Personal protective equipment (PPE): Use appropriate PPE to protect body parts within the range of 3-16 in. They must be in enclosures with doors or removable panels that can be locked in the closed position. 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. Please check your entries and try again. It employs specialists in Mobile, Alabama, and has technical and news correspondents around the world. Other codes and standards interact with the NEC, and it is necessary to see how they all work together in order to create safe and compliant elevator designs/installations. An example would be the elevator, as well as all wiring in a utility-owned administration building. 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. This is not the elevator companys responsibility. ) > 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 After reading this article, you should have learned about: The meanings of definitions for control room and control space versus machine room The purpose and specifications for working spaces Insulation types and minimum sizes of conductors Requirements for feeder and branch-circuit conductors Feeder demand factors for ele-vators. It is important for design engineers to communicate this with the architect and owner during the design phase, as it will impact space needs elsewhere in the facility to accommodate electrical equipment. , !! 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. 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. Three wiring categories within hoistways are allowed in addition, each with exceptions. NEC Article 620 contains numerous other disconnect provisions, which must be carefully scrutinized prior to design work so the installation is compliant. This is something that can be easily accomplished if the elevator controller manufacturer uses components in combination with overcurrent protective devices that are tested and listed with high combination SCCRs. It begins by considering metal and nonmetallic wireways. 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. It is of great importance for the design engineer to communicate with their local authority having jurisdiction (AHJ) to determine fire alarm requirements for the respective elevator installation. The conduit alone can't act as the grounding means. In case of emergency, electricians, maintenance personnel and any elevator technicians called in to the premises should have ready access to the key. This will normally require you to vent the room with a fire/smoke damper and include smoke detector signals in the control logic. 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. Accordingly, the supply wires are protected only for short circuit, and the overload protection is provided closer to the motor. These are part of Article 725, Class 1, Class 2 and Class 3 Remote-Control, Signaling, and Power-Limited Circuits. This may be countered by providing good machine-room ventilation. N _rels/.rels ( j0@QN/c[ILj]aGzsFu]U ^[x 1xpf#I)Y*Di")c$qU~31jH[{=E~ Limit switches placed throughout the height of the shaft communicate with the controller and stop the cab at each landing. h-`7 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. 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. Shi Liguang, Yao Lianghong, Luo Zhiqun and Wan Jianru, Constructional Stretch and Hoist-Rope Tension . Corporate Office The most complex of these is the elevator. Follow the manufacturers instructions and precautions. 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. NEC 2011 also addresses branch circuits for machine room or control room/machinery space or control-space lighting and receptacles. 23.254.250.15 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. Moreover, it is necessary to consider future worker safety for an indefinite period. above the pit floor, shall: Be weatherproof (NEMA 4). As stated in Section 7 of the Elevator Industry Field Employees Safety Handbook: Unless it is not feasible, (i.e. (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. The NEC rule specifies that the minimum size for paralleled conductors is 1/0 AWG, which is much too big for an elevator traveling cable. 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). 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. First, you'll need to install lighting in the elevator equipment room (Photo 1) and shaft pit (Photo 2). 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? Installing electrical equipment where its SCCR is less than the available short-circuit current creates serious safety hazards. NFPA 72 requires the control circuit between the Fire Alarm System and the shunt trip be monitored for integrity. But the lights don't have to be in the pit itself. NEC Article 620 Part V, Traveling Cables, is driven by two major issues. 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. You can email the site owner to let them know you were blocked. 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. 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. Instruments: Use category III multimeters and be familiar with their use and limitations. The branch circuit supplying these units is to be similarly dedicated, with the associated overcurrent device located in the machine room or similar location. The code exempts some fairly broad areas where compliance is not expected. 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. Have wiring identified for use in wet locations in accordance with the requirements in NFPA 70. 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. Car lighting, receptacles and ventilation 2. 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. 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. The surest means of avoiding an arc-flash hazard is to lockout and tagout the electrical service to a controller. Elevators with driving machines located on the car or counterweight, or in the hoistway are permitted outside the specified spaces. Machine room/control space lighting and receptacles 4. (ASME has a separate document, A18.1-2008 Safety Standard for Platform Lifts and Stairway Lifts). Thus, the need for door interlock functionality is recognized. Modern electronic elevator controls can be sensitive to temperature shifts. The two documents are in harmony and should be used in conjunction. He is saying that each pit requires a separate circuit, in other words "dedicated". 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. This accomplishes two functions. These must also be insulated for the maximum voltage applied to any conductor within the cable or raceway system. 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. Additionally, duty on elevator and dumbwaiter motors is rated as intermittent, whereas duty on escalator and moving-walk motors is considered continuous. You are a subscriber that needs to Sign In. [emailprotected] The lighting is not to be connected to a GFCI, because the elevator car is not a place that should experience nuisance tripping. 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. The fan should be on a dedicated circuit. 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. Click to reveal +91 8025357028, 2022 Elevator World, LLC. 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. The feeder OCPD needs to remain closed so the remaining elevators have power and continue to function. All rights reserved. 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.. Hard-service cords are permitted only as flexible connections for the top-of-car operating device or the car-top work light. These 29 CFR 1910.146 (c) (8) requirements are: 2.2.2.6 . The cover shall be secured and level with the pit floor. 4.0 (2 Reviews) (2) CLAIMED . There are options available to achieve this depending upon the customers needs. 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. We generally think of the 19th century as the great age of building codes. The Code provides guidance through regulations to establish requirements. or larger, not over 6 ft. in length. 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. Each fused switch or circuit breaker in the panelboard is used as an elevator disconnect. NEC Guidelines on Commercial Garages. Home Articles Elevator World April 2012 Issue NEC Article 620: Elevators, Part I. As an installer and an inspector, one common issue I've seeen is incompatible connections associated with raceways connections and fittings. For current-limiting fuses, the information to achieve selective coordination has been available for many years in fuse amp ratio tabular form. 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. Pit drainage must be designed to eliminate a minimum capacity of 3,000 gallons per hour (or 50 GPM) per elevator car. Additional requirements concern escape routes. Mike Holt. 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). [emailprotected] You are a subscriber that needs to Sign In. These are covered for generic, non-elevator specific use in earlier articles, 376 and 378, in Chapter 3, Wiring Methods and Materials. 836 Troy Schenectady Road Latham, NY 12110 . 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. : inspecting; troubleshooting; observing; etc.) Nevertheless, the primary NEC focus is on elevators, and the intention is to mitigate the hazards associated with the use of electricity. Society of Mechanical Engineers. 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. 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. 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. . Here, the National Electrical Safety Code has jurisdiction. In all cases, the working space must permit at least a 90 opening of equipment doors or hinged panels. If it kills the son of the owner, the son of that builder shall be put to death.. PK ! Use the below learning-reinforcement questions to study for the Continuing Education Assessment Exam available online at www.elevatorbooks.com or on page 111 of this issue. Name the principal code other than NEC that pertains to elevator design/installation. What is the definition of the machine room? Why are voltage limitations important? In which areas must live parts be enclosed? Why are feeder demand factors permitted for multiple elevators? Marking the available short-circuit (fault) current on the controller by the equipment installer. Feeders may be installed within the hoistway where the elevator has a driving-machine motor in the hoistway or on the car or counterweight. However, when I've put in elevators, NEC seems to always take a back seat to ANSI, which seems . Such cable groups are to be supported at intervals not over 3 ft. and located so as to be protected from physical damage.
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