devices protecting these branch circuits are to be located in the machine room or similar location. It is further stated that the disconnecting means are not to disconnect the branch circuits required in sections 620.22, 620.23 and 620.24. 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. You need at least one 120VAC GFCI-protected receptacle at each location. 2.2.6.1 This switch shall be so located as to be acces-sible from the pit access door. z!0: - [Content_Types].xml ( n0EUb*>-RxV=QUAl"93dFk%Y?l}MGDV Society of Mechanical Engineers. Recommendations for EazyLift Elevators, Stairlifts, Wheelchair Lifts The electrical system designer calculates the maximum available fault current at the elevator controller. 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. 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. The panel further clarified that the marked SCCR value must be adequate for the available fault current to ensure a safe installation. 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. Reinforcing NEC 110.3(B) and NEC 110.10 to require the elevator controller marked SCCR to be equal to or greater than the calculated and As an installer and an inspector, one common issue I've seeen is incompatible connections associated with raceways connections and fittings. NEC Article 620 contains numerous other disconnect provisions, which must be carefully scrutinized prior to design work so the installation is compliant. It is of great importance that power to the various elevator functions can be quickly and reliably removed from the loads in case of emergency or for maintenance and troubleshooting. Auxilliary gutters are permitted in machine and control rooms between controllers, starters and similar apparatuses. 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. Below is a summary of these new 2017 NEC sections: In order to comply with these requirements a chain of events must occur. Elevators with driving machines located on the car or counterweight, or in the hoistway are permitted outside the specified spaces. Freight Elevator Door Control: An Opportunity for Wireless Technology. It states an elevator is permitted to be run by an emergency or standby power system. Electricity is often one of the initial services to fail during a storm. The condition is that all conductors must be insulated for the maximum voltage applied to any conductor within the cables or raceway system, and all live parts of the equipment must be insulated from ground for this maximum voltage. 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. While machine room-less designs have been commercially available for many years, their use may still be unknown to some AHJs. A second door is required if the equipment is rated over 1200 amps and over 6 ft. wide. In driving through commercialized suburban areas, you frequently see paralleled conductors for large retail grocers (where there is a heavy refrigeration load). +;-mka|7! Part X, Emergency and Standby Power Systems, is simple and straightforward. Elevator Pit FC Requirements CE017 - 1 - AppendicesABC - Code 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. Please check your entries and try again. The cover shall be secured and level with the pit floor. 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). With heavy use on a hot day, the oil can overheat, causing elevator shutdown. The architect has a choice of either traction or hydraulic elevators. Shi Liguang, Yao Lianghong, Luo Zhiqun and Wan Jianru, Constructional Stretch and Hoist-Rope Tension . 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. Hoistway pit lighting and receptacles 5. For instance, one method to reduce the available fault current is to add an isolation transformer ahead of the elevator controller. Mohawk Lift Systems Inc, 836 Troy Schenectady Rd, Latham, NY, Elevators 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. 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. 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. 6 feet, and shall meet the requirements of NEC 70 620.21(A)(1)(d). Such vehicles include, but are not . Three wiring categories within hoistways are allowed in addition, each with exceptions. First, you'll need to install lighting in the elevator equipment room (Photo 1) and shaft pit (Photo 2). 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. +90 (216) 348 4876, India Office Corporate Office With the new elevator controller requirements, more attention will be focused on the elevator system. (C) Duplex Receptacle. 68 | WWW.ELEVATORWORLD.COM | June 2012 Continuing Education . ,l7CLHmcX9*F -{Q|^"XL`b1y]$,y *R/2Rn{\xG L*vMP.uKW,)68]Y}+ FYS1B=Q0S>Hc The AHJ is saying that this is a violation of 620.23. wide or the width of the equipment, whichever is greater. NEC 2011 also addresses branch circuits for machine room or control room/machinery space or control-space lighting and receptacles. 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. Elevator cab lights require emergency back-up power. For elevators that regenerate power back into a power source unable to absorb the regenerative power under overhauling elevator load conditions, a means to absorb this power is to be provided. A traditional elevator installation (which includes a machine room) requires access inside the elevator shaft. Cross-sectional areas of conduits are given in Chapter 9, Table 4. Though I understand how someone might argue two. Moreover, because motors have a higher starting current than other loads, the overcurrent protection protocol is unique to them and somewhat counterintuitive. 