Power line going to workshop is too low?

[Travis Conner]

I swear I can almost reach up and grab it stand ling by the meter so I want to say its 7ft tall. You aren't going to be driving any vehicles under it, that's for sure. I thought power lines were supposed to be atleast 12ft tall? Or is that only the line connected to the power poles?

[Jim Becker]

A photo would be helpful...

[Bruce King]

Generally 10ft, 12 ft over driveway and more in other cases.

[Bill Dufour]

I think it is 6 feet over a roof.
Bil lD

[Ron Selzer]

I swear I can almost reach up and grab it stand ling by the meter so I want to say its 7ft tall. You aren't going to be driving any vehicles under it, that's for sure. I thought power lines were supposed to be atleast 12ft tall? Or is that only the line connected to the power poles?

all depends on where it originates, what it crosses and where it stops.
Odds are all or most of the work/money to raise it is on you
ONLY if it originates on power company pole and crosses a public road, alley, etc is it possibly partially on the power company. It would have to be lower than 16-18 ft (depends on what it crosses) on the power pole and at least that height on your building where it is attached. THEN if it is too low for what it crosses the power company, inspector and you would have to have a meeting to determine who does what to get it higher. If the power pole in on your lot or adjunct to your lot and crosses no public space the height is a lot lower than crossing a public street.
"I swear I can almost reach up and grab it stand ling by the meter so I want to say its 7ft tall" THIS is on your nickle, attachment point is way too low on your structure.
Ron

[Charlie Velasquez]

From 2017 NEC. I don’t think many communities have adopted the 2020 cycle, yet.
Even then, local municipalities can choose to amend the NEC as they see fit.


230.24
A) Above Roofs. Conductors shall have a vertical clearance
of not less than 2.5 m (8 ft) above the roof surface. The vertical
clearance above the roof level shall be maintained for a
distance of not less than 900 mm (3 ft) in all directions from
the edge of the roof.

(B) Vertical Clearance for Overhead Service Conductors.
Overhead service conductors, where not in excess of 600 volts,
nominal, shall have the following minimum clearance from
final grade:
(1) 3.0 m (10 ft) — at the electrical service entrance to build‐
ings, also at the lowest point of the drip loop of the build‐
ing electrical entrance, and above areas or sidewalks
accessible only to pedestrians, measured from final grade
or other accessible surface only for overhead service
conductors supported on and cabled together with a
grounded bare messenger where the voltage does not
exceed 150 volts to ground
(2) 3.7 m (12 ft) — over residential property and driveways,
and those commercial areas not subject to truck traffic
where the voltage does not exceed 300 volts to ground
.....
(exceptions for over 300 volts nominal)


230.26 Point of Attachment. The point of attachment of the
overhead service conductors to a building or other structure
shall provide the minimum clearances as specified in 230.9 and
230.24. In no case shall this point of attachment be less than
3.0 m (10 ft) above finished grade.


edit: The NEC is now available online for free (requires you to register an email). Not searchable via keywords, nor can you highlight and copy, but if you’re familiar with its layout, you can eventually find what you’re looking for.
That link we have in the stickies has been dead for years. Maybe re-title it to point to the NFPA website?

[Alex Zeller]

I can't help with the code but I can offer this, for what it's worth. About 10 years ago we had a bad winter storm (yet was unusually warm) and a tree split. The part that broke took out the mast going to the meter on the side of his house. Of course the power company came out very quickly to cut power but when they showed up they told me that while they owned everything above the meter it was my father who had to pay for repairing it. His power line was also pretty low and he would use a long piece of wood to prop it up each time he would park his RV on that side of the house. Since he was paying to have an electrician come out we had him raise the mast up another 4'. You may want to call your power company and ask them. My father had no choice and had to pay "emergency" prices since going without power in the middle of winter isn't an option unless you have a wood stove in Vermont. But it may not be too expensive if it's a normal service call and you can get a few prices ahead of time.

