As we have seen, a limited number of these are approved for elevator locations car, hoistway, pit and machine room. If the disconnecting means is an integral part of the motor controller, it is to be operable without requiring opening of the enclosure. All elevator hoistways must be equipped with a sump pit located at the rear of the elevator pit. 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. 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. 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. Many people use portable generators until power is restored. All Rights Reserved | Contact Us | Privacy Policy. Elevator PITS | Mike Holt's Forum The demand factors are given in Table 620.14, which allows significant reductions as the number of motors is increased. You can email the site owner to let them know you were blocked. N _rels/.rels ( j0@QN/c[ILj]aGzsFu]U ^[x 1xpf#I)Y*Di")c$qU~31jH[{=E~ Conductors supplying a single power transformer are to have an ampacity not less than the nameplate current rating of the power transformer plus all other connected loads. ) > word/_rels/document.xml.rels ( N0HC;qRN/W$#{1EM]ZY|vj5h),-g!`./V/KKFY4D#la&V#=$Q7|l/d#hS 7+IDZ!J 6KucD^s`+>=(3E !>x=yy Bvv8?~e PK ! Home Articles Elevator World June 2012 Issue NEC Article 620: Elevators, Part 2. NEC Article 620 Part V, Traveling Cables, is driven by two major issues. Traditional wiring methods and materials come into play, as always, but it is necessary to rethink their deployment. Jul 15, 2021. Every building is different. Traction elevators raise and lower the elevator cab with cables, a pulley system, and counter weights powered by a motor at the main drive wheel. (To design and install an elevator for a Class I, Division 1 location would be quite an undertaking.). 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). Here, the National Electrical Safety Code has jurisdiction. Performance & security by Cloudflare. 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. The fan should be on a dedicated circuit. These must also be insulated for the maximum voltage applied to any conductor within the cable or raceway system. 2m9 `K]f*F gaR This room is to be secured against unauthorized access (kept locked). And so the needs can be very different. The electrical system designer calculates the maximum available fault current at the elevator controller. In such cases, it's economically justifiable to specify a traction type elevator. The elevator controller manufacturer must determine the required elevator controller SCCR as stated in the elevator controller specification and provide an elevator controller SCCR that is equal to or greater than the available fault current thats indicated in the design documents where there are multiple elevator controllers at different locations. Part II of Article 620 concerns conductors used in elevator work, and several important requirements are covered. All rights reserved. If we fast forward more than 36 centuries, we see some important new developments in elevator technology. An example would be the elevator, as well as all wiring in a utility-owned administration building. If you can illuminate the pit using lights that are "above the top of the pit" (whatever that . 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. 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. The usual scenario for electrical injury is shock when electrical current passes through the human body. These are the principle NEC 2011 Article 620 mandates. 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.. 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. 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. Cables used in Class 2 power-limited circuits are permitted between risers and signal equipment and operating devices, provided they are supported and protected from physical damage and are of the jacketed and flame-retardant type. (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. 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. endstream endobj startxref A different occurrence involves exposure to the explosive blast when there is a line-to-line or line-to-ground arc blast. The lighting is not to be connected to a GFCI, because the elevator car is not a place that should experience nuisance tripping. This accomplishes two functions. 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). Years may lapse between the design and installation stages of a project. It employs specialists in Mobile, Alabama, and has technical and news correspondents around the world. Such vehicles include, but are not . In elevators provided with Firefighters' Emergency Operation, a drain or sump pump shall be provided. NEC Article 620 Part VI, Disconnecting Means and Control, is rather exacting. The two documents are in harmony and should be used in conjunction. 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. You must locate this key switch at the main lobby or at the building fire command center. You'll be responsible for specifying the items related to the fire alarm and some controls, as well as supplying lighting and power to the equipment room and elevator pit. Because of this, there is often a communications gap between the electrical system designer, whose design typically stops at the required elevator disconnecting means, and the architect who designs the elevator system. Marking the elevator controller short-circuit current rating (SCCR) by the elevator controller manufacturer. We have circuited the receptacles and lights in the pits to the same circuit. This is especially true in an elevator shaft where measures have to be taken to ensure that a hazardous situation is not created. 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. Both electric and nonelectric elevators are to comply with Article 250, the code article that covers grounding and bonding in general. 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. Provide continuous, non -slip, horizontal rungs every 12" for the full height of the pit ladder. 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. 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. While machine room-less designs have been commercially available for many years, their use may still be unknown to some AHJs. PDF Elevator Acceptance Inspections - Tennessee 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? 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. Dont troubleshoot unless you can keep your shoe/boot soles dry. Required lighting shall not be connected to the load side of a ground-fault circuit interrupter. This position paper is written to provide guidance to members whose employees are engaged in elevator-industry work that might expose them to arc-flash hazards, and to assist members in complying with applicable OSHA and National Fire Protection Association (NFPA) standards. from the exposed components, and the incident energy calculated at 18 in. You need to Subscribe to continuing reading. 4.0 (2 Reviews) (2) CLAIMED . The two primary hazards are fire and electric shock or arc flash, although there are others. 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. 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. 