Overcurrent devices protecting these branch circuits are to be located in the machine room or similar location. ) > 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 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. 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. NFPA 72 requires the control circuit between the Fire Alarm System and the shunt trip be monitored for integrity. Dont troubleshoot unless you can keep your shoe/boot soles dry. Indeed, most elevator accidents involve maintenance workers, yet even theirs is not an excessively dangerous profession. hb``` ea``j~p2nfH 'xXg00,/(_ Iq8PDdg-~ s$!XI;Fn0vu `h`R 1y 0B.":9.@, e`xI;=7O3fvbb8:SC;%O*20] The traveling cable, moreover, may be run without raceway from inside the hoistway to elevator-controller enclosures and to the elevator car and machine room and similar locations outside the hoistway for a distance not exceeding 6 ft. The traveling cable, of necessity, is exempted. For example, it is stated that the cross-sectional area of the individual conductors in a wireway are not to exceed 50% of the interior cross-sectional area of the wireway. 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. In these installations, it is best to design the elevator controller so the elevator controller SCCR is adequate for the available fault current. Doors must open in the direction of travel and be equipped with panic bars, pressure plates or other devices that are normally latched but open under simple pressure. Cross-sectional areas of conduits are given in Chapter 9, Table 4. 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). Please check your entries and try again. And so the needs can be very different. The two documents are in harmony and should be used in conjunction. This will normally require you to vent the room with a fire/smoke damper and include smoke detector signals in the control logic. Hydraulic reservoir characteristic of a hydraulic-piston-operated elevator. The circuit(s) for the lighting and receptacles must be dedicated to the elevator area only. Section 620.62, Selective Coordination, is central to multi-elevator installations and must be closely observed. IAEI News Magazine. 988 0 obj <>stream 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.. 974 0 obj <>/Filter/FlateDecode/ID[<64E135C225F1064D91BC8119D14516A9>]/Index[953 36]/Info 952 0 R/Length 105/Prev 204101/Root 954 0 R/Size 989/Type/XRef/W[1 3 1]>>stream 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. Finally, typical installations and compliance with all these requirements will be discussed. 23.254.250.15 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. 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. Have wiring identified for use in wet locations in accordance with the requirements in NFPA 70. [emailprotected] 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. The drain or sump pump discharge shall be into the sanitary or storm drainage system through an indirect waste connection. Elevator power disconnect (with utility feed marking) located in the machine room or other permitted location. 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. -inch conduit is needed to the sump pump. ), advise the building owner to correct the condition. 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. 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. As stated in Section 7 of the Elevator Industry Field Employees Safety Handbook: Unless it is not feasible, (i.e. However, this can vary depending on building conditions and exterior grade. This is especially true in an elevator shaft where measures have to be taken to ensure that a hazardous situation is not created. 2023 Endeavor Business Media, LLC. Since 1953, Elevator World, Inc. has been the premier publisher for the global vertical transportation industry. It is further specified the machine-room lighting switch be located at the point of entry. Hydraulic elevators are typically more cost effective and used for buildings up to 5-6 stories. 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. Therefore, elevator equipment rooms must maintain a temperature between 50F and 90F. If power is not being supplied to the elevator controller (e.g., open mainline fuses, etc. Auxilliary gutters are permitted in machine and control rooms between controllers, starters and similar apparatuses. Even though Edison grasped the basic ideas of fusing and overcurrent protection, many hazards remained. 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. Dan Neeser is a Senior Field Application Engineer with Eatons Bussmann Division. The traveling cable or raceway is also permitted to include shielded conductors and/or one or more coaxial cables. 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. For instance, one method to reduce the available fault current is to add an isolation transformer ahead of the elevator controller. If the equipment must remain energized to perform work, effective insulation and safe electrical working practices should be observed. First, you'll need to install lighting in the elevator equipment room (Photo 1) and shaft pit (Photo 2). If we fast forward more than 36 centuries, we see some important new developments in elevator technology. Here are 23 ways that both chapters and the national office can meet todays major challenge of making members feel valued, IAEIs Online Training allows you to learn at your own pace or live with an expert instructor, from the comfort of your laptop or PC. Notice the definition mentions the full range of operating times. 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. 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. 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. Where voltages exceed 600, a sign reading DANGER HIGH VOLTAGE is required. Elevator cab lights require emergency back-up power. NEC Article 0: Elevator art by David Herres Continued. f?3-]T2j),l0/%b 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. For platform lifts and stairway chairlifts, the duty is intermittent. Flexible metal, liquid-tight flexible metal or liquid-tight flexible nonmetallic conduit 3/8 in. This is typically accomplished via a shunt trip device. These 29 CFR 1910.146 (c) (8) requirements are: 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. All Rights Reserved | Contact Us | Privacy Policy. from the exposed components, and the incident energy calculated at 18 in. Feeders may be installed within the hoistway where the elevator has a driving-machine motor in the hoistway or on the car or counterweight. A further requirement concerns elevator-car air-conditioning and heating. (g) Stop Switch in Pits. 