Underground Utility Installation
So today’s all about underground utilities. We’ve been installing many of them on our home remodeling project in Middleton, Idaho. Right behind me, you can see a new 400-amp underground service. I’ll walk you around the project and show you our progress. We’ve been here about a week and a half, so a lot has been done.
Ancient 60-amp Overhead Service
What you’re looking at here is a 60 amp overhead service. It’s ancient; I don’t know how long it’s been here. It’s on the pole, with a rope holding it up at the top, which is super dangerous.
This pole is being removed as part of the new underground services. Down below, another pole in a pasture is getting removed. The pole down at the street with a transformer will move about 10 feet to the south side.
New Underground Service Installation
So, on my left, an enormous pole with a larger transformer will serve this underground. We’ve dug a trench that I’ll walk you down there soon. You can see how the conduits are laid out. This trench extends from the road down to where we have a J box. We dug about 160 feet and then installed a 17 by 30 J box underground.
Conduit and Panel Installation
This three-inch line runs back up to the trench and connects to the panel on the shop’s side. Conduits for low-voltage, water-line, and high-voltage lines also go to the gate.
Behind me, all the panels are tied together. The electrical panel, low voltage, and all that — the boxes are right here behind me. This is a 200-amp disconnect on the left.
Meter Base and Disconnect Details
The centerpiece is a 400-amp meter base. Another 200-amp disconnect is on the right. These disconnects serve a house, barn, or shop requiring 200 amps. This one’s for a future barn, with a 200-amp electrical setup and breaker areas. The other side feeds the house. We have a three-inch conduit with a three-inch radius sweep running to the street.
They will pull the wire from the power pole to the J box. You can see how it looks from the side, coming up to the 400-meter base center. Then it sweeps into the ground. We need at least 30 inches of cover over that pipe. As the code requires, anything above ground must be scheduled 80 for sun exposure.
Expansion Coupler and Low Voltage Line
You also have an expansion coupler. If the ground freezes or heats up, the expansion coupler moves, preventing pipe damage or disconnection. We still need to connect one low-voltage line. You can see here the expansion coupler can slide up or down if there’s expansion or ground movement, preventing breakage or detachment.
Main Sub Feed and Future Barn Setup
This is a 200 disconnect, with a two-inch conduit as the main sub-feed to the house. It sweeps down with a 24-inch radius, schedule 40, because it’s below grade. It runs down the ditch, turns at a 90 lead, and heads to the house. Another two-inch conduit comes out of the other disconnect for the future barn. We stubbed it out and taped the end for future connection.
Low Voltage and Water Lines
You see two one-inch lines here, schedule 40 for low voltage cable and phone to a future barn. The water line is also present. We’ll extend the trench and tie in utilities when the barn is built. We installed a frost-free hydrant for year-round water without freezing. Pea gravel at the bottom allows drainage when the hydrant handle is closed.
Drain and Gate Power Setup
This is a drain for a future irrigation valve. For driveway power, we ran a one-inch conduit to the gate for a gate operator. We added a circuit for horse water heaters with a breaker in the panel. For low voltage, we used a can with no holes. Feeds from the pedestal at the street come in and sweep back out.
Hub for Phone and Cable Distribution
We have a hub for phone, cable, and everything from the street, and we distribute from there. Six conduits tie in here, with an additional one for a camera at the gate. Let’s walk down the ditch and see how it’s all laid out to meet code. Separation between low-voltage, high-voltage, and water lines is maintained.
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Conduit Layout in the Ditch
Now, we’re walking down the ditch, seeing where all the conduits tie in at the shop. This is a combination of high-voltage, low-voltage, and water lines. The three-inch main service pipe is on the right. We need a 12-inch separation between low-voltage lines and the main service. This trench is three feet wide, with a specific layout for each type of line.
High-voltage and low-voltage lines can cross perpendicularly. This high-voltage two-inch line is crossed by the low-voltage above. We pack dirt under pipes to prevent settling during backfill. The irrigation line has a compression coupler for repairs. This three-inch main service is on the left, low-voltage in the center, high-voltage, and water line on the right.
J Box and Power Company Setup
A 17 by 30 J box will be installed here, with a 28-inch spread between conduits for wire folding. The power company stakes and holds these conduits in place. The sweep heads back to the road. Along with the main line, we have three low-voltage lines: one for the gate operator, one for the phone, and one for the cable.
Future-Proofing Low Voltage Lines
There’s only a phone line, but we’re running extras for future use. This high voltage line will power horse water heaters and the gate operator. Sweeps come up for service, and water lines are in place. We installed frost-free hydrants with pea gravel for drainage, preventing rusting below grade. Workers are installing another hydrant and high-voltage line for a horse trough.
Gate Operator and Loop Sensor
This low-voltage line runs to the gate for a loop sensor, triggering the gate to open. Separation is maintained between the main service, low-voltage, high-voltage, and water lines. This run is about 160 feet. We did all the digging with a mini excavator. We capped the line for future tie-ins.
We have a low voltage for the gate and a high voltage for the gate operator and camera. Another frost-free hydrant is installed. We swept up for phone access at the pedestal and left an extra line for the new pole. The vacuum truck blew out a hole, leaving flexibility for the pipe. Idaho Power requires this setup.
Conclusion
I hope you enjoyed this update on our underground work. Check out our resources or request a project consultation with us for more information.
