Article 90 explains that the NEC is not a design manual, and it assumes that anyone using the Code has a certain level of expertise. B. overcurrent devices do not have to be readily accessible if The grounded circuit (system) conductor is generally not permitted to be used to ground, A: Amotorcontrollerisadeviceorcombinationofdevices,thatcancontrolhowanelectricmotor, A: According to question we have to discuss about A service disconnection means must be installed, A: two types of signaling mode with a neat diagram, A: With industry input, the TIA/EIA cable standards have been developed by the Telecommunications, A: According to article 702 - Optional Standby System Exterior protected locations under canopies, roofs, porches, and similar sites are considered damp locations. C. A single conduit is not permitted as sole support for an FS-type or weatherproof junction box. A nongrounding-type receptacle may be replaced with a grounding-type receptacle where supplied through a ground-fault circuit-interrupter; the replacement receptacle shall be marked "GFCI Protected" and "No Equipment Ground;" an equipment grounding conductor may not be connected to such grounding-type receptacles. An AFCI is basically like a GFCI but it will protect the entire circuit from the breaker and back. Where the ampacity of the ungrounded conductors doesn't correspond with the standard rating of overcurrent protection devices as listed in 240.6(A), you can use the next higher protection device if it doesn't exceed 800A [240.4(B)]. Next we will jump to 240.24 Location in or on Premises. 2). For fire pumps, conductors may be protected for short circuit only; and. fire protection system.D. communications system installation.C. Location Dry A. Overcurrent devices shall be readily accessible and shall be installed so that the center of the grip of the operating handle of the switch or circuit breaker, when in its highest position, is not more than 2.0 m (6 ft 7 in.) 1. contiguous. A system conductor that is required to be grounded by the provisions of paragraph (g)(2) of this section shall be bonded to the generator frame where the generator is a component of a separately derived system. Not be located where they will be in the . If the door is an inswing type, ensure the opened door will not block the transformer vent. 240.6(A). 450.9 provides ventilation requirements, and Sec. Overcurrent devices do not have to be readily accessible if ____. Branch Circuit Multi-wire Multi-wire circuit consists of one (or more) duplex receptacles, one or more multiple receptacles single or combination. When asked about his responsibility to perform as thorough an investigation as possible, Miller insists that his approach is as per his inspection agreement and his SOP. Adding an air intake vent and then adding a fan in the exhaust ducting will make the room more tolerable for both the transformer(s) and the electricians working in that room. Ground detectors are installed on the control system; If the system is an isolated power system that supplies circuits in health care facilities; or. Where a feeder overcurrent device is not readily accessible, branch-circuit overcurrent devices shall be installed on the load side, shall be mounted . Bonding Connected to establish electrical continuity and conductivity. Broken connectors in a cable linkB. Post author: Post published: June 10, 2022; Post category: printable afl fixture 2022; Then we have: VII. three-wire, three-phaseD. Thus, for voltages higher, A: 12. A: Article 406 of NEC covers the installation of receptacles of both grounded type and non-grounded, A: According to the question we need to Identify and Identify and describe the step-by-step process, A: All components of a photovoltaic system other than the solar panels are included in the balance of, A: Fiber optics is a technology that is connected with the transmission of information as light rays, A: Please find your answer below in step 2, A: Bartleby has policy to solve only first question and if it has subparts then solve only first 3, A: Pin encasings become excessively cumbersome an uneconomical past 33 kV. Code Change Summary: Revised code language on the accessibility requirements for overcurrent devices. A wire, bus, screw, or similar suitable conductor is acceptable as a main bonding. Many inline fuses are not suitable for use as a branch circuit OCPD. A load having the maximum level of current sustained for three hours or more is referred to as a ____ load. The secondary conductors do not extend beyond the enclosure(s) of the Notwithstanding the provisions of paragraph (g)(6)(vi) of this section, the following equipment need not be grounded: Tools likely to be used in wet and conductive locations if supplied through an isolating transformer with an ungrounded secondary of not over 50 volts; and. An appliance branch circuit supplies energy to one or more outlets for the purpose of ____. T(v1,v2,v3)=(v1+v2,v2+v3,v3)T(v_1, v_2,v_3) = (v_1+v_2, v_2+v_3, v_3) One conductor of a single-phase, two-wire system shall be grounded; The neutral conductor of a single-phase, three-wire system shall be grounded; The common conductor of a multiphase system having one wire common to all phases shall be grounded; One phase conductor of a multiphase system where one phase is grounded shall be grounded; and. Article 230.70 (A)(1) (1) Readily Accessible Location. (If these areas are accessible to other than pedestrian traffic, then one of the other conditions applies.). Oddly enough, you will find the underlying concept in NFPA 70E, Standard for Electrical Safety in the Workplace. overcurrent devices do not have to be readily accessible if. A readily accessible disconnecting means shall be provided by which each heating equipment can be isolated from its supply circuit. Nonconductive coatings on transformer enclosures must be removed to ensure electrical continuity, or the termination fittings must be designed to make such removal unnecessary [Sec. A: The solution is provided in the following section: A: Cable Tester- For a grounded system, a grounding electrode conductor shall be used to connect both the equipment grounding conductor and the grounded circuit conductor to the grounding electrode. The ampere rating of this disconnecting means may not be less than the nameplate current rating of the equipment. Over areas, other than public streets, alleys, roads, and driveways, subject to truck traffic. 450 only, a transformer is an individual power transformer (single- or 3-phase,)identified by a single nameplate unless otherwise indicated. T(v1,v2,v3)=(v1+v2,v2+v3,v3). Grounding triad 5. Where connected to a branch circuit supplying two or more receptacles or outlets, receptacle ratings shall conform to the values listed in Table S-5; or, where larger than 50 amperes, the receptacle rating may not be less than the branch-circuit rating. Overcurrent devices do not have to be readily accessible if ____. source such as a lamp or lamps, together with the parts designed to position the light source and to connect it to the power supply. Applying solder to the connectionD. The grounding electrode to which the portable equipment system neutral impedance is connected shall be isolated from and separated in the ground by at least 6.1 m (20.0 ft) from any other system or equipment grounding electrode, and there shall be no direct connection between the grounding electrodes, such as buried pipe, fence, and so forth. B. Over public streets, alleys, roads, and driveways. Therefore, So a telephone occupies a circuit for, A: A circuit breaker is a kind of electrical switch which is used to protect an electrical circuit from, A: A power station is to provide electricity to a huge number of people. Overcurrent Protection Device Overcurrent Protection (Breaker) A branch-circuit overcurrent protection is a device capable of protecting feeders, branch circuits, service equipment between its rated current and its interrupting rating. 450.3(B)]. Branch Circuit Multi-wire D. Although the box contains a multi-wire branch circuit, only one ungrounded (hot) conductor is feeding this duplex receptacle. Where circuit breaker handles on switchboards are operated vertically rather than horizontally or rotationally, the up position of the handle shall be the closed (on) position. Overcurrent devices do not have to be readily accessible if ____. Which of the following would help avoid the choke effect in grounding electrode conductors?A. Common Overcurrent Protection Devices (OCPDs) An overcurrent protection device (OCPD) is a piece of electrical equipment used to protect service, feeder, and branch circuits and equipment from excess current by interrupting the flow of current. The weight supported by any single conduit shall not exceed ____ pounds. Exposed noncurrent-carrying metal parts of fixed equipment that may become energized shall be grounded under any of the following conditions: If within 2.44 m (8 ft) vertically or 1.52 m (5 ft) horizontally of ground or grounded metal objects and subject to employee contact; If located in a wet or damp location and not isolated; If supplied by a metal-clad, metal-sheathed, or grounded metal raceway wiring method; or. Communications conductors alone -- no requirement. It may also include parts to protect the light source ballast or distribute the light. A(n) ____ is an accessory, such as a locknut or bushing, whose function is primarily mechanical, rather than electrical, in nature. Check The Knowledge False Not readily accessible means you dont have to worry about it at all or ever have to service it? Service A. Special Permission AHJ Special permission is