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Radio equipment that uses a screw-type fastener to bond or attach the grounding conductor to the antenna assembly

Posted By Tom Moore, Saturday, September 01, 2012
Updated: Tuesday, September 18, 2012

Question

We have some radio equipment that uses a screw-type fastener to bond or attach the grounding conductor to the antenna assembly. Can this screw be any ordinary screw, or does it need to be a "listed” screw meeting the requirements of 250.70 or, perhaps, 250.8? Does the screw need to be "green” in finish? Do the grounding and bonding rules in Article 250 apply to radio and television equipment? Or is Article 810 the only applicable rules that would apply? DB

Answer

Thank you for your correspondence. The question presented is frequently discussed by many with diverse results. Radio equipment as referenced in the question falls under the scope of Article 810 of the NEC.

We first need to point out that the term grounding conductor as referenced in the question and used in previous editions of the NEC has been revised to three more appropriate terms: grounding electrode conductor, bonding jumper, or bonding conductor. CMP-16 accepted these revisions throughout Article 770 and all Chapter 8 articles to provide consistency and correlation with defined grounding and bonding terms in Article 100, and to avoid the use of an undefined term in the communications articles.

Let’s begin with the first part of your question. Section 250.70 does apply for the connection to grounding electrodes as referenced in 810.21(K). If I understand the question correctly, we are referring to the grounding electrode conductor or bonding conductor termination to the equipment. Section 810.21 is silent as to the requirements for connection of the grounding electrode or bonding conductor to the equipment; therefore, the listing requirements of the radio equipment need to be followed.

As for the screw terminal, Chapter 8 has no requirements that would require the screw to be identified by a green color.

In the third part of the question dealing with the application of grounding and bonding rules of Article 250, we need to review the code arrangement in 90.3. The second paragraph of 90.3 points out that Chapter 8 is basically a stand-alone chapter, and that Chapters 1 through 7 only apply where specifically referenced in Chapter 8. One example is the reference to 250.70 in 800.21(K) and discussed above.

Tom Moore
IAEI Representative, Chairman-CMP-16

Tags:  Focus on the Code  September-October 2012 

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