ryan_618
Senior Member
- Location
- Salt Lake City, Utah
I was always led to beleive that you simply cut off the small bonding strip in type AC cable. Upon further investigation, it appears that I am wrong.
Here is an E-mail I sent to a major manufacturer of both AC and MC Cables, and his reply:
Response:
Here is an E-mail I sent to a major manufacturer of both AC and MC Cables, and his reply:
When terminating type AC cable, your instructions specify that you must bend the bonding strip back over the cable armor. Why is that? It seems to me that the purpose of the bonding strip is to be in intimate contact with the cable armor, therefore providing an effective ground fault current path. With this said, once the bonding strip leaves the cable armor, it is doing nothing. Why would you need to wrap the bonding wire back over the cable armor, when the cable armor is already in contact with the bonding strip inside of it?
Response:
Dear Mr. Jackson:
Yes, you are correct. However, in the absence of any guidance from the NEC or the U.L. standard that the cable is manufactured to, we are left with best trade practices. When we first published installation guidance for armored cables we worked with James Stallcup. With his assistance we polled the electrical community and gathered information on the best trade practices used in the field for terminating the bond strip in Type AC cables. Overwhelmingly the responses all lead to the bond strip being "displayed" on the outside of the cable armor because the electrical inspectors demanded to see it for themselves during the inspection process. Apparently by being able to see the bonding strip, they could quickly ascertain that the proper cable type had been used. Therefore, when we began printing our installation publications we illustrated what we had learned.
But again, you are correct. Through the manufacturing process the bonding strip is placed tight up against the interior of the cable armor, in complete contact from end to end, thereby providing the armor/bond wire combination with a low impedance ground fault capability, which is tested prior to being put into the marketplace for use. Cutting the bond wire off at the end of the cable armor, although not nationally recognized as a best trade practice, would not impact the viability of the grounding means of the armor/bond wire combination. Further, traditionally the bond wire holds the mandated anti-short bushing in place.
I trust this information has been helpful in understanding the history of terminating Type AC cables.
Please tell Mike that I send my hearty greetings his way.
Marilou Newell
National Marketing and Technical Services Manager
AFC Cable Systems, Inc.