All right, I admit it, I was wrong ... there IS a reference to the NEC
. BTW, who's SCE?
Now, let's look at exactly what both the local (SPPCo) specs, and the NEC have to say about the periscope mast.
The PoCo spec says "minimum 2" rigid steel." That's it. There is also considerable detail as to bracing, etc., not included in the NEC. I've attached a copy.
The NEC, regarding "Service Masts as Supports," simply says "it shall be of adequate strength." Further on, it continues "Where raceway-type service masts are used, all raceway fittings shall be identified for use with service masts."
Now, the wording of all those citations seems to suggest that there is no requirement to use ant particular material - that the mast can be made in nearly any manner, including by using conduit. There is a notable failure to use words such as "listed," or even specific trade terms, such as 'rigid metallic conduit.'
Lest we forget from whence we came, this pic shows a house here that has already had one service upgrade:
Please note that the original mast was all wood; the steel mast is 1 1/4 RMC (I assume), and was replaced (by me) with the current 2" RMC.
I apologize for the size of the next file, but I wanted everyone to be able to print off a good copy. This is one page -of about five- of the local PoCo specs regarding overhead residential service drops.
As outrageous as it may seem to use water pipe, the amount of weakening that may be caused by coupling two pieces together, rather than using a single piece of pipe, is not to be casually ignored. 100 ft. cable drop, 80mph winds, inclines and other reasons requiring a substantial projection above the roof .... all can require the 'standard' methods be reviewed.
For example ... that 40" maximum projection above the roof shown in the PoCo specs ... I was REQUIRED to exceed that by clearance requirements over an intervening building. Naturally, that mast required some substantial bracing.
Again, let's return to the very basics of the NEC (as outlined in Article 90). 90.4 make clear that it is the responsibility of the AHJ to interpret the rules, approve materials and methods, etc. "One size fits all" works in codebooks just about as well as it does in clothing .... that is, it doesn't - and this discussion underscores that point.