The Electrical Contractor Network

ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

Books, Tools and Test Equipment for Electrical and Construction Trades

Page 1 of 2 1 2 >
Topic Options
Rate This Topic
#119806 - 01/27/05 03:39 PM Question on Flagpole Risers
Webmaster Offline


Registered: 10/07/00
Posts: 3142
Loc: NY, USA
(submitted via Joe Tedesco)
Joe, I have an electrical contractor that is using channel for bracing flag poled service risers.  He is cutting the channel on both sides so he can get a bend to meet his needs.  I'm not comfortable with the cutting and bending as I think the strength of the channel is in the design with the sides intact.  Can you run this through for comment by the contractor's network and/or give me any code reference that may apply to this type of installation?

- codeenforcementguy

Tools for Electricians:
#119807 - 01/27/05 03:46 PM Re: Question on Flagpole Risers
DougW Offline

Registered: 06/08/03
Posts: 1083
Loc: North Chicago, IL
That's unbelievable.

The whole idea of the channel is with the three sides intact.

Notching and bending like that will significantly reduce the strength of the strut.

If he wants to do that, use the angle adapters that the various strut mfgs all make... at least they're strength rated.

#119808 - 01/27/05 04:55 PM Re: Question on Flagpole Risers
Bjarney Offline

Registered: 04/10/02
Posts: 2561
Loc: West-Southern Inner-Northeast ...
The minerallacs are equally sleazy.

#119809 - 01/27/05 05:34 PM Re: Question on Flagpole Risers
Northbayec Offline

Registered: 12/16/04
Posts: 26
Loc: San Rafael, CA U.S.A
That looks lovely Inspectors in my area will fail installations if they are not done in a workmanlike manner (NEC 110.12). Is that a permanent installation?

#119810 - 01/27/05 05:50 PM Re: Question on Flagpole Risers
renosteinke Offline
Cat Servant

Registered: 01/22/05
Posts: 5305
Loc: Blue Collar Country
I've installed a number of "mast kits," and I am not really impressed with the design of the factory made solution.
I don't think the NEC discusses this issue, so i took a look at our local utility's specs:

"Periscope structures projecting over 30" above the roof must be braced....Bracing, when required, shall consist of two galvanised steel members installed at approximately 90 degree spread. Minimum size brace shall be 1 1/4 x 1 1/4 x 1/8" galvanised steel angle. Periscope bracing shall be anchored through the sub-roof with minimum 3/8" galvanised carraige bolts."
The accompanying artwork also specifies the bracing to be attached 10" below the weatherhead.

Ironically, the "mast kits" that I've been using rely upon 3/4 RMC for bracing members, and anchor to the roof with lag bolts (that might be 3/8").

Off the cuff, I would guess that this man's solution is as strong as the commercially prepared kit. It is certainly securely anchored to the mast with those multiple mineralacs. It is also quite a bit more expensive than the commercial arrangement I've been using.

#119811 - 01/27/05 05:55 PM Re: Question on Flagpole Risers
Roger Offline

Registered: 05/18/02
Posts: 1779
Loc: N.C.
Amazing, Kendorf, B-line, Super Strut, and the others, all make just about any configuration or ajustable angle fitting that would do this job correctly.


[This message has been edited by Roger (edited 01-27-2005).]

#119812 - 01/27/05 11:24 PM Re: Question on Flagpole Risers
e57 Offline

Registered: 05/27/03
Posts: 2837
Loc: S.F.,CA USA
Creates a "Metal Fatique" point on the strut, a few years in a gental breeze and its gone.
Mark Heller
"Well - I oughta....." -Jackie Gleason

#119813 - 01/28/05 04:02 AM Re: Question on Flagpole Risers
electure Offline


Registered: 12/24/00
Posts: 4226
Loc: Fullerton, CA USA
Anybody that's cut strut with a hacksaw has probably bent the last bit back and forth a few times to break it. This guy's just letting nature do the bending.

Think about it, though. The PoCo uses a piece of small diameter cable to brace their pole, and deems that sufficient.

So, what does it really take?

#119814 - 01/28/05 04:07 PM Re: Question on Flagpole Risers
PCBelarge Offline

Registered: 06/08/03
Posts: 657
Loc: Dobbs Ferry, NY, USA
I have seen worse, at least he made the effort to support the mast. Not that I would pass this though , as Roger has mentioned, the proper fittings are readily available.

Pierre Belarge

#119815 - 01/29/05 04:26 AM Re: Question on Flagpole Risers
walrus Offline

Registered: 07/25/02
Posts: 671
Loc: Bangor Me. USA
why wouldn't you just fold the sides of the channel(strut) in some and then just bend it?? Although less than perfect and easily could have been better and stronger I doubt that would ever break

Page 1 of 2 1 2 >

ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals