IMO 422.11 (E) 3 permits him to do this WITHOUT the fuse. Overcurrent devices shall be readily accessible to each employee or authorized building management personnel. 5. A grounding electrode is a(n) ____ object that establishes a direct connection to earth. This record shall be kept by means of logs, color coding, or other effective means and shall be maintained until replaced by a more current record. Branch circuits are divided into four categories: Appliance, General purpose, Individual, and Multi-wire. "I have learned, in whatsoever STATE I am, therewi, http://www.usahardware.com/inet/shop/item/30550/icn/20-068163/bussman/bp_sru.htm. Ground is defined as earth. k=13k51. First week only $4.99! 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.) maximum fuse or circuit breaker size =, 4.a. Over public streets, alleys, roads, and driveways. Holes must be bored so that the edge of the hole is at least ____. Open conductors, open multiconductor cables, and service-drop conductors of not over 600 volts, nominal, shall conform to the minimum clearances specified in Table S-6. If a vented dry-type transformer is installed in an equipment room with a door: A terminal bar for equipment grounding conductors (EGCs), system bonding jumpers, supply-side bonding jumpers, and grounding electrode conductors (GECs) must be installed and bonded inside the transformer enclosure [Sec. 250.12]. Handles or levers of circuit breakers, and similar parts that may move suddenly in such a way that persons in the vicinity are likely to be injured by being struck by them, shall be guarded or isolated. Nec Flashcards | Quizlet Which agency is responsible for the maintenance and publication of the NEC ? A circuit breaker with a slash rating, such as 120/240 V or 480Y/277 V, may only be installed in a circuit where the nominal voltage of any conductor to ground does not exceed the lower of the two values of the circuit breaker's voltage rating and the nominal voltage between any two conductors does not exceed the higher value of the circuit breaker's voltage rating. Occupational Safety & Health Administration. The branch circuit wiring method shall include or provide an equipment grounding conductor to which the grounding contacts of the receptacle or cord connector shall be connected. Box calculations for 4 AWG and larger conductors (under 600 volts) are performed based on the ____. All noncurrent-carrying metal parts of portable equipment and fixed equipment, including their associated fences, housings, enclosures, and supporting structures, shall be grounded. Overcurrent protection simply means a fuse, breaker, or fusible link is used to protect the equipment . Service-entrance conductors installed as open wires shall be guarded to make them accessible only to qualified persons. LOCATED ADJACENT TO THE EQUIPMENT WHERE ACCESS IS ACHIEVED BY THE USE OF PORTABLE MEANS, C.THE TOTAL LOAD OF THE ADJACENT CIRCUIT DOES NOT EXCEED LOCAL STANDARDS, D.THE DISCONNECTING MEANS IS READILY ACCESSIBLE. https://www.facebook.com/ElectricalConstructionMaintenanceMagazine, https://www.linkedin.com/company/electrical-construction-maintenance/. ", The continuous ampere rating of a fuse may not exceed three times the ampacity of the conductors. National Firefighters Association (NFA) Underwriter's Laboratory (UL) National Fire Protection Association (NFPA) 1 ANS: PTS: Electrical Code REF: The National 9. equipment grounding terminal bus NEC Requirements for Conductor Material Types and Sizing Requirements, Electrical Troubleshooting Quiz July 19, 2022, NEC Requirements for Overvoltage Protection, EC&M Tech Talk Video Medium-Voltage Conductors and Cable, Monthly Quiz: Grounding and Bonding Connections. Two exceptions to the make readily accessible rule are noted in Sec. According to the definition of a branch circuit, it starts at the final overcurrent protection device. According to Note 1 of Table 450.3(B), transformers having a primary current rating of 9A or more are permitted to use the next size up rule when 125% of the primary current doesnt correspond to the standard rating of a fuse or nonadjustable circuit breaker listed in Sec. C. A single conduit is not permitted as sole support for an FS-type or weatherproof junction box. Knowing the NEC rules for transformers is only a start. A reduction in clearance to 914 mm (3.0 ft) is permitted where the voltage between conductors does not exceed 300 and the roof has a slope of 102 mm (4 in.) Busbars shall have an ampere rating not less than the overcurrent device supplying the feeder . Nonmetallic-sheathed cable not fastened to the box must be secured within ____ in. The Code does not completely address this issue. 