Can a service mast be bent?

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Coppersmith

Coppersmith

Senior Member
Location
Tampa, FL, USA
Occupation
Electrical Contractor
Yesterday I repaired a service mast (riser if you prefer). Something, possibly a tree branch, must have fallen on the service drop. The mast was tilted over. The meter hub screws had sheared off and the hub was resting on the conductors. All the straps had ripped out of the wall. And the mast was slightly, but noticeably, bent.

In order to keep the price reasonable, I reused the same mast. I couldn't find any NEC reason that I could not use the mast. When the repair was completed, the mast still had a small, but noticeable, bend. It passed inspection even though the inspector said something about the bend. The power company hooked it back up.

So my question is, is there an NEC reason I missed? Just curious for next time.
 
The fact is that bend is now the weakest link and you made it weaker. It could fail based on whether the mast is strong enough to hold the weight of the incoming wires. Power company is usually the ones that decide that in this area.
 
Dennis Alwon said:
The fact is that bend is now the weakest link and you made it weaker. It could fail based on whether the mast is strong enough to hold the weight of the incoming wires. Power company is usually the ones that decide that in this area.
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I'll agree that a bend is a weak spot, but I'm not sure how I made it weaker. I didn't bend it more. If it makes you feel better, the inspector asked me to add a guy wire (not because of the bend, but because the drop is very long) which I will be doing in a few days. P.S. This broken mast has been like this for a couple of years. I'm surprised it didn't blow up.
 
kwired said:
Outside of using 110.3(A) I don't think so.
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I don't see that at all. It is either suitable or not, and a slightly bent piece of pipe will work just fine. They bend a little all the time just from the weight of the conductors handing off them. Go around town and take a close look at the masts you see. I bet at least 10% of them are bent to some degree.
 
Coppersmith said:
I'll agree that a bend is a weak spot, but I'm not sure how I made it weaker. I didn't bend it more. If it makes you feel better, the inspector asked me to add a guy wire (not because of the bend, but because the drop is very long) which I will be doing in a few days. P.S. This broken mast has been like this for a couple of years. I'm surprised it didn't blow up.
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Was there any evidence that the mast was starting to buckle inward on the inner side of the bend? If so then the mast has been weakened. If not then it may still be quite strong, but guying might be appropriate to stabilize its position.
 
Did you at least point the bed away from the direction of the incoming service this time?

if so, some might admire you for such forward thinking. :)


JAP>
 
jap said:
Did you at least point the [bend] away from the direction of the incoming service this time?
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I thought about it, but it wasn't doable without trying to unscrew the old hub which had multiple layers of paint gluing it to the mast. If I had started down that road, lots of bad things could have happened to make the job a nightmare. The hub was an odd size and I doubted a replacement was quickly available.
 
Any time you bend metal, you stretch some of it. It's been altered outside it's original listing, and should be replaced.
 
480sparky said:
And still comply with 230.28(A)?
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230.28 (A) Strength. The service mast shall be of adequate strength
or be supported by braces or guys to withstand safely the strain
imposed by the service-drop or overhead service conductors.
Hubs intended for use with a conduit that serves as a service
mast shall be identified for use with service-entrance equipment.

Based on my reading, yes. The mast has a slight bend and that may have weakened it slightly but not so much (IMHO) that it is not now of adequate strength as evidenced by the fact that the bent mast has been holding up the service drop for at least two years. But if that statement alone does not satisfy you, you should be happy that a guy is being added which negates the need for adequate strength making the weakening at the bend moot.
 
A bend in a service mast does not make it weak.

I've offset risers to clear gutters more than once.

To my knowledge there's not a rule that this violates.

Jap>
 
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