[Jack Frederick]

My solution to most power supply issues is to bury it. Out of sight, out of mind & safe. The year we moved to our current house there were two storms which caused the big walnuts, 1-4’ & 2-30”, to shed a lot of their long horizon branches, pulling the service wiring out of the building. Twice in one winter is enough to motivate me. I carefully excavated around the roots and put it underground. Done!

[Charlie Velasquez]

My solution to most power supply issues is to bury it. Out of sight, out of mind & safe. The year we moved to our current house there were two storms which caused the big walnuts, 1-4’ & 2-30”, to shed a lot of their long horizon branches, pulling the service wiring out of the building. Twice in one winter is enough to motivate me. I carefully excavated around the roots and put it underground. Done!

Our power company will not do overheads anymore. In our community it was not the cardinals or goldfinches that signaled the coming of spring, it was the fleet of boring machines. Maybe the last 15 years??
I and the house next to me had already gone underground, but when the poco bored in our area they asked the rest of the residents to switch over also. Everyone said yes except for one elderly lady. Rather than fight a little ‘ol lady, they left a solitary pole up to feed her service.
Like vultures, they waited for her to die, and the city made it a condition of the sale of her property.

[Jim Becker]

Honestly, underground utilities really should be the goal almost everywhere because they are significantly more resilient to weather events. I don't get it why aerial remains so prevalent in areas constantly whacked by hurricanes, etc., but the poles and wires just keep getting replaced over and over and over. In those areas, that's gotta already be costing more than burying them once and for all. Around here, it's trees that largely cause disruptions.

[Alan Lightstone]

When I leave my community (which has buried power cables), the instant I leave the gates all of the power lines are overhead, usually tangled up with 100yo oak trees. In a hurricane, the chance that those cables go down is clearly 100%, which will wipe out the source of power to my community's buried cables.

I shake my head, and it worries me every time I look up, as hurricanes are certainly part of life down here in Florida. But no action whatsoever from Duke Energy to bury cables.

I remember when Hurricane Wilma cut power to millions of customers in South Florida for weeks to months. Only the city of Sunrise was unaffected (they had exclusively underground cables).

I passed literally hundreds and hundreds of power trucks from many states on the Florida turnpike coming down to help (the utilities helping each other get great credit for that).

It really is crazy to have overhead cables in this day and age, but I don't see much effort, at least around here, to put them underground.

[Jack Frederick]

We have a new acronym here. It is PSPS. Public Safety Power Shutdown. It is expected to be windy over the next few days, so they prepare us for power loss for the simple reason that PG&E’s system cannot safely operate in windy conditions. Truthfully though, in the foothills when a breeze comes up, you look over your shoulder.

[Tom Bender]

I think it is impractical to bury higher voltage lines so the big power will remain overhead.

[John K Jordan]

I think it is impractical to bury higher voltage lines so the big power will remain overhead.

We have a transformer on a concrete pad in the woods maybe 80' from the house. It is fed by a 7200v underground line. I understand the guy who built the house in 1988 paid to have it installed underground since is wife didn't want a 20' wide swath cut through the woods.

I'm glad it's underground. I've dug trenches and put every line I've added to the property (probably 1500') underground so we have no overhead wires. It's more work but all underground has probably eliminated several outages due to wind and trees.

JKJ

[Ron Selzer]

Have seen plenty of underground dug up for repairs. Takes awhile to find the problem, sometimes have seen the crew out for more than a month, was in early 2000's in a subdivision built in 70's. They have been in my subdivision a couple of times for repairs and adding extensions. Originally installed in the 90's. Don't lose power for very long, sometimes a large area.

[John K Jordan]

Have seen plenty of underground dug up for repairs. Takes awhile to find the problem, sometimes have seen the crew out for more than a month, was in early 2000's in a subdivision built in 70's. They have been in my subdivision a couple of times for repairs and adding extensions. Originally installed in the 90's. Don't lose power for very long, sometimes a large area.

