Overhead UF cable

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garrisonm1

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Maryland
Looked at a job today and running triplex to a outside panel on a wood post. Their is some existing uf cable I'm replacing as we'll running on the same post I will be installing the triplex . My question is can I use the messenger wire in the triplex to support the uf cable or do I need to run a separate messenger wire just for the sun resistant uf cable?
 
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GoldDigger

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Retired PV System Designer
garrisonm1 said:
I understand I can use the uf cable as long as I have a messenger cable but wasn't sure if I can utilize the one on the triplex?
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My first impression is that since the messenger wire in the triplex is part of a 396.2(3) factory-assembled aerial cable, it cannot itself be used as the messenger wire for supporting additional wires under (1), (2) or (4). (The reasoning being that you have no way of attaching directly to the messenger wire rather than attaching to the triplex.
Your term "messenger cable" is not one recognized by the NEC, which only refers to messenger wire.
Also, FWIW, the messenger wire included in the triplex is factory sized to safely support the weight of the triplex, not additional wiring attached to it.

Article 396 does not address the engineering design of a messenger supported cable system, particularly one which is field assembled.
 
kwired

kwired

Electron manager
Location
NE Nebraska
GoldDigger said:
Also, FWIW, the messenger wire included in the triplex is factory sized to safely support the weight of the triplex, not additional wiring attached to it.
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I've had firsthand experience at determining that it usually will support 3-4 inches of ice build up, but it will not support this when tree branches are above and the branches can not take the 3-4 inches of ice. But even then the messenger usually is not what breaks, it is usually an attachment device that fails.
 
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