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. Exterior protected locations under canopies, roofs, porches, and similar sites are considered damp locations. three-wire, three-phaseD. Over commercial areas subject to truck traffic. If you can move this dresser, and it has a cover plate its accessible. The neutral conductor of a multiphase system in which one phase is used as a neutral conductor shall be grounded. A: Equipment Grounding Conductor (EGC) A conductive path that 's a component of a decent ground-fault, A: It's critical to ground-fault protection of equipment system functionality that the ground, A: A power cable is an electrical cable that is made up of one or more electrical conductors that are, A: Communication System : Readily Accessible | Mike Holt's Forum The full form of the acronym, MCCB, is Miniature Case. Receptacles connected to circuits having different voltages, frequencies, or types of current (ac or dc) on the same premises shall be of such design that the attachment plugs used on these circuits are not interchangeable. A violinist places her finger so that the vibrating section of a 1.0 g/m string has a length of 30 cm, then she draws her bow across it. Metal car frames supported by metal hoisting cables attached to or running over metal sheaves or drums of grounded elevator machines are also considered to be effectively grounded. Cable installed under a building must be ____ unless the wiring method is Type MC or Type MI cable that is identified for direct burial. 450.3(B)]. Proper transformer selection is an important part of preventing transformers from overheating. One of the most common applications for "readily accessible" occurs in 240.24(A), in which the NEC states that overcurrent devices must be readily accessible and 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 6 feet, 7 inches above the floor . Metal enclosures for conductors added to existing installations of open wire, knob-and-tube wiring, and nonmetallic-sheathed cable need not be grounded if all of the following conditions are met: Runs are less than 7.62 meters (25.0 ft); Enclosures are free from probable contact with ground, grounded metal, metal laths, or other conductive materials; and. Means shall be provided to disconnect all conductors in a building or other structure from the service-entrance conductors. Replacement of receptacles shall comply with the following requirements: Where a grounding means exists in the receptacle enclosure or a grounding conductor is installed, grounding-type receptacles shall be used and shall be connected to the grounding means or conductor; Ground-fault circuit-interrupter protected receptacles shall be provided where replacements are made at receptacle outlets that are required to be so protected elsewhere in this subpart; and. Listed equipment protected by a system of double insulation, or its equivalent, and distinctively marked as such. 15A for 14 AWG copper, 20A for 12 AWG copper, and 30A for 10 AWG copper. Notice the bonding jumper must be made of copper or other corrosion-resistant material. Overcurrent devices do not have to be readily accessible if ____. Bonding means that everything is connected or conductivity of the electron through wires. Select one: I think you need to back up a few paragraphs, within article 100. a. Service Equipment A. IMO, if you stick a fuse within a cord, and plug that cord into a receptacle outlet, you are outside the premises wiring system. The article 100 definition of a branch circuit ends at an outlet. Based on the 2020 NEC. National Electrical Code Basics: Overcurrent Protection Part 5 A grounded conductor is a system or circuit conductor that is intentionally grounded. Branch Circuit Multi-wire A. Not be located where they will be in the . Article 100 Electrical Code Definitions Understanding Code Accessible Outlet A point in a wiring system from which current is taken to supply utilization equipment is known as an outlet. Overcurrent devices do not have to be readily accessible if ____. Accessible (Equipment) Accessible equipment is equipment not guarded by locked doors, elevators, or other. 