My underground high voltage line blew out once. I was headed out to photograph a wedding when it failed and when I got back in a few hours they had made the repair and were filling in the trench.

441968

The utility had equipment that pinpointed the location. The problem actually was a pinpoint - I've got the short piece they cut out and spliced and the only thing visible is a tiny pinhole in the insulation.

JKJ

[Ben Helmich]

Honestly, underground utilities really should be the goal almost everywhere because they are significantly more resilient to weather events. I don't get it why aerial remains so prevalent in areas constantly whacked by hurricanes, etc., but the poles and wires just keep getting replaced over and over and over. In those areas, that's gotta already be costing more than burying them once and for all. Around here, it's trees that largely cause disruptions.

It’s waaaaay more expensive to do underground. This comes up in Houston after every hurricane. The good news is that the bad outages don’t happen very often. After Ike all the problem trees came down. It will take another 20 years or so for them to be a problem again. If two bad hurricanes hit close together, the second wouldn’t have the problem trees to blow over.

[Jim Becker]

Oh, I agree it's expensive to get the utilities underground. No question about that. At least relative to a short term decision. Longer term, especially with increasingly volatile weather patterns...the better play may be to suffer higher cost up-front to reduce cost (and outages) later. It's a balancing act.

[Travis Conner]

I think underground power is fine unless you live by the water. Everytime the water comes up on the land you can almost guarantee the power is going to go out. I guess it gets to those little transformer boxes sitting on the ground.

[Travis Conner]

Had an electrician look at it. He said it was fine since no traffic goes under it.

[Charlie Velasquez]

Had an electrician look at it. He said it was fine since no traffic goes under it.
Get the city inspector or Authority Havng Jurisdiction to check it, or take a pic with a length reference and take it in.

Just the fact that YOU can walk under it means that pedestrians can traverse under it. That and specs for attachment height for your masthead, including the drip loop means minimum of 10’.
I would not trust your electrician.

[John Stankus]

Honestly, underground utilities really should be the goal almost everywhere because they are significantly more resilient to weather events. I don't get it why aerial remains so prevalent in areas constantly whacked by hurricanes, etc., but the poles and wires just keep getting replaced over and over and over. In those areas, that's gotta already be costing more than burying them once and for all. Around here, it's trees that largely cause disruptions.

I can tell you exactly why. Cost. Back around 2003-2004 I was working in an advanced technology group at Nortel Networks. The ballpark was about $5 per foot aerial vs $100 per foot buried. This was for telecom infrastructure, power was probably a bit more.

At the time, I was the Nortel rep to one of the MIT Media labs industrial advisory boards and had quite the challenge of convincing them of the infrastructure cost to rewire (Install fiber) service to every home. The business models need to account for the real costs of the infrastructure. Some of this is why you see fiber installs going slow, and the innovation of shallowtrenching like google fiber is using. They did the shallow trenching in my neighborhood this summer. I can’t wait for the availability, since the copper plant is in such sad shape.

John

[Matt Day]

If it’s 7’ off the ground you’d be able to touch it, unless your less than 5’6”.

[Daniel O'Neill]

Seems like a good idea to go underground but it's really expensive. Additionally, all utilities on the pole have to go underground. Payback in our area is 33 years when resident pays a few thousand to switch their service. Air is an excellent at distributing heat away from the wires while dirt and pipes are not. Some larger duct banks actually have cooling. The companies definitely know the ROI both ways.


If humanity was good at long term thinking we'd have balanced budgets, but politicians & CEOs seem to think only about the next election and quarter. Not bashing not trying to be political just trying to surmise why a power company would not do something for their long term benefit. (put lines underground)

[Travis Conner]

I lived in a neighborhood with underground power, the power always went out just long enough to reset everything. Now I live in an area with what I believe is mostly overhead power lines and we don't have any of that bs. I don't see how underground power where lots of flooding occurs is a good idea.

