Service mast height

N

nizak

Senior Member
Is there a maximum height above a roof before a 2” rigid riser needs to have a guy wire / additional support?

I have 42” in my head but don’t know where I got that from.

Thanks
 
roger said:
See 230.28, 342.30(A)(3) and 344.30(A)(3)
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Those just tell us it doesn't need securely fastened within 3 feet of the weather head and don't mention how much riser from the last point of support is permissible. Nothing in NEC really tells us this and is up to designer, installer, AHJ and often the POCO to determine how much strain from the supported service drop may be permissible. This strain is more complicated by weight/length of the drop along with added effects from wind or possible ice build up on the line as well.
 
kwired said:
Those just tell us it doesn't need securely fastened within 3 feet of the weather head and don't mention how much riser from the last point of support is permissible. Nothing in NEC really tells us this.
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Exactly, why do you think I posted it?
 
It’s a POCO requirement, not an NEC issue.

Here in California we have to follow the “Greenbook” from PG&E, and they have several requirements and diagrams for different situations.

I don’t know where you’re at, but I would get in touch with your local poco and/or grab their code book.

I carry a green book in the van along with the CEC, as I use it so often.
 
Doesn’t the power company have a book that they follow? Should be in that then. They keep Telling me that the NEC in their book generally coincides at least as far as like height requirements
 
roger said:
Exactly, why do you think I posted it?
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For OP's benefit and to also say something other than NEC may factor in but isn't necessarily the same everywhere you go.

From NEC perspective said mast must be sufficiently strong enough to take whatever load the service drop may impose on it and there is different conditions in different locations that will factor into what kind of strain may be imposed on that mast. Many northern US locations have some the most extremes. Wind alone is one issue, but throw on a 2 or 3 inch coating of ice on the overhead conductors (it happens) and you have even more added weight and strength of supporting items gets even more compromised if the wind should pick up.
 
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