Riser Problem

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malty

Member
I've got a customer that wants to move the meter socket and service conductors to the side of the building and off the front of the house.To do this I've got to use a 2 in ridgid riser above the roof to to keep in line with poco's pole. It's a two story house so if I use a ten ft length at the top for support and install the service bracket at the required height I still have to make up approx four ft from the coupling to the meter hub. If I use the ten ft length on the meter hub it puts the coupling too close to the roof line. If I use a 4 ft cut piece of PVC I'll lose the bond between the hub and the ridgid. If I use SE cable I'll have to put a cable clamp in the coupling and I still have to bond to the ridgid riser. I can cut the ridgid but I can't make 3/4" taper threads that are required for feild cuts.
I'd appreciate any ideas you guys might have. Thanks
 

augie47

Moderator
Staff member
Location
Tennessee
May not be the most economical solution, but one often used here when folks can't thread is a rigid compression coupling at the meter.
 

malty

Member
Thanks for the reply. Can I get the rigid comp coupling in water tite? I'm using URD but I still wouldn't want any water leaks into the meter socket.
 

malty

Member
I found an old forum thread that I think answered my question. It was from 2007 titled compression fittings on rigid outside. From this thread I gathered that most standard rigid compression fittings are not listed raintight. There is a listed raintight that has an internal seal. I'll try to find one or see if I can find someone to thread the cut end.
 
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malty

Member
Most big box and large hardware stores can cut and threat 2" conduit.
I called the big box store HD and yes they can cut and thread the 2" rigid BUT it's a plumbing running thread.
(344-28 standard cutting die with a 3/4 taper per ft SHALL be used.) The guy at HD who I know is also a licensed electrician said my inspector passes it all trhe time. Still doesn't make it right.
 

tkb

Senior Member
Location
MA
I called the big box store HD and yes they can cut and thread the 2" rigid BUT it's a plumbing running thread.
(344-28 standard cutting die with a 3/4 taper per ft SHALL be used.) The guy at HD who I know is also a licensed electrician said my inspector passes it all trhe time. Still doesn't make it right.
Plumbing and Electrical threads are the same tapered thread, NPT.
You will need to protect the threads from corrosion. 300.6(A)
 
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malty

Member
Plumbing and Electrical threads are the same tapered thread, NPT.
You will need to protect the threads from corrosion. 300.6(A)
There is a FPN with 344-28
Plumbing pipe can be ether NPT or ISP
ISP running threads
NPT tapered threads
ISP is used mostly for black pipe. NPT most common for galv pipe.
I'll just make sure it's a NPT thread and protect cut threads from corrosion.
 

Cow

Senior Member
Location
Eastern Oregon
I've never seen anything other than NPT used for black pipe? I was sharing the same die our heating crew was using to run black pipe just the other day.
 

tkb

Senior Member
Location
MA
There is a FPN with 344-28
Plumbing pipe can be ether NPT or ISP
ISP running threads
NPT tapered threads
ISP is used mostly for black pipe. NPT most common for galv pipe.
I'll just make sure it's a NPT thread and protect cut threads from corrosion.
At HD, I am sure it's NTP.
 

malty

Member
Sorry I meant IPS pipe thread not ISP.
Google IPS pipe thread- IPS is the abbreviation for iron pipe straight thread.
Sorry about all the dumb questions but if all the types of threads were the same why would the NEC specify taper threads.
 

tkb

Senior Member
Location
MA
Sorry I meant IPS pipe thread not ISP.
Google IPS pipe thread- IPS is the abbreviation for iron pipe straight thread.
Sorry about all the dumb questions but if all the types of threads were the same why would the NEC specify taper threads.
Because there are straight and tapered threads.
NEC requires tapered.
 

renosteinke

Senior Member
Location
NE Arkansas
We're missing a few points here ....

First off, PoCo rules dictate where the service drop can be. Make sure they agree to the new location.

Next, PoCo rules typically forbid the use of ANY couplings in the service mast. If you need a mast longer than 10ft., you need to talk to them. A quick "cheat" might be to use unlisted non-conduit schedule 40 water pipe. Plumbers' pipe comes in 21-ft lengths, and is essentially identical to 2"RMC. (The only difference between the two ASTM specs is that the electrical conduit has a requirement ot be 'smooth' inside, while there is no such requirement for water pipe).

The PoCo will also have rules for support of the mast above the roof. Remember that you will have to maintain roof clearances.

Finally, the weatherhead typicall clamps to the pipe, so no threading is necessary.

Any plumber, hardware store, or home center ought to be able to thread a 2" pipe. I don't recommend the compression fittings for use on a service mast; you need all the strength you can get.
 

iwire

Moderator
Staff member
Location
Massachusetts
PoCo rules typically forbid the use of ANY couplings in the service mast.
You would have to check you local rules, here we can have as many couplings as we want. But the top stick must be a full ten footer. This means the cut has to be at the meter.


The PoCo will also have rules for support of the mast above the roof.
Here they severely limit how high above the structure we may have the mast pretty much eliminating the need for supports.


Remember that you will have to maintain roof clearances.
Keep in mind those will be NESC clearances not NEC.

Finally, the weatherhead typicall clamps to the pipe, so no threading is necessary.

Because they want a 10' on the top this does not help us.

Any plumber, hardware store, or home center ought to be able to thread a 2" pipe.
I know Home Depot will.

I don't recommend the compression fittings for use on a service mast; you need all the strength you can get.
I use compression connectors at the meter hub often with masts and all above that is threaded.

As you say, much depends on the local power company requirements and expectations.:cool:
 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
Remember that you will have to maintain roof clearances.

Don't forget clearances over yards, driveways, etc. Once you move the service attachment point, you aren't grandfathered anymore.
Clearances under NESC C2-2012 are still 12' over "spaces and ways subject to pedestrians or restricted traffic only", although the height may be reduced to 10.5' under certain circumstances. (normally we don't allow that). That height requirement is measured at the lowest point, or belly, in the wire, not the riser height.
 
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