[Jim Becker]

It's mostly about wind, Travis. Wind is the primary issue in the south and you add ice to that in the northern climates. I agree that underground has its own issues with things like flooding, but that "should" be accounted for in how it's installed. But we all know that best intentions are not always honored in that respect.

[Daniel O'Neill]

Sounds like the wire was going bad. Underground is subjected to a lot more moisture (water) in the conduit and will cause faults all over the place. If the wire is in conduit that is. Some of the old guys like to direct bury which allows for the splice Jordan had above but then the only way to fix a truly bad wire is to re-trench. 6 of one 1/2 dozen of the other. In a world where labor is usually the biggest cost, making it easy for the linemen to pull new wire fast via conduit is likely the way to go in most situations. Plus less yard/tree damage. Overhead has a lot of maintenance costs people don't see but certainly not conduit full of water :) Inside the transformers & vaults there is a gravel pit to try and dissipate that water and original civil engineering should mitigate 100 yr flood elevations so I'd say in most of the country you should be good. Additionally, underground wire is rated for wet locations. Also, wind as Jim mentioned & trees & birds & squirrels... and Kites that get loose. (We had to hire a helicopter to clear a 138kV line)



I lived in a neighborhood with underground power, the power always went out just long enough to reset everything. Now I live in an area with what I believe is mostly overhead power lines and we don't have any of that bs. I don't see how underground power where lots of flooding occurs is a good idea.

[John K Jordan]

Electricians have mentioned every underground conduit somehow gets full of water, no matter how well the conduit joints are sealed. Apparently water hurts nothing. The conduit is for protecting the insulation from physical damage.

[Travis Conner]

I live by the water now Jim and everytime we have a hurricane and the water comes up 4ft or so I can guarantee the power will go out. I'm not sure if the transformer (green boxes) are going under water or what, but they usually have it back on in 2 or 3 hours. I do believe their is a 240/120 transformer box right next to the bulkhead in my neighborhood so that means it's about 4ft above the canal. lol

[Frank Pratt]

Electricians have mentioned every underground conduit somehow gets full of water, no matter how well the conduit joints are sealed. Apparently water hurts nothing. The conduit is for protecting the insulation from physical damage.

That's what this electrician says too. The wire that's pulled in there is made for wet locations & in a hundred years will show no ill effects, as long as the insulation hasn't been damaged.

We had a 400A underground service feeder fail after just 3 years. It was 4 conductors of 750 MCM RW90 aluminum in concrete encased 4" PVC conduit. It's pretty big stuff; the wires are about 7/8" in diameter. What happened is that the guy drilling post holes for a garbage enclosure thought he's go ahead to do it without getting locates done. Then when the auger hit the concrete, he just kept pounding away at it until the tip of the auger went through the concrete, conduit, and pierced 2 of the phase conductors.

The conduit was full of water & 3 years later it did its job & the power went out. One of the conductors still had continuity, but was badly swollen & on its way out. The other had the insulation burst wide open & the aluminum strands had all turned to white powder. It was an expensive repair, with the feeder being 100M long and the restaurant was closed over a week because of it.

I saved that chunk of wire & keep it on my wall of shame in my office.

[Charlie Velasquez]

Electricians have mentioned every underground conduit somehow gets full of water, no matter how well the conduit joints are sealed. Apparently water hurts nothing. The conduit is for protecting the insulation from physical damage.

Any underground is a wet location. The water does not come from the soil or joints, but from the air.
The temp, 18”, 24” whatever below grade is different than above ground. Unless the conduit and the termination points of the conduit are exactly the same temperature, you have a convection current. May not be strong, but it is constant. The air is always changing.
Anytime that subterranean conduit temp is lower than the dew point of the above ground air, the water vapor condenses.

A hot humid day, you get a few drops of condensation. A few here, a couple there... after a few weeks, you have a wet location.

[Daniel O'Neill]

Travis that's correct the enclosures are not waterproof the wire is. So it's likely that the water is connecting terminations that should not be connected.