the written consent of the authority having Jurisdiction or the AHJ who enforce the NEC and grant variances in the code (building department). Essentially, this Article covers transformers supplying power and lighting loads. If you substitute installation quality for personal safety risk, you could use Figure F.1 of Informative Annex F to identify and correct potential problems with the installation. #10. steve66 said: According to the definition of a branch circuit, it starts at the final overcurrent protection device. Raceway containing branch circuit conductors in concrete, Conduit Body A conduit body is a separate portion of a conduit (tubing) system providing access to the interior of the system through a removable cover at a junction. To catch up on Lorenzo Mari's series on Overcurrent Protection, please visit: National Electrical Code Basics: Overcurrent Protection Part 1 . Aug 12, 2009. Lighting Outlets A. Ground-fault detection and relaying shall be provided to automatically deenergize any high voltage system component that has developed a ground fault. Knowing the NEC rules for transformers is only a start. Enclosures are guarded against employee contact. Table S-4. 1910.304(f)(1)(v) Fuses and circuit breakers shall be so located or shielded that employees will . If that is right, then the in-line fuse (whether or not rated as a branch circuit OCPD) does not establish the beginning of a branch circuit, and the wires upstream (i.e., up to the receptacle, and from the receptacle back to the panel) have not been re-designated as a feeder. A voltmeter will not register a voltage when connected to the same ungrounded (hot) phase. The frame of a vehicle need not be grounded and may serve as the grounding electrode for a system supplied by a generator located on the vehicle under the following conditions: The frame of the generator is bonded to the vehicle frame; The generator supplies only equipment located on the vehicle and cord- and plug-connected equipment through receptacles mounted on the vehicle; The noncurrent-carrying metal parts of equipment and the equipment grounding conductor terminals of the receptacles are bonded to the generator frame; and. For the purposes of Art. conducting. In this example, the receptacle is that outlet. Verified Answer for the question: [Solved] Overcurrent devices do not have to be readily accessible if ____. ." Courtesy ofwww.MikeHolt.com. Accessible (Equipment) Accessible equipment is equipment not guarded by locked doors, elevators, or other. 70 for switch controlled, Concealed Concealed means rendered inaccessible by the structure of finish of a building Conductors in concealed raceways, even though they become accessible by withdrawing them, are still considered concealed. Use and identification of grounded and grounding conductors -, A nongrounding-type receptacle may be replaced with a ground-fault circuit-interrupter-type of receptacle that is marked "No Equipment Ground;" an equipment grounding conductor may not be connected from the ground-fault circuit-interrupter-type receptacle to any outlet supplied from the ground-fault circuit-interrupter receptacle; or. Service conductors installed as open conductors or multiconductor cable without an overall outer jacket shall have a clearance of not less than 914 mm (3.0 ft) from windows that are designed to be opened, doors, porches, balconies, ladders, stairs, fire escapes, and similar locations. Metal enclosures for service equipment shall be grounded. neutral ground strap overcurrent devices do not have to be readily accessible if. Electric equipment is considered to be effectively grounded if it is secured to, and in electrical contact with, a metal rack or structure that is provided for its support and the metal rack or structure is grounded by the method specified for the noncurrent-carrying metal parts of fixed equipment in paragraph (g)(8)(i) of this section. Mandatory rules in the NEC contain the language A cable assembly's ____ conductor can be used as a switch loop (leg) in single-pole, three-way, and four-way switch installations, even though it is an ungrounded (hot) conductor. service disconnect | Mike Holt's Forum Ensure the room is vented either via door vents that cannot be blocked or (preferably) an exhaust vent to the outside. An outlet intended for the direct connection of a lampholder or luminaire is called a. lighting outlet. For each given ppp-series, identify ppp and determine whether the series converges. Notwithstanding the provisions of paragraph (g)(6)(iv) of this section, exposed noncurrent-carrying metal parts of the following types of fixed equipment need not be grounded: Enclosures for switches or circuit breakers used for other than service equipment and accessible to qualified persons only; Electrically heated appliances that are permanently