344.30

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chris kennedy

chris kennedy

Senior Member
Location
Miami Fla.
Occupation
60 yr old tool twisting electrician
I was asked to look at a service in need of repair today. Two 3?" RMC risers were supported by unistrut and the strut was anchored with what appears to be two 3-16ths toggle bolts into hollow cells in concrete block. This happened Saturday night and the building still has power.

344.30 compliant?


Adamsservice001.jpg



Adamsservice002.jpg
 
That should never have passed inspection to get energized in the first place. I don't see any support remotely close to the POA. How long is the service drop?




All that, plus, where's Als' shovel?
 
Far too commonplace.
(One of the POCOs in my area allows service masts to be fastened to Double-Wides..I'm waiting in the next ice storm :))
 
OK, on closer examination, it appears the pipes themselves are not used for the POA. At least I don't see any evidence of it. So the POA must have been to the building instead.

Any details on the actual POA? My guess is that is what failed first, and the drop took the risers down as colateral damage.
 
chris kennedy said:
Two 3?" RMC risers were supported by unistrut and the strut was anchored with what appears to be two 3-16ths toggle bolts into hollow cells in concrete block.
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I'd definitely upgrade to two 1/4" toggles.:cool:

In all seriousness, what's your plan now? I'd probably use 3/8" allthread and through-bolt through the block and use square strut washers on the inside of the building. As well as more strut closer to the weatherheads if possible.
 
At a minimum it should of had two pairs of support. Maybe even 3. I see that on a lot of shopping centers here.
 
The second picture shows an anchor point on the building seperate from the pipes. At the bottom of the picture, you can see the cable attaced to the grounded conductor. I bet an overheight tractor trailer took this down.
 
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The problem, IMO, is the POA. Once the point of attachment gives way then everything else usually follows. I don't know how long that drop is but I bet it had a tremendous amount of tension on it.

I am not sure whether the rmc should be expected to carry the weight once the POA gives out. I see this in residential services often. Tree limb pulls the poa out and the entire PVC riser comes out also.

I have seen a riser thru the roof where the poa is the 2"rmc and the entire pipe would bend when a tree limb comes down on the overhead lines.
 
480sparky said:
How long is the service drop?
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About 30', looks like 4/0.

1793 said:
Did they use unistrut and two hole straps?, photo #2
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Yup, my guess is it wasn't very pretty to begin with.

1793 said:
Do you know what brought this down?
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Gravity.

Cow said:
In all seriousness, what's your plan now?
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3 sets of straps on unistrut anchored by 2 1/8 tapcons.

480sparky said:
Anyone see any ground rods?:cool:

Meyers hubs? :cool:
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Meyers hubs are existing, new GES to be installed tomorrow.

1793 said:
New construction? CEE?
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No sir, appears to be about 20 years old.

480sparky said:
OK, on closer examination, it appears the pipes themselves are not used for the POA. At least I don't see any evidence of it. So the POA must have been to the building instead.

Any details on the actual POA? My guess is that is what failed first, and the drop took the risers down as colateral damage.
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Look at picture 2 to the left at the very top. Between the two crooked risers is what is left of a ceramic POA. There is a little scratch on the POCO pole and I was told some evidence of a busted tail light, so I'm guessing you are correct.
 
chris kennedy said:
............There is a little scratch on the POCO pole and I was told some evidence of a busted tail light, so I'm guessing you are correct.
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So just a 'bump' on the POCO pole brought this down? And that pole is still standing?
Geez, a strong wind would have done the same thing then.
 
480sparky said:
So just a 'bump' on the POCO pole brought this down? And that pole is still standing?
Geez, a strong wind would have done the same thing then.
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Yeah, I don't buy the car backing into the pole. Should have taken a couple pictures of that. New pole with new asphalt around it and no evidence of movement. The 'scratch' to me looked to low to be caused by a car, looks like an install scar. I didn't see the tail light debris, just heard about it. I agree that the way the risers are laying it appears the POA failed first.
 
chris kennedy said:
Yeah, I don't buy the car backing into the pole. Should have taken a couple pictures of that. New pole with new asphalt around it and no evidence of movement. The 'scratch' to me looked to low to be caused by a car, looks like an install scar. I didn't see the tail light debris, just heard about it. I agree that the way the risers are laying it appears the POA failed first.
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Still, even 30' of drop doesn't put THAT much pressure, even on a ceramic POA. Looks lit it just opened up, not pulled out.

If the pipes were supported properly, they most likely would have not fallen. Shorting out in the weatherheads might have been a different story, however.
 
480sparky said:
Still, even 30' of drop doesn't put THAT much pressure, even on a ceramic POA. Looks lit it just opened up, not pulled out.

If the pipes were supported properly, they most likely would have not fallen. Shorting out in the weatherheads might have been a different story, however.
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Could be when the POA gave way and due to the distance from the POA to the Weatherhead, the slack jerked the riser(s) off the wall.
 
1793 said:
Could be when the POA gave way and due to the distance from the POA to the Weatherhead, the slack jerked the riser(s) off the wall.
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I just can't imagine 30' of service drop could cause a ceramic Johnny Ball to fail. Either it was defective, or there was a lot of pressure put on the service drop.... I'd look for a sharp angle in the bare neutral. If a tall truck caught it, the steel in the ACSR would retain that bend.
 
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