I live by the water now Jim and everytime we have a hurricane and the water comes up 4ft or so I can guarantee the power will go out. I'm not sure if the transformer (green boxes) are going under water or what, but they usually have it back on in 2 or 3 hours. I do believe their is a 240/120 transformer box right next to the bulkhead in my neighborhood so that means it's about 4ft above the canal. lol

[Daniel O'Neill]

Frank,
We have had those too. We avoid pulling wire, if possible, in late winter when the pipes are likely to have significant ice in them. Gotta call the locates glad nobody got hurt. We require open trench near primaries but that only helps when they call the locates in or ask about a utility atlas for their dig location.
Daniel

[Travis Conner]

There's no sunlight underground to dry things out underground. I guess if you only have a short run where you can run it without having a connection underground then it would stay dry, but my guess is they bend the pipe then install a straight pipe after that, so there goes your seemless connection.

[Frank Pratt]

There's no sunlight underground to dry things out underground. I guess if you only have a short run where you can run it without having a connection underground then it would stay dry, but my guess is they bend the pipe then install a straight pipe after that, so there goes your seemless connection.

Even if you had perfectly water tight joints in the pipe, it would still get wet from condensation in the pipe from warm, humid topside air migrating into the conduit.

[John K Jordan]

.... 4 conductors of 750 MCM RW90 aluminum in concrete encased 4" PVC conduit. ...

I've given up on aluminum wire. I had a 4-conducctor direct burial aluminum feed fail after a number of years - no digging or external disruption of the insulation. One conductor went first, the others followed over a few weeks. Best we could figure was a rock or two worked into the insulation over the years or the insulation came damaged or was nicked during installation. Aluminum corrodes to powder. I didn't bother to dig it up but dug another parallel trench. I don't care if aluminum is way cheaper, for me it's copper in conduit from now on. I even run direct burial copper cable in conduit to help protect it from wayward shovels and such.

JKJ

[Frank Pratt]

I've given up on aluminum wire. I had a 4-conducctor direct burial aluminum feed fail after a number of years - no digging or external disruption of the insulation. One conductor went first, the others followed over a few weeks. Best we could figure was a rock or two worked into the insulation over the years or the insulation came damaged or was nicked during installation. Aluminum corrodes to powder. I didn't bother to dig it up but dug another parallel trench. I don't care if aluminum is way cheaper, for me it's copper in conduit from now on. I even run direct burial copper cable in conduit to help protect it from wayward shovels and such.

JKJ

The cost difference is just to great to write off aluminum, especially with larger feeders. Aluminum simply will not fail if installed correctly. Direct bury cable needs to be properly bedded if not in conduit. If you do get a fail in direct buried cable, it's not a huge deal to splice it in situ. A locator can pinpoint the location very closely. Hand dig it up, or hydro-vac it to expose the cable.

I've done several dozen underground splices back in the day when they'd just let you throw it in the ground & back fill it. Now code requires the conduit or sand bedding. Personally, I always go for the conduit and bedding as well if it's at all rocky.

[John K Jordan]

The cost difference is just to great to write off aluminum, especially with larger feeders. Aluminum simply will not fail if installed correctly. Direct bury cable needs to be properly bedded if not in conduit. If you do get a fail in direct buried cable, it's not a huge deal to splice it in situ. A locator can pinpoint the location very closely. Hand dig it up, or hydro-vac it to expose the cable.

I've done several dozen underground splices back in the day when they'd just let you throw it in the ground & back fill it. Now code requires the conduit or sand bedding. Personally, I always go for the conduit and bedding as well if it's at all rocky.

My ground was topsoil and red clay, very few rocks. I bedded the cable in sand. A locator showed the first conductor failed first in one place then a few days later in a second and possibly a third place. Very odd. (I could watch the voltage decrease by the hour.) A few days later the second conductor failed. For a while I ran power on the smaller common and ground to the panel, enough to keep the electric gate powered (The gate was another 450' underground, copper in conduit already). Then the third conductor failed. That multiple conductors failed confused all the experts I consulted. The best guess was I was sold some bad cable.