and effectively insulated from ground; Distribution apparatus, such as transformer and capacitor cases, mounted on wooden poles, at a height exceeding 2.44 m (8.0 ft) above ground or grade level; and. Start with "Branch Circuit," not with "Branch Circuit Overprotection Device.". This Note does not require the next size up protection; it permits the next size up. For a better experience, please enable JavaScript in your browser before proceeding. There are a wide variety of supplementary fuses and fuse holders, which have small physical . Answered: Overcurrent devices do not have to be | bartleby Above finished grade or sidewalks, or from any platform or projection from which they might be reached. Ready accessibility to wiring in luminaires is required in all cases required when a building is considered public c.not required dat required if there is a junction bexaby ANS: PTS: REF: Definitions A load having the maximum level of current sustained for three hours or more is referred to as a load. Indicate your answer where indicated. Wire connectors, pigtails, locknuts, bushings, raceway connectors, grounding screws, and equipment bonding jumpers are not factors when calculating ____. in 305 mm (12 in.) Receptacles other than 125 volt, single-phase, 15-, 20-, and 30-ampere receptacles that are not part of the permanent wiring of the building or structure and that are in use by personnel shall have ground-fault circuit-interrupter protection for personnel. Is this in a room with an inswing door? Overcurrent protection shall not exceed _____. These overcurrent devices may not be located where they will be exposed to physical damage or in the vicinity of easily ignitable material. Each service disconnecting means shall simultaneously disconnect all ungrounded conductors. Reason, actually had a debate with a guy that was installing an 'appliance' that say maxium overcurrent rating of 15 amps. The NEC assumes you have already selected a transformer suitable for the load characteristics. The noncurrent-carrying metal parts of equipment and the equipment grounding conductor terminals of the receptacles are bonded to the generator frame. . Neutral Conductor or Point D. The neutral point is the midpoint on a single-phase portion of a 3 wire direct current system. Over commercial areas subject to truck traffic. An ____ is the organization, office, or individual responsible for enforcing the requirements of a code. Both the equipment grounding conductor and the grounding electrode conductor shall be connected to the grounded circuit conductor on the supply side of the service disconnecting means or on the supply side of the system disconnecting means or overcurrent devices if the system is separately derived. Overcurrent Protection Article - InterNACHI Forum Not Readily Accessible Capable of being reached quickly for operation, renewal, or inspections without climbing over or having to remove obstacles. Volume in boxes can be increased by using ____ rings, domed covers, extension rings, or similar items. Transformer top surfaces that are horizontal and readily accessible must be marked to prohibit storage on those surfaces. Conductors and equipment shall be protected from overcurrent in accordance with their ability to safely conduct current. Branch circuit overcurrent definition | Mike Holt's Forum This tab has been removed to allow separate feeds of each outlet. 110.25 [Sec. Signs warning of high voltage shall be posted where unqualified employees might come in contact with live parts. ampacity = Except for motor running overload protection, overcurrent devices may not interrupt the continuity of the grounded conductor unless all conductors of the circuit are opened simultaneously. JavaScript is disabled. If fuses are used for overcurrent protection, a fuse shall be connected in series with each ungrounded conductor; Each protective device shall be capable of detecting and interrupting all values of current that can occur at its location in excess of its trip setting or melting point; The operating time of the protective device, the available short-circuit current, and the conductor used shall be coordinated to prevent damaging or dangerous temperatures in conductors or conductor insulation under short-circuit conditions; and. Select one: A. Accessible (Readily Accessible) Ready accessibility to wiring in luminaires is not required. A disconnecting means shall be provided on the supply side of all fuses in circuits over 150 volts to ground and cartridge fuses in circuits of any voltage where accessible to other than qualified persons so that each individual circuit containing fuses can be independently disconnected from the source of power. Selective coordination 28(7x2)5dx,u=7x2\int 28(7 x-2)^{-5} d x, \quad u=7 x-2
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