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. [emailprotected] Such design innovations require sophisticated wiring strategies. 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. +91 8025357028, 2022 Elevator World, LLC. Since 1953, Elevator World, Inc. has been the premier publisher for the global vertical transportation industry. Hint: Duct Tape to the Rescue, NEC: Air Conditioning and Refrigerating Equipment Part 5. Additionally, duty on elevator and dumbwaiter motors is rated as intermittent, whereas duty on escalator and moving-walk motors is considered continuous. A separate branch circuit shall supply the hoistway pit lighting and receptacle (s). You need to Subscribe to continuing reading. 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. High-rise buildings pose additional concerns. 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. Selective coordination is also required for multiple elevators per NEC 620.62. Additional branch circuits are to supply other utilization equipment not covered above. (A) Separate Branch Circuit. The cord is to be a hard-usage, oil-resistant type not over 6 ft. in length. No provision is to be made to automatically restore power. 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. 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. You are seeing this message for one of three reasons: You have reached your limit of free content. Article 511 provides the requirements for commercial garages areas used for the storage or repair of self-propelled vehicles that use combustibles (liquid or gas) for power. or larger, not over 6 ft. in length. In elevators provided with Firefighters' Emergency Operation, a drain or sump pump shall be provided. 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 next section, 620.36, concerns different systems in one raceway or traveling cable. If the building has emergency power available, use it to supply the cab lights. The proposals resulted in adding new requirements in the 2017 NEC for: Marking the elevator controller short-circuit current rating (SCCR) by the elevator control-ler manufacturer. If you can illuminate the pit using lights that are "above the top of the pit" (whatever that . (A) tells us that the lighting and receptacle (s) for the pit must be on separate circuits. Notwithstanding, if sprinklers are installed in hoistways, machine rooms or the like, the disconnecting means is permitted to automatically open the power supply to the affected elevator(s) prior to the application of water. This lighting and receptacle circuit is separate from the circuit serving the motor. 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 feeder OCPD needs to remain closed so the remaining elevators have power and continue to function. For this reason, the NEC provides for adequate working space around electrical equipment that may need to be serviced. Sign up for our free e-newsletter. Elevators with driving machines located on the car or counterweight, or in the hoistway are permitted outside the specified spaces. 3. Every building is different. By subscribing, you agree to our User Agreement and Privacy Policy & Cookie Statement. An example would be the elevator, as well as all wiring in a utility-owned administration building. David Herres Louisiana State Uniform Construction Code Council adopts the 2014 NEC, Basic three-phase power measurements explained, Safety After the Storm Operating Portable Generators. Examples of PPE that may be appropriate are non-conductive eye protection, clean leather or fire-resistant gloves, and natural-fiber or fire-resistant-rated long-sleeved shirts and pants, or fire-resistant-rated long-sleeved coveralls. This room is to be secured against unauthorized access (kept locked). 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. 2. Special conditions: Troubleshooting in wet, hot or cold conditions calls for extra caution. Any other utilization equipment associated with the elevator 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. The fan should be on a dedicated circuit. 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). 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. Required lighting shall not be connected to the load side of a ground-fault circuit interrupter. 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. +90 (216) 348 4876, India Office 6 Stop Switch in Pits There shall be installed in the pit of each elevator an ASME A17.1 CODE enclosed stop switch or switches meeting the requirements The following material is reprinted with permission from the American of 2.26.2.7 and 2.2.6.1 through 2.2.6.3. Installing electrical equipment where its SCCR is less than the available short-circuit current creates serious safety hazards. The action you just performed triggered the security solution. 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. 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. 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. The two main types of elevators are hydraulic and traction. 836 Troy Schenectady Road ; Latham, NY 12110 . 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? It does specify wiring methods allowed, though, in 620. Many people use portable generators until power is restored. Apr 24, 2013. correct me if I'm wrong, but I believe it's damp. (All intentionally grounded elements must be held at equal potential.) 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. In fact, an entire elevator system for a project is most often designed and specified by the architect who has little understanding of the electrical distribution system. Elisha Otis safety elevator, introduced in 1853, prevented the fall of the car if the cable broke. Freight Elevator Door Control: An Opportunity for Wireless Technology. Additionally, ampacities of the individual conductors and flame-retardant properties of the overall cable are important factors. Machine room/control space lighting and receptacles 4. NEC Article 620 Part IV, Installation of Conductors, contains key mandates for elevator wiring. But by understanding how these items fit together and what purpose they serve, you can have a successful project. Additional requirements concern escape routes. Years may lapse between the design and installation stages of a 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. 