Trenching for Underground Electric
Our farm is at the end of the line for both phone and electric. For years I have wanted to move the utility pole that is across from our driveway because it is in the way of trucks turning and unloading hay. Upgrading the electric for our big project was the time to do it. To install underground electric back to the previous pole required digging approximately 300 feet of trench on a steep bank by the road. It felt like the tractor was almost vertical although in reality it was only about a 45° angle. I was just barely able to get up the bank with our little tractor and then dig out the required trench to spec. It must have been quite the sight for drivers going by seeing the tractor looking like it was going to plunge nose down into the road.
Swinging on a Slope
In high school I competed on the uneven parallel bars. Swinging back and forth between the backhoe and tractor seat reminded me of that. Loads of fun! No, I did not do a dismount to the ground from up there – just landed in the seat nice and neat.
There were three stumps that were too large for the tractor to get out, especially at the disadvantage of that angle. Two of them I cut through with a chainsaw – very bad for the blades which is why I used old chains. Fortunately Will is quite good at sharpening them. The third stump we dug under and ran the conduit beneath it. Fortunately there was only one boulder of significant size, other than the ledge of the mountain that is. The ledge stops all penetration since I didn’t want to blast and didn’t have the time to fire crack it.
Once the trench was ready on both ends I dug across the driveway, isolating us from the world for a few hours. We left the van parked on the road side of the cut while I had the trench open.
At about 8 pm that night we ended up actually placing and gluing the conduit. It was so late because we wanted to close the driveway section of the trench up before whey came in the morning. The newspaper that Hope is placing is to help keep the ends of the conduit clean so we can get a better glue joint. Each end then gets wiped clean, washed with alcohol and primed before being solvent glued together. Working with the conduit is much like doing waste water plumbing. We sped up the process by assembly lining it such that each person did a piece of the job leap frogging ahead as the pipe was joined such that we did it in about a minute per joint. That’s fast.
We used 3″ diameter PVC Schedule 40 conduit. The wire is about 2″ in diameter giving about half an inch extra on either side as it slides through the pipe. The wire would have just barely fit in 2″ diameter conduit but then it would have been tight and could have easily bound up. Pushing the wire through the 3″ conduit made me really appreciate that extra width.
Wire Reel on Tractor Forks
Holding up a wire reel is another good use for forks. Spinning the wire off the reel held up by the tractor forks we found we could push the wire about 180′ into the conduit. Then we needed to be both pushing and pulling after that to get 350 MCM URD three wire set to go the last the last sixty feet. A pull wire would have helped even more.
Pedestal Trench Open
This is the pedestal that Walter built, ever so straight and level… Holly said it looked professionally done. Gee whiz, blush… :) In the photo above the long sweep elbow is coming up under the box. It is very important to get the conduit level and right so that the expansion joints can operate smoothly with frost heaving. I saw one in Lebanon, NH where it had not come out right and the conduit broke. I’m striving to avoid that problem. Hopefully I have learned someone else’s lesson and gotten it right here.
There is a second pipe in the trench. It is a 4″ extra conduit of drain pipe just incase we someday want to lay another wire. I don’t want to be digging up the dirt and disturbing our electric line so this is cheap planning for possible futures. Trenching is hard. Pipe is cheap.
To prevent accidental digging up of the electric line we put scraps of pink foam insulation on top of the conduit after the initial layer of dirt. This will give warning to anyone digging. Once I thought our water line was a little further over than it was and hitting the pink foam warned me to stop digging. A good use for scraps and cheap protection from disaster. It also stops the frost along the driveway section which will be exposed to the deep cold of winter. Above that went more dirt and then the “No Dig” red tape before the final layer of soil.