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 specifies Hoistway wiring, and doesn't seem to distinguish between hoistway and pit. 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. Always verify all conditions and requirements with the state and the AHJ where the installation is taking place. 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. The panel further clarified that the marked SCCR value must be adequate for the available fault current to ensure a safe installation. First, the ATS signals the elevators that it's about to switch over to emergency power preferably 30 sec or more prior to switching, which allows the elevator controller to bring each elevator cab to the nearest landing and stop, thus protecting the motors and electrical system. Finally, typical installations and compliance with all these requirements will be discussed. . If this is not done and the available fault current exceeds the elevator controller SCCR, other solutions to reduce fault current must be reviewed or equipment changes and field evaluations may be needed. The fire loading resulting from an accumulation of abandoned low-voltage cabling may be considerable, and has to be understood and dealt with. The drain or sump pump discharge shall be into the sanitary or storm drainage system through an indirect waste connection. 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. No provision is to be made to automatically restore power. z!0: - [Content_Types].xml ( n0EUb*>-RxV=QUAl"93dFk%Y?l}MGDV To avoid this situation, designers can specify elevator controls with a safety feature commonly called a rescuvator. If power is not being supplied to the elevator controller (e.g., open mainline fuses, etc. PDF Elevator Safety Program - Technical Clarification Such cable groups are to be supported at intervals not over 3 ft. and located so as to be protected from physical damage. 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) ^W i word/document.xml=nr]6Id=,_$j9-"Y.iGU\h_}. A section on branch circuits for car lighting, receptacles, ventilation, heating and air-conditioning contains a number of important provisions. 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. Hazards created by water, snow or condensation in the work area can cause slips, falls and accidental contact. 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. Similar provisions are attached to elevator-car heating and air-conditioning disconnecting means, and to other utilization equipment. Dec. 21, 2010. Inspecting Elevator Power Wiring - IAEI Magazine hb``` ea``j~p2nfH 'xXg00,/(_ Iq8PDdg-~ s$!XI;Fn0vu `h`R 1y 0B.":9.@, e`xI;=7O3fvbb8:SC;%O*20] NEC Article 620 Part IV, Installation of Conductors, contains key mandates for elevator wiring. wide or the width of the equipment, whichever is greater. 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. Have wiring identified for use in wet locations in accordance with the requirements in NFPA 70. 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. (Cross-sectional areas of conductors are given in Chapter 9, Tables 5 through 8. NEC has a further note that the term wheelchair lift has been changed to platform lift.. 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. 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. Feeders may be installed within the hoistway where the elevator has a driving-machine motor in the hoistway or on the car or counterweight. : inspecting; troubleshooting; observing; etc.) 6 feet, and shall meet the requirements of NEC 70 620.21(A)(1)(d). ranged from 0.06 cal/cm2 to 0.95 cal/cm2, which indicates that the arc-flash hazard to employees is primarily to the hands and arms. It is worth noting that these NEC terms, used throughout Article 620, have been chosen to correlate with A17.1-2007 usage. In contrast to the lighting, these receptacles must be connected to GFCI devices. It does specify wiring methods allowed, though, in 620. Because they need to move and flex, traveling cables are not required to be in a raceway. Section 620.62, Selective Coordination, is central to multi-elevator installations and must be closely observed. ASME A17.1, Section 2.2.5, National Electrical Code, Rule 620-85 4. Elisha Otis safety elevator, introduced in 1853, prevented the fall of the car if the cable broke. The two main types of elevators are hydraulic and traction. A traction elevator's equipment room is typically located at the top of the building, directly over or adjacent to the shaft. But by understanding how these items fit together and what purpose they serve, you can have a successful project. 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. Your elevator supplier will take care of all the wiring and related code requirements for the elevator cab and the various controls. +1-251-479-4514 | [emailprotected], Trkiye Office (ASME has a separate document, A18.1-2008 Safety Standard for Platform Lifts and Stairway Lifts). 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 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. If it kills the son of the owner, the son of that builder shall be put to death.. A traditional elevator installation (which includes a machine room) requires access inside the elevator shaft. 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. The same figure applies to nonmetallic wireways. David Herres [emailprotected] Get more of Elevator World. However, this can vary depending on building conditions and exterior grade. Guidance in determining whether elevator pits meet the definition of 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. This lighting and receptacle circuit is separate from the circuit serving the motor. 354 Morgan Ave. The fan should be on a dedicated circuit. 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 need not be exactly centered on the equipment, and working spaces of adjacent pieces of equipment may overlap. Other terms defined in NEC Article 620 are Control System, Motion Controller, Motor Controller, Operation Controller, Operating Device and Signal Device. 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. Please check your entries and try again. 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. With heavy use on a hot day, the oil can overheat, causing elevator shutdown. 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. Cloudflare Ray ID: 7a2fbe9ebd7e2fe8 1993 NEC 15-20 Amp 120 volt Receptacle Requirements: Wet bar sinks, all bathrooms, roof tops, elevator machines rooms, elevator car tops, elevator pits. 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. (g) Stop Switch in Pits. Hydraulic elevator pit | Electrician Talk 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. Cross-sectional areas of conduits are given in Chapter 9, Table 4. Hydraulic elevators comprise a hydraulic reservoir, pump, cylinder, and controller. This may be countered by providing good machine-room ventilation. Part VIII, Machine Rooms, Control Rooms, Machinery Spaces, and Control Spaces, states elevator and similar-installation driving machines, motor-generator sets, motor controllers and disconnecting means are to be installed in a room or space set aside for that purpose.