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. They can also be installed in panelboards or control boards that are in rooms or enclosures free from dampness, easily ignitable material and accessible only to qualified personnel. According to that same definition, the branch circuit ends at an outlet. The terminals are rated 75C (Fig. four-wire, single-phase. The long-time trip element setting of a breaker or the minimum trip setting of an electronically actuated fuse may not exceed six times the ampacity of the conductor. A separately derived system is a premises wiring system whose power is derived from a source of electric energy or equipment other than a service. An AFCI is basically like a GFCI but it will protect the entire circuit from the breaker and back. Also, suggest that card access to the room be granted only to people who fit OSHAs definition of a qualified worker per the equipment inside the room. Step 2: Determine the primary overcurrent protection rating [Sec. It is a system in which exchange the information between two node or points., A: Delay skew is the difference between the propagation delay on the fastest and slowest pairs in a UTP, A: Although, Enclosures are guarded against employee contact. B. Fuses and circuit breakers shall be so located or shielded that employees will not be burned or otherwise injured by their operation. Notice the language is accessible to qualified personnel. This in no way inhibits making transformers inaccessible to unqualified personnel. A major concern with transformers is preventing overheating. If the system is a high-impedance grounded neutral system in which a grounding impedance, usually a resistor, limits the ground-fault current to a low value for 3-phase ac systems of 480 volts to 1000 volts provided all of the following conditions are met: Ground detectors are installed on the system; and. (This category includes conditions covered under the 3.05-m (10.0-ft) category where the voltage exceeds 300 V.). A: The solution is provided in the following section: A: Cable Tester- Ground detectors are installed on the control system; If the system is an isolated power system that supplies circuits in health care facilities; or. (If these areas are accessible to other than pedestrian traffic, then one of the other conditions applies.). The frame of a portable generator need not be grounded and may serve as the grounding electrode for a system supplied by the generator under the following conditions: The generator supplies only equipment mounted on the generator or cord- and plug-connected equipment through receptacles mounted on the generator, or both; and. See 210. Start with "Branch Circuit," not with "Branch Circuit Overprotection Device.". Access to Overcurrent Protective Devices | UpCodes Receptacle A. Installing a main bonding jumperB. LOCATED WITHIN A GROUNDED JUNCTION BOX. What might block airflow? termination. Readily Accessible, Jam Factor and More - Electrical Contractor Magazine You can never fix power quality problems by introducing grounding or bonding errors at the transformer or anywhere else. Overcurrent Devices Do Not Have to Be Readily Accessible If (This category includes conditions covered under the 3.05-m (10.0-ft) category where the voltage exceeds 150 V.). 450.10(A)]. Between the three-phase line and the disconnect switch. False. However, receptacles of cord- and plug-connected arc welders may have ampere ratings not less than the minimum branch-circuit conductor ampacity. Overcurrent devices do not have to be readily accessible if located within anded jacobs k. the connecting means is readily accessible the total of the conceitdees of wood local andards Located at the equipmenl where excess is achieved by the we of poetic ANS: PTS: REF: Definitions 3. The grounding contacts of receptacles and cord connectors shall be grounded by connection to the equipment grounding conductor of the circuit supplying the receptacle or cord connector. 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. A feeder consists of all circuit conductors located between the service equipment, the source of a separately derived system, or other power supply source and the final branchcircuit overcurrent device. located adjacent to the equipment where access is achieved by the use of portable means. Bonding Jumper (Main) An Equipment bonding jumper is the connection between two or more portions of the equipment grounding conductor. 2023 Endeavor Business Media, LLC. Electrical metallic tubing must not be ____. A load having the maximum level of current sustained for three hours or more is referred to as a ____ load. The main bonding jumper is connection at the service between the grounded circuit conductor and the equipment grounding conductor. A compartment or chamber having one or more attached air ducts and forming the distribution system is known as a plenum. It has no direct connection from circuit conductors. of its overcurrent devices protecting branch circuits of 30A or less, shall have individual protection on the line side not greater than the rating of the . 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. When any element of this branch circuit is replaced, the entire branch circuit shall use an equipment grounding conductor that complies with all other provisions of paragraph (g) of this section. Each service disconnecting means shall be suitable for the prevailing conditions. 