The design engineer must identify the available fault current at the elevator controller to the installer so an elevator controller with adequate SCCR can be provided. Though I understand how someone might argue two. 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). Section 620.62, Selective Coordination, is central to multi-elevator installations and must be closely observed. Hoistway pit lighting and receptacles 5. 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. 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) A different occurrence involves exposure to the explosive blast when there is a line-to-line or line-to-ground arc blast. A section on branch circuits for car lighting, receptacles, ventilation, heating and air-conditioning contains a number of important provisions. 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. IAEI News Magazine. As stated in Section 7 of the Elevator Industry Field Employees Safety Handbook: Unless it is not feasible, (i.e. It is further specified the machine-room lighting switch be located at the point of entry. ^W i word/document.xml=nr]6Id=,_$j9-"Y.iGU\h_}. 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). 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. 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. 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? 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. He had been with Eaton (Cutler-Hammer and Bussmann) since 1993 and specializes in training on the design and application of overcurrent protective devices and equipment in electrical distribution systems in accordance with the National Electrical Code and equipment in accordance with the various product standards. The most complex of these is the elevator. For example, wiring that is under exclusive utility control and has to do with the generation and distribution of electrical power is not NEC regulated. Conductors supplying a single motor are to have an ampacity not less than the percentage of motor nameplate current determined from Section 430.22(A) and (E). The locking capability is important so during maintenance, the equipment will not be inadvertently energized. The cord is to be a hard-usage, oil-resistant type not over 6 ft. in length. Working spaces for electrical equipment that may have to be examined, adjusted, serviced or maintained is required in all occupancies in an earlier NEC section, 110.26(A). Metallic articles: Remove metallic articles such as watches, chains, bracelets, earrings, belt buckles and keychains before troubleshooting. Because they need to move and flex, traveling cables are not required to be in a raceway. 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. If the disconnecting means is an integral part of the motor controller, it is to be operable without requiring opening of the enclosure. However, space is frequently limited within the shaft and as such many ancillary components (shunt trip circuit breakers, fused disconnects) may need to be located outside of the elevator shaft. 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). The drain or sump pump discharge shall be into the sanitary or storm drainage system through an indirect waste connection. Other terms defined in NEC Article 620 are Control System, Motion Controller, Motor Controller, Operation Controller, Operating Device and Signal Device. You are seeing this message for one of three reasons: You have reached your limit of free content. 2. or larger, not exceeding 6 ft. in length, are permitted between control panels and machine motors, machine brakes, motor-generator sets, disconnecting means and pumping motors and valves. 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. h-`7 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. 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. The feeder OCPD needs to remain closed so the remaining elevators have power and continue to function. Modern electronic elevator controls can be sensitive to temperature shifts. 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. of the sprinkler heads. 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. 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. The next section, 620.36, concerns different systems in one raceway or traveling cable. If we fast forward more than 36 centuries, we see some important new developments in elevator technology. Use Underwriters Laboratories or Canadian Standards Association-labeled scopes tested for 1,000 V. Lockout/tagout: When troubleshooting is complete and further work can be accomplished without the equipment being energized, follow the lockout/tagout procedures in Section 7 of the. Moreover, it is necessary to consider future worker safety for an indefinite period. Cloudflare Ray ID: 7a2fbe9ebd7e2fe8 Here, the National Electrical Safety Code has jurisdiction. Requirements in Article 620 modify the articles in Chapter 3. 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. If the entire feeder/branch circuit assembly were to be protected in the conventional manner, the motor would cut out long before reaching operating speed. The Code provides guidance through regulations to establish requirements. . (C) Duplex Receptacle. +1-251-479-4514 | [emailprotected], Trkiye Office 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. NEC 2011 Article 620.21(2)(b) states that hard-service cords and junior hard-service cords that conform to the requirements of Article 400 (Table 400.4) are permitted as flexible connections between the fixed wiring on the car and devices on the car doors or gates. 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. 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. +;-mka|7! Nevertheless, the primary NEC focus is on elevators, and the intention is to mitigate the hazards associated with the use of electricity. Home Articles Elevator World June 2012 Issue NEC Article 620: Elevators, Part 2. , !! The sump pump/drain shall have the capacity to remove a minimum of 11.4 m. 3 /h (3,000 gal/h) per elevator. The light switch for the equipment room must be adjacent to the entrance door on the latch side. 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. This requirement applies to all controllers, disconnecting means and other electrical equipment that may need servicing, inspection or maintenance. The disconnecting means must disconnect the elevator from the emergency, standby and normal power systems. 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. Finally, in 1897, the first National Electrical Code (NEC) appeared. Elevators with driving machines located on the car or counterweight, or in the hoistway are permitted outside the specified spaces.
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