I gave up and dug a new trench and laid copper in conduit, over sized for 80+ amps, far more power than I needed. I didn't care what it cost - I just didn't want it to fail again. The remote panel is at the site of a future equipment building.

Since I had the equipment and the time the only cost was the wire, conduit, and the diesel fuel.

444087 444088 444089

The run to the first panel box was almost 700'. For temporarily power while laying the new line I ran 100's of feet of extension cord to keep the security gate batteries charged. The aluminum is still in the ground if anyone wants to pull it up. Probably worth something for scrap.

JKJ

[Frank Pratt]

I can understand why you just replaced the whole run. When you have that many points of failure happen like that, it's best to just cut your losses.

[Travis Conner]

All they need to do is tighten the cable and it can be raised up another 2ft or so.

[Jim Becker]

All they need to do is tighten the cable and it can be raised up another 2ft or so.

I had that issue awhile ago here for our home...it took me nearly two years to be able to get the power company to tighten up the cable and the final straw was a tree limb falling and ripping it loose, all this despite the fact that the cable actually crossed the busy state road to get to the pole and that the length of the line is long enough that I could nearly touch it at the halfway point. Be persistent....

[Travis Conner]

I wonder how often the wire gets damaged from being run through the conduit. Like if you don't have a helper to feed it through while you pull. I pulled out some thhn wire that had the outer plastic jacket torn one time. Nothing wrong with it, but still.

[John K Jordan]

I wonder how often the wire gets damaged from being run through the conduit. Like if you don't have a helper to feed it through while you pull. I pulled out some thhn wire that had the outer plastic jacket torn one time. Nothing wrong with it, but still.

I put heavy wire through conduit a different way. I lay the wire bundle in or beside the trench then feed the conduit one length at a time down the wire and glue it to the last one. Then I fill in the trench. This requires a lot of walking for a long run but I think it is a lot simpler than pulling large conductors. Can't damages insulation. So far I've installed about 1500' in three runs this way here at the farm.

[Charlie Velasquez]

I put heavy wire through conduit a different way. I lay the wire bundle in or beside the trench then feed the conduit one length at a time down the wire and glue it to the last one. Then I fill in the trench. This requires a lot of walking for a long run but I think it is a lot simpler than pulling large conductors. Can't damages insulation. So far I've installed about 1500' in three runs this way here at the farm.

NEC frowns on this.
The pvc conduit and the polyvinyl insulation are close enough that the cement can compromise the insulation. Even fumes, according to people on the Mike Holt forum.

The interior of the bells are beveled, any cuts should be field beveled. Bells should go in the direction of the pull. The head of the pull should be tapered and taped, starting from the conductors and taped toward the head, or use a pulling sock. Offset the conductors, and on 6awg and smaller consider offsetting, stripping some insulation, and bending back before taping to the body of the conductors making a rounded head on each conductor. Keep the conductors kink-free. Keep dirt out of the conduit, add pulling conduit bodies on long runs... and lube... lots and lots of lube.

[John K Jordan]

NEC frowns on this.
The pvc conduit and the polyvinyl insulation are close enough that the cement can compromise the insulation. Even fumes, according to people on the Mike Holt forum.

The interior of the bells are beveled, any cuts should be field beveled. Bells should go in the direction of the pull. The head of the pull should be tapered and taped, starting from the conductors and taped toward the head, or use a pulling sock. Offset the conductors, and on 6awg and smaller consider offsetting, stripping some insulation, and bending back before taping to the body of the conductors making a rounded head on each conductor. Keep the conductors kink-free. Keep dirt out of the conduit, add pulling conduit bodies on long runs... and lube... lots and lots of lube.

Thanks. I wondered if the glue would soften the insulation so I globbed some on as a test. I couldn't detect any affect. Maybe it depends on the cable, maker, different formulations of insulation, the temperature, the phase of the moon, who knows. I just tried it on the power conductors, not the green insulation on the ground wire.

JKJ