102. Note 1 of Table 450.3(B) says that if 125% of the primary current does not correspond to a standard rating of an overcurrent protective device [Sec. However, a current-limiting device without a disconnecting means is permitted on the supply side of the service disconnecting means. Luminaire A luminaire is a complete lighting unit consisting of a light source such as a lamp or lamps, together with the parts designed to position the light source and connect it to the power supply. B. Always install transformers per the manufacturers instructions and ensure transformer ventilating openings are not blocked by walls or other obstructions [Sec. four-wire, three-phaseB. overcurrent devices do not have to be readily accessible if 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. Example: A service disconnecting means must be readily accessible or near the entry point of the service conductor. Dry locations are those not normally subject to moisture except on a temporary basis such as a building under Construction NEC. Neutral Conductor or Point C. The neutral point is the midpoint on a single-phase portion of a 3 phase Delta System. It can apply to industrial motor as well that run facilities, Device A unit of an electrical system that carries or controls electrical energy as its principal function is known as a device. Stumped by the Code? Exposed noncurrent-carrying metal parts of cord- and plug-connected equipment that may become energized shall be grounded under any of the following conditions: If in hazardous (classified) locations (see 1910.307); If operated at over 150 volts to ground, except for guarded motors and metal frames of electrically heated appliances if the appliance frames are permanently and effectively insulated from ground; If the equipment is of the following types: Refrigerators, freezers, and air conditioners; Clothes-washing, clothes-drying, and dishwashing machines, sump pumps, and electric aquarium equipment; Hand-held motor-operated tools, stationary and fixed motor-operated tools, and light industrial motor-operated tools; Motor-operated appliances of the following types: hedge clippers, lawn mowers, snow blowers, and wet scrubbers; Cord- and plug-connected appliances used in damp or wet locations, or by employees standing on the ground or on metal floors or working inside of metal tanks or boilers; Portable and mobile X-ray and associated equipment; Tools likely to be used in wet and conductive locations; and. Home > 2022 > June > 10 > Uncategorized > overcurrent devices do not have to be readily accessible if. Conductors: With junction boxes of recessed luminaires can be accessed by removing part of the luminaire. Tenant access to panel | Mike Holt's Forum Indicate your answer where indicated. These overcurrent devices may not be located where they will be exposed to physical damage or in the vicinity of easily ignitable material. Tests performed as required in paragraph (b)(3)(ii)(C) of this section shall be recorded. Article 450 then takes you to the next logical step providing overcurrent protection and the proper connections. 240.4(B). Bonding Jumper (Main) When metal parts are required to be electrically connected, a reliable conductor (Bonding Jumper) is installed, thereby guaranteeing electrical conductivity. However, equipment that is guarded by location and isolated from ground need not be grounded. These overcurrent devices may not be located where they will be exposed to physical damage or in the vicinity of easily ignitable material. In addition, a single disconnecting means is permitted on the supply side of more than one set of fuses as permitted by the exception in 1910.305(j)(4)(vi) for group operation of motors, and a single disconnecting means is permitted for fixed electric space-heating equipment. Exposed noncurrent-carrying metal parts of portable and mobile equipment shall be connected by an equipment grounding conductor to the point at which the system neutral impedance is grounded. A: The correct option along with the explanation is provided in the following section. 240.24(A) Accessibility. - ElectricalLicenseRenewal.com 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. 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. In the 2014 NEC, the definition of readily accessible in Article 100 was revised to make it clear that something is not readily accessible if a tool is needed to gain access to it. Receptacles and cord connectors having grounding contacts shall have those contacts effectively grounded except for receptacles mounted on portable and vehicle-mounted generators in accordance with paragraph (g)(3) of this section and replacement receptacles installed in accordance with paragraph (b)(2)(iv) of this section. PDF Equipment Protection - Eaton What is the angle pull for a raceway in the vertical dimension where the trade size of the largest raceway is 4 and the sum of the other raceways in the same row on the same wall is 5? 