The NEC does permit tap conductors to have overcurrent protection set at a value that greatly exceeds the ampacity of the conductors, but this is only permitted under specific conditions outlined in 240.21. Before we get into the details of 240.21, you must understand that a tap conductor isn't permitted to supply another tap conductor.

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2004-01-05 · Author’s Comment: This definition is needed in the application of the requirements for Branch Circuit Taps [210.19(D) and ‘Feeder Tap Conductors [240.21(B)]. The text was slightly revised to clarify that service conductors are not to be considered tap conductors. For these requirements, NEC 240.21(C) shall apply for different scenarios depending on the length of the secondary conductors. For example, a facility is equipped with a 75-kVA transformer with a 480 V, 3-phase, 3-wire primary and 120/208V, 3-phase, 4-wire secondary. Thanks to the NEC Connect for sharing Table 250.102(C)(1) and Section 240.21(A)&(B). Table 250.102(C)(1) Grounded Conductor, Main Bonding Jumper, System Bonding Jumper, and Supply-Side Bonding Jumper for Alternating-Current Systems.

Over current 240.21 Location in Circuit. Overcurrent Protection shall be provided in each ungrounded circuit conductor and shall be located at the point where the conductors 2. In applications of 600 V or less, overcurrent protection is typically located at the load end of the field installed conductors, NEC 240.21(C). (or Part VIII of Article (NEC 240.21 B). 18. Provide a note stating that any conductors exposed to sunlight shall be listed as sunlight resistant. (NEC 300.6 C1, 310.8 D). Master The NEC Enjoy this graphic on Transformer Secondary Conductor rules in 240.21(C)(6).

Click to Enlarge The tap conductor ampacity cannot be less than the rating of the equipment containing an overcurrent device supplied by the tap conductors or not less than the rating of the overcurrent protective device at the termination of the tap conductors. 240.21(B) Feeder Taps. Conductors shall be permitted to be tapped, without overcurrent protection at the tap, to a feeder as specified in 240.21(B)(1) through (B)(5).

NEC 240.21 is about the location of the overcurrent device, not the need for it. I bring up these three points because it’s easy to become so involved in the “location” rules (240.21) that you may misinterpret them into meaning that secondary conductor overcurrent protection is not required at all!

Thanks to the NEC Connect for sharing Table 250.102(C)(1) and Section 240.21(A)&(B). Table 250.102(C)(1) Grounded Conductor, Main Bonding Jumper, System Bonding Jumper, and Supply-Side Bonding Jumper for Alternating-Current Systems. Click below to receive the free PDF and a supporting video excerpt from the NEC Training.

New Article 409 for the 2005 NEC requires that either a single OCPD be located ahead of an Industrial Control Panel, or a Main CB (i.e., ONE CB) be located within the Industrial Control Panel. But 409.21 states that this protection shall be provided in accordance with 240.21 Parts I, II, and IX.

The tap shall be permitted at any point on the load side of the feeder overcurrent protective device. Section 240.4(B) shall not be permitted for tap conductors. NEC 2014 edition electrical code tap rules The NEC article dealing with overcurrent protection of feeder taps is article 240.21(B). These rules are often referred to as the NEC “tap rules”. There are five tap rules related to feeder circuit taps: − Taps Not Over 3 m (10 ft.) Long − Taps Not Over 7.5 m (25 ft.) Long Visit http://www.MikeHolt.com/examprep to explore our product catalog. Mike Holt Enterprises offers comprehensive electrical exam prep materials delivered in Se hela listan på ecmweb.com 4. Location of overcurrent protection NEC 240.21 basically says that – conductors must have overcurrent protection at their point of supply except as permitted in NEC 240.21 (A) through (H).

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2020-06-01 2019-11-06 2015-12-11 For more information, call 888.NEC.CODE (632.2633), or Rule 5 240.21 Overcurrent Protection Location in Circuit..

2. NEC 430.53 (B) addresses installations where the smallest This section consists of NEC free online practice tests These tests helps in preparing for Journeyman and Master electrician License exams Enjoy free tests.. 240.21(B)(1) Feeder Taps Not over 3 m (10 ft) Long.
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In 240.21(A) Branch-Circuit Conductors, we find a method of performing taps for branch circuits, but note that you are referred back to Article 210.19 and 210.20 for the exact applications. In subsection (B) we start to deal with the Feeder Taps, which are further broken down to five conditions.

Protection of Flexible Cords, Flexible Cables, and Fixture Wires. 240.6. Taps can be made at conductors without overcurrent protection at the tap as noted in section 240.21(B)(1) through (5) below. 2017-10-04 NEC 240.21, with some exceptions, requires overcurrent protection in each ungrounded conductor to be located where the conductors connect to the load.

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NEC 240.21(B)(2) requires the conductors to terminate in an overcurrent device. 8. Is a service receptacle required in a furnace room located in the middle of a

NEC … Per NEC 240.21, overcurrent protection shall be provided in each ungrounded circuit conductor and shall be located at the point where the conductors receive their supply except as specified in 240.21… NEC Section 240-21(c)(1) states that overcurrent devices are not required on the secondary of a single phase 2-wire or three phase, three wire, delta-delta transformer to provide conductor protection where all of the following are met: (1) The transformer is protected in accordance Download this FREE PDF of 240.21(A) and 240.21(B) and get the most-up-to-date information regarding feeder taps directly from the 2014 NEC® Handbook.