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. 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 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. Part II of Article 620 concerns conductors used in elevator work, and several important requirements are covered. The conduit alone can't act as the grounding means. The light switch for the equipment room must be adjacent to the entrance door on the latch side. Hoistway pit lighting and receptacles 5. The vast majority of equipment serving the elevator is located within this room (i.e., elevator controller). 354 Morgan Ave. Pit drainage must be designed to eliminate a minimum capacity of 3,000 gallons per hour (or 50 GPM) per elevator car. Otherwise, specify that the elevator supplier provide a battery back-up unit to power the lights in the event of an outage. With heavy use on a hot day, the oil can overheat, causing elevator shutdown. The surest means of avoiding an arc-flash hazard is to lockout and tagout the electrical service to a controller. 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. 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. To address this issue, Code Making Panel (CMP) 12 of the National Electrical Code acted on several proposed changes to Article 620 during the revision cycle for the 2017 NEC that deal with the proper installation of elevator controllers. If a smoke detector goes into alarm, it signals the elevator to go into Fire Recall Function, at which point the controller directs the elevator cab to travel to its pre-programmed designated landing, open its doors, and remain stopped there until the alarm clears. 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. There are options available to achieve this depending upon the customers needs. The code exempts some fairly broad areas where compliance is not expected. 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. It employs specialists in Mobile, Alabama, and has technical and news correspondents around the world. NEC Article 620 Part VI, Disconnecting Means and Control, is rather exacting. If the disconnecting means is an integral part of the motor controller, it is to be operable without requiring opening of the enclosure. 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. NEC has a further note that the term wheelchair lift has been changed to platform lift.. Even non-composite fiber-optic cable, which does not carry electrical energy, is subject to the code. NEC Article 620 Part V, Traveling Cables, is driven by two major issues. 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. However, when I've put in elevators, NEC seems to always take a back seat to ANSI, which seems . For instance, a typical elevator controller may traditionally have SCCR ratings from 5 to 10 kA. endstream endobj 954 0 obj <. As mentioned, traditional installations of a traction or hydraulic elevator include a separate machine room. NEMA 4 : All electrical equipment, located less than 1225 mm (48 in.) Related Code Sections 802.1.8 Indirect/Special Waste, Elevator Pit Drain or Sump Pump 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. (f) Illumination of Pits. 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. Sumps and sump pumps in pits, where provided, shall be covered. Something went wrong. Many NEC articles address voltage limitations, and Article 620 is no exception. Mainline disconnect: DO NOT OPEN THE MAINLINE DISCONNECT SWITCH COVER unless employees are authorized, properly trained and appropriate measures are taken commensurate with the higher risk of arc-flash hazards. The disconnecting means is to be in the machine room or similar location, with provision for being locked in the open position. Utility-owned electrical structures not directly concerned with electrical generation, transmission and distribution are NEC regulated. Home Articles Elevator World June 2012 Issue NEC Article 620: Elevators, Part 2. The panel further clarified that the marked SCCR value must be adequate for the available fault current to ensure a safe installation. Cloudflare Ray ID: 7a2fbe9ebd7e2fe8 Performance & security by Cloudflare. 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. The code notes that elevator rails or other hoistway equipment are not to be used as the grounding conductor for lightning-protection systems. By subscribing, you agree to our User Agreement and Privacy Policy & Cookie Statement. The electrical system designer calculates the maximum available fault current at the elevator controller. All Rights Reserved | Contact Us | Privacy Policy. First, it is now clear that elevator controllers must be marked by the manufacturer with their SCCR. The disconnecting means must disconnect the elevator from the emergency, standby and normal power systems. Fluid pressure in the cylinder raises and lowers the elevator cab. Another important electrical system design consideration for supplying power to multiple elevators is NEC 620.62. 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. Fireman telephone jacks and telephone cabling are typically sufficient for each of these locations. Society of Mechanical Engineers. +1-251-479-4514 | [emailprotected], Trkiye Office Thus, the traveling cable must be supported by a steel supporting member. Specifically, Section 725.43 provides that overcurrent protection for conductors 14 AWG and larger is to be provided in accordance with the conductor ampacity without applying ampacity adjustment and correction factors. . GFI Receptacles: GFI receptacles shall be required in all elevator machine rooms, machinery spaces and elevator pit areas. 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. 0 endstream endobj startxref +1-251-479-4514 | [emailprotected], Trkiye Office In case of emergency, electricians, maintenance personnel and any elevator technicians called in to the premises should have ready access to the key. 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. Your elevator supplier will take care of all the wiring and related code requirements for the elevator cab and the various controls. Motors for traction elevators were traditionally DC or synchronous, but new installations use AC motors and VFDs for speed control.