110.25 [Sec. 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. T/F. 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. Selective coordination Branch Circuits A. Circuit breakers shall clearly indicate whether they are in the open (off) or closed (on) position. These materials are provided by Mike Holt Enterprises in Leesburg, Fla. To view Code training materials offered by this company, visit www.mikeholt.com/code. fire protection system.D. 1910.306 - Occupational Safety and Health Administration 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. Check The Knowledge False A grounded conductor is a jumper to the main box on a feeder tube. For the purposes of Art. Branch Circuit The circuit conductors found between a circuits final overcurrent protective device (breaker) and the circuits outlet is called a branch circuit. What can installation records be used to determine while servicing equipment?A. Alternatively, you can also use a properly rated safety switch. 450 only, a transformer is an individual power transformer (single- or 3-phase,)identified by a single nameplate unless otherwise indicated. Cables running horizontally (or diagonally) are considered supported and secured when passing through a(n) ____. A conductor used as an equipment grounding conductor shall be identifiable and distinguishable from all other conductors. Over commercial areas subject to pedestrian traffic or to vehicular traffic other than truck traffic. However, conductors that run above the top level of a window may be less than 914 mm (3.0 ft) from the window. Branch Circuit Multi-wire D. Although the box contains a multi-wire branch circuit, only one ungrounded (hot) conductor is feeding this duplex receptacle. You will have to check the listing of the fuse and fuse holder. For installations made before April 16, 1981, electric equipment is also considered to be effectively grounded if it is secured to, and in metallic contact with, the grounded structural metal frame of a building. 450.3(B)]. Basically, ______receptacles are required to be installed if an equipment grounding conductor is available at the outlet where the receptacle is located. Metal enclosures for service equipment shall be grounded. Readily Accessible - Electrical Contractor Magazine A grounding electrode is a(n) ____ object that establishes a direct connection to earth. Branch circuits are divided into four categories: Appliance, General purpose, Individual, and Multi-wire. For example, most of the general tips for setting it in place are not found in the NEC. 19. If a delta-connected high voltage system is used to supply the equipment, a system neutral shall be derived. Appliance Utilization equipment of a commonly built-in standard, installed as a unit such as AC, or a stove. Vertical clearance of final spans above, or within 914 mm (3.0 ft) measured horizontally of, platforms, projections, or surfaces from which they might be reached shall be maintained in accordance with paragraph (c)(2) of this section. LOCATED WITHIN A GROUNDED JUNCTION BOX B. There was general agreement that climbing over or under something would render equipment accessible but not readily accessible. 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. For an ungrounded separately derived system, the equipment grounding conductor shall be connected to the grounding electrode conductor at, or ahead of, the system disconnecting means or overcurrent devices. 1. contiguous. A receptacle outlet shall be installed wherever flexible cords with attachment plugs are used. Overcurrent devices shall be readily accessible to each employee or authorized building management personnel. Rigid metal conduit (RMC) is a raceway of ____. Over residential property and driveways. 4 A through D for additional requirements. Note: Please do not handwritten. When any element of this branch circuit is replaced, the entire branch circuit shall use an equipment grounding conductor that complies with all other provisions of paragraph (g) of this section. Article 230: Services Part 1 | EC&M Not Readily Accessible Capable of being reached quickly for operation, renewal, or inspections without climbing over or having to remove obstacles. Select one: A. Article 450 of the National Electrical Code (NEC) opens by saying, This article covers the installation of all transformers. Then it lists eight exceptions. If someone props the door open (for example, because the room is hot and they need to work in there), and the inswing door blocks the vent of a transformer, that transformer is more likely to overheat.