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FrankC
May 7, 2007, 05:09 AM
I am putting a small addition on my house and have to move the service entrance underground conduit and meter base from one wall, around an outside corner to an adjacent wall. The meter base is about 2 feet from the corner of the two walls and I am hoping to dig down to the 3" schedule 40 conduit for a horizontal length of perhaps 15 to 20 feet, "bend" the conduit up and move it over to the other wall and drop it back down. It will end up about 3' from the same corner but on adjacent wall. I will not move the interior breaker box. 200 Amp. Uses SER, 2 ea 4/0 & 1 ea 2/0 AL. (I am assuming the service entry cable is in conduit all the way to the pad mounted transformer).

I am hoping not to cut the schedule 40 and not even disconnect the conduit from the meter base. (The power company will shut power off during this maneuver). I don't know how much horizontal distance it will take to uncover the conduit enough to "bend" it enough to make the change.

Question is: can I use individual XHHW-2 conductors inside rather than the SER cable between the meter base and breaker box? I have to reroute the cable inside and have to turn a corner through 2x6's. I don't know whether I can form the SER cable around the corner. I would have a much better chance forming the conductors one at a time through the studs. I would use nail plates for protection. I plan to sheetrock over the two adjacent walls...

I don't understand the difference between SEU and SER. And since the total length of the cabling will be perhaps 10 feet, would it make sense to use 3 ea 2/0 copper conductors instead of the aluminum wire? --- perhaps I could purchase 30 foot of copper conductor more easily than 10' of aluminum 2 conductor and ground SER/SEU cable.

Thanks for the advice!

Frank

tkrussell
May 7, 2007, 04:37 PM
SEU is three wire cable, SER is 4 wire cable, with an equipment ground. 4 wire is used from a disconnect, such as a breaker at the meter, to the panel.

Sounds like your proposing to run open conductors without conduit or any raceway. Can't do that.

You say there is already SER cable, will need to stay with that. Best to run a new longer piece instead of splicing. Large wires need large splices, best left to a pros to make good solid splices, esp with aluminum wire. Actually cheaper to run new wire than spend on the splices,tape and junction box.

FrankC
May 7, 2007, 08:12 PM
SEU is three wire cable, SER is 4 wire cable, with an equipment ground. 4 wire is used from a disconnect, such as a breaker at the meter, to the panel.

Sounds like your proposing to run open conductors without conduit or any raceway. Can't do that.

You say there is already SER cable, will need to stay with that. Best to run a new longer piece instead of splicing. Large wires need large splices, best left to a pros to make good solid splices, esp with aluminum wire. Actually cheaper to run new wire than spend on the splices,tape and junction box.
Thank you for the reply. Yes, I was hoping to use individual conductors because it would be easier to make the 90 degree turn through the corner of the room. That SER stuff is extremely stiff as you know. This particular cable is three conductor... two 4/0 and one 2/0. But nevertheless, I'll have to figure out how to get it through the corner. If you have any hints to do that, I would appreciate your sharing those. The walls are 2x6, and luckily, there are no hidden studs... meaning that the cable will be visible as it makes the corner.

Another big problem I will have to face is that I will have to cut the 3" sch. 40 conduit in the ground -- it is down around 30". And I will have to do that with the cable still inside (with the power off). Then I plan to slide the cutoff portion (mainly a 48" sweep) off the end of the wire and slide a coupling and a 45 degree elbow on and then slide the sweep back on. Any suggestions on how to cut the conduit without nicking the cable inside?

Thanks for advice!

Frank

tkrussell
May 8, 2007, 06:25 AM
Be careful not to remove too much wood from the framing member the cabe will pass through. The outer edge of the cable should not be closer than 1-1/4" away from either edge of the wood. Even if you can achieve this, you may want to protect it with nail plates.

Yes SER cable is very difficult to work with, esp in tight corners. Now you get a feel of how hard this work can be electricians do every day.

As far as cutting the PVC with wires inside, use a campers saw. This is a rough steel cable/wireabout two foot long with two finger rings you pull back and forth on a round object to cut through. Campers use it to cut wood limbs. These work slick to do this task. Need to keep cutting and moving the cable all around the perimeter of the conduit, watching not to cut through the last fraction of an inch of conduit wall. Once you get to just a nibble of PVC before you get to the wire stop cutting and snap off the conduit.

FrankC
May 8, 2007, 07:56 AM
Thanks again for the excellent advice and tips. The studs are 2x6's, so I can bore a 2" hole through their centers and be OK. I did buy nail plates for each stud just to be safe -- not that that does much for the outside. And I will buy one of those saws, that you were so kind to provide an ordering reference for, to cut through.

Still too wet here to dig down far enough to see the conduit.

Someone has offered to give some overhead type wire to me to run inside between meter base and breaker box. However it is actually separate conductors with no common sheathe. I suppose there is no way to tape around them or "something" to make that useable (?).

Again thanks for your support.

Frank

tkrussell
May 8, 2007, 03:02 PM
Yes, on the 2" hole, if plumbers can do it so can we. Seriously, I will say thou if this is a supporting corner, may be best to beef the structure up as much as possible. Depending on the amount of building on top of the corner, may need to reinforce with steel plate or column, just to be safe.

Using the cable in conduit is tacky, never done in the trade, but technically there is no stopping anyone.If the main breaker is inside in the panel, then 3 wire is needed. If the main breaker is out at the meter, then 4 wires are needed to the panel. There is nothing else that will protect the wires except conduit.

Your welcome.