2023 Endeavor Business Media, LLC. Generally, it is decreed that the supply voltage is not to exceed 300 V between conductors (allowing for the familiar 240-V concept), although there are exceptions. 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. Metal grating shall be installed over the hole that sits flush with the pit floor. z, /|f\Z?6!Y_o]A PK ! 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. 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. +1-251-479-4514 | [emailprotected], Trkiye Office Home Articles Elevator World June 2012 Issue NEC Article 620: Elevators, Part 2. 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 specifies Hoistway wiring, and doesn't seem to distinguish between hoistway and pit. The lighting is not to be connected to a GFCI, because the elevator car is not a place that should experience nuisance tripping. Elevator Pit Drain or Sump Pump | UpCodes Inspecting Elevator Power Wiring - IAEI Magazine NEC Article 620 Part VI, Disconnecting Means and Control, is rather exacting. If you can illuminate the pit using lights that are "above the top of the pit" (whatever that . 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. PDF Elevator Acceptance Inspections - Tennessee Please include what you were doing when this page came up and the Cloudflare Ray ID found at the bottom of this page. !>x=yy Bvv8?~e PK ! In addition, requirements for selective coordination and shunt tripping should be complied with as needed for the installation. This accomplishes two functions. Depending on your local codes, you can do this by installing heat or smoke detectors within 24 in. 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. Hydraulic elevator pit | Electrician Talk Utility-owned electrical structures not directly concerned with electrical generation, transmission and distribution are NEC regulated. Additionally, duty on elevator and dumbwaiter motors is rated as intermittent, whereas duty on escalator and moving-walk motors is considered continuous. A different occurrence involves exposure to the explosive blast when there is a line-to-line or line-to-ground arc blast. 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. Such cable groups are to be supported at intervals not over 3 ft. and located so as to be protected from physical damage. 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. The floor specified as the designated landing, which must be approved by the Fire Marshal, is usually the floor on grade level so passengers can quickly exit to the outside. 3. The light switch shall be located so to be accessible from pit access door. 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). As always, the best advice in all instancesdo your homework, communicate often, and document decisions made. 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 Marking the elevator controller short-circuit current rating (SCCR) by the elevator controller manufacturer. 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. A section on branch circuits for car lighting, receptacles, ventilation, heating and air-conditioning contains a number of important provisions. ) > 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 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. Power for the elevator controller must first enter a lockable safety disconnect device, located adjacent to the door of the equipment room. 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. 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. Additional branch circuits are to supply other utilization equipment not covered above. . Fuses: Verify that the correct size, type and capacity are installed. These are covered for generic, non-elevator specific use in earlier articles, 376 and 378, in Chapter 3, Wiring Methods and Materials. Fluid pressure in the cylinder raises and lowers the elevator cab. Frequently Encountered Items That Delay Accep Tance of New Elevators 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. The disconnecting means is to be in the machine room or similar location, with provision for being locked in the open position. Feeders may be installed within the hoistway where the elevator has a driving-machine motor in the hoistway or on the car or counterweight. Your IP: Because they need to move and flex, traveling cables are not required to be in a raceway. Elevator PITS | Mike Holt's Forum 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) 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. 2m9 `K]f*F gaR The fan should be on a dedicated circuit. (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. 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. We shall now take a look at the principle requirements of Article 620, with particular emphasis on wiring requirements for elevator shafts, machine rooms and cars. There are options available to achieve this depending upon the customers needs. Each of these performs a different function, and the wiring mandates vary accordingly. 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. The idea is quite simple. The light switch for the equipment room must be adjacent to the entrance door on the latch side. The electrical conductors and equipment for non-mine elevators that extend below grade are under NEC jurisdiction. Indeed, most elevator accidents involve maintenance workers, yet even theirs is not an excessively dangerous profession. 953 0 obj <> endobj You may go up to 600 V for power circuits supplying door-operator controllers and door motors, branch circuits and feeders to motor controllers, driving-machine motors, machine brakes and motor-generator sets.