We get a lot of lightning. In fact, this past Friday we had a mega-doozy of a thunder storm with hits that were just barely up hill of the cottage as well as throughout the valley. Good grounding and frequent grounding helps to reduce the damage from lightning surges. I also installed a $50 “Leviton Meter Socket Surge Arrestor 50240-FAA” which installs behind the meter on the pedestal. I have not previously had a whole house surge suppressor, instead relying on Panamax outlet surge suppressors which have done well for us. Now we have both and I hope are that much more protected. The Panamaxes I use in series and I know they work because it is not uncommon for the first in the series to get blown out once or twice a year. Cheap insurance for expensive equipment further up the line in the bubbles of protection.
The pedestal also has a shut off so that I can turn off power there making it safer to work on the sub-panels. This is something I’ve always wanted as I’m not terribly fond of reaching into our existing breaker box where there are always some live wires. The meter / breaker box I ended up getting was the “ TSM420CSCU “200A Outdoor Meter Socket Main Breaker Load Center” which the Washington Electric Coop field technician said was a good one when he saw it here. Good to know.
Tractor Filling Trench – Sort of…
I was able to dig the trench for the conduit but filling it back in was too dangerous – I reared the tractor back up on it’s rear wheels several times before giving up. In the photo above I’m making the grade but in most cases I could not quite get there. For a while we shoveled dirt by hand but then Holly came up with a better solution. I placed the dirt along the edge and call for bigger equipment.
Skidder Filling Trench
Zack, one of the loggers who is working on our field cuttting, brought a skidder over and pushed the dirt up the last bit of hill into the trench. Where the tractor had whined and struggled the skidder easily did the job in about 15 minutes. That skidder is bigger than our tiny cottage…
Washington Electric Crew
Tuesday morning the WEC crew showed up bright and early at our place. Also that day the loggers were skidding, cutting and lopping just across the road at our east field landing, the town was putting in a new culvert, whey got delivered and the highway that loops around the mountain was getting road work so we had extra traffic. All this was going on while we continued work on clearing the slab site for our first pour of our big project. An exciting and busy day at the end of our driveway.
To move the power the electric company people needed to set an new anchor for the next pole back. In Vermont, if you dig, you hit rock or ledge very quickly in most places. Our land is no exception. In fact, it is more like the rule. And of course, right where they needed to put the anchor there was granite ledge one foot down. Fortunately they know Vermont and came prepared with a major compressor driven hammer drill. I stood by and drooled. My tool is much smaller.
While they set the anchor and moved the transformer Holly and I ran some errands in town, including picking up a circuit breaker. There are two types, Square-D, which I’ve used for years, and the other kind by Murray and such which fits in the new circuit breaker box. I had the wrong one. Going into town’s a long trip but it is done. Fortunately we were able to combine it with other errands. By the time we got back the crew was removing the extra pole at the end of the line which used to have our transformer. The new transformer was already installed on the next pole back and set to go. In the photo above the pole man is getting ready to set the harness to lift the pole up out of the ground.
They used the combination auger / bucket / lift boom to pull the pole up out of the ground, very, very slowly. I had wondered if they would just cut it off, not knowing how deep it was or how hard it would be to pull. The gentleman in the orange shirt on the back of the truck at the controls then set the pole down by the road neat as can be. With a flip of the switch we were once more empowered.
New View of East Field – Click for Big View
The above panorama shows starting at the left the new transformer on the next pole back with the new anchor line and our underground electric, Lili dog pretending to be a rock on the side of Riddle Pond Road, the view across the valley through the new east field, the logging landing to the right with mists over the marshes, Riddle Pond Road again (this is a fish eye view of a straight section of road), the old pulled pole lying by the road and then our farm gate.
Start to finish the new power took about four weeks. Much of that was waiting for the rains to dry. Work was in quick spurts between the rains and other projects. Once we were ready the Washington Electric Cooperative crew were in and out, quickly and efficiently doing their job of switching us over from the arial to the underground wiring. 200 Amps of 240 volt service. Hopefully we’ll never need that much power but now it is there and ready incase big projects require big power.
Outdoors: 75°F/42°F Partially Sunny
Tiny Cottage: 78°F/70°F