500KVA within 80' of new home contruction and everything metal is energized

[harley13]

we are currently wiring a new home within 80' of 500KVA overhead power lines. yesterday I measured 709volts forn the 4'*8' sheets of aluminum sublayer below the deckng. everything metal is energized within the home. another contractor touched his piperack on his truck while standing on the driveway and received a shock. The a/c ducting system, steel bath tubs, fire place insert, dryer vent has voltage to it. GA. Power told me to bond everything and it should be ok?? what about the homeowner installing a swingset or metal fence along the property line or even the dish t.v. on the roof? Are there any precautions i need to take as i bond everything anyone with this experience i need some help. Is this safe for people to move into?

 

[junkhound]

precautions i need to take as i bond everything (think you meant 500kV, not 500 kVA?)

Kind of tongue in cheek, but do not put any light bulbs in series with your grounds, or GA pwr will try to bill you!

EE friend had a house next to a 345 kV line, hip roof house. Had aluminum gutters, he made them into a big loop with a single open gap and built a one-of-a -kind inverter to tap into the 'free' power. Said he got almost a hundred watts out of it, but never saw the raw data.

Have read of farmers putting a couple of poles in their field under high kV lines with a huge pickup coils, poco sued to have then torn down.

25m (80 ft) from 500 kV , electric field strength is about 200 V/m.

 

[JoeTroubleShoot]

Bonding everything will help, but maybe not a lot. Depends on how good your ground rods will work for you and even if you have good earth, it may still be annoying to live there. Opening a car door will give you a little shock and anything metal that has a little bit of mass that is not bonded will get a shock. It will be safe to live there, but it might be annoying. You're probably not really reading 700volts or so, you need to add resistance to your meter to get a real reading.

When we work an dead transmission lines that run parallel with live transmission lines, we heavily ground the dead circuit and still get pretty good shocks from induction when working.

A long metal fence will be very well grounded, but will still pick up induction. 345kv and up do a good job of inducing voltage no matter how well everything else is grounded. Induction is really the most dangerous on dead transmission lines that run parallel with live lines, other than that for the most part, it's just bothersome, but not dangerous.

 

[GoldDigger]

A reading of 700 volts with a high impedance meter is a perfectly real voltage in terms of breaking down insulation, including skin, and arcing across small air gaps.
It just has a high effective source impedance and so cannot sustain a high current.

Sent from my XT1080 using Tapatalk

 

[JoeTroubleShoot]

A reading of 700 volts with a high impedance meter is a perfectly real voltage in terms of breaking down insulation, including skin, and arcing across small air gaps.
It just has a high effective source impedance and so cannot sustain a high current.

Sent from my XT1080 using Tapatalk

I stand corrected, yet again...

 

[meternerd]

Having worked within high voltage substations for many years, I have found that grounding of metal parts does not insure that you won't get shocked...in fact, it's just the opposite. When you are within the inductive field of high voltage transmission, it actually can "charge" your body up to a voltage that discharges to ground when you touch a grounded metal structure. That's why it's necessary to "bond on" to ground with a wrist strap or some other means while working around grounded equipment. That way, you only get zapped when you first ground yourself. Beats getting buzzed every time you accidentally touch ground. I'm not saying that's what's happening here, but it does happen, especially with higher voltages such as 345KV or 500KV AC. 500KV DC won't do it.

 

[Fulthrotl]

we are currently wiring a new home within 80' of 500KVA overhead power lines. yesterday I measured 709volts forn the 4'*8' sheets of aluminum sublayer below the deckng. everything metal is energized within the home. another contractor touched his piperack on his truck while standing on the driveway and received a shock. The a/c ducting system, steel bath tubs, fire place insert, dryer vent has voltage to it. GA. Power told me to bond everything and it should be ok?? what about the homeowner installing a swingset or metal fence along the property line or even the dish t.v. on the roof? Are there any precautions i need to take as i bond everything anyone with this experience i need some help. Is this safe for people to move into?

i've worked in switchracks above 230kv bus, and on warm afternoons, you could lay a 10' piece of GRC parallel
to the bus, and clip on wires, adjust the spacing to get the voltage you wanted, and run a 120 volt drill off it.
you also had to wear leather gloves when opening the truck door, or you'd get zapped pretty badly... rubber tired
truck, more better grounded sparky.....

first off, living under that isn't healthy, but that's a separate issue.

if i had to make a residence in that situation, i'd run everything in EMT,
put 4 ground rods at each corner of the house, cadweld a #6 to them
to ground the house, and under the stucco i'd but expanded mesh,
bonding it to the ground loop around the house every 6' or so.

i'd essentially make a faraday cage out of the house.

for phone, internet, etc. i'd use something like verizon fios, and do everything
with that.

i'd pipe the house in copper, not pex, and bond that to the cage everywhere i
could.....

there is also flooring, that is an electrical semiconductive property, used in
chip fabs and the electronics industry, where static, and transient voltage is
a concern.

and of course, when the kids are playing in the back yard, you may want
to consider faraday suits, like the helicopter wiremen use when riding
the HV distribution cables......

geez.... i'd buid somewhere else....

 

[arits74]

why would anyone in their right mind want to live in such a place.not just the chance of getting shocked but it cant be good health wise.

 

[ggunn]

The resident should not try to build a recording studio in that building.

 

[JoeTroubleShoot]

why would anyone in their right mind want to live in such a place.not just the chance of getting shocked but it cant be good health wise.

It actually has some benefits... sometimes the utility doesn't care if you extend your yard into the right of way as long as you don't build structures and prices are a little cheaper. In some towns the only place where you can get a big back yard is next to a right of way. Lineman don't have a higher rate of cancer than any other type of profession so I can't see how living near transmission lines can be harmful.

Whenever working with a guy that has never been on transmission, it's always fun to grab something grounded and touch them on the nose. Like meter nerd said, everything else is grounded and you hold a charge when working out of an insulated bucket so a nice slow touch on the nose will put a nice scare into someone.

Definitely need to put more thought into what building materials before hand like what was mentioned before. There's things to do to help it, but you can't stop it completely.

 

[kwired]

why would anyone in their right mind want to live in such a place.not just the chance of getting shocked but it cant be good health wise.

Kind of was my thoughts. Up to 69k is more common to be distributed around some neighborhoods, but over 300k lines are usually more isolated from people.

It actually has some benefits... sometimes the utility doesn't care if you extend your yard into the right of way as long as you don't build structures and prices are a little cheaper. In some towns the only place where you can get a big back yard is next to a right of way. Lineman don't have a higher rate of cancer than any other type of profession so I can't see how living near transmission lines can be harmful.

Whenever working with a guy that has never been on transmission, it's always fun to grab something grounded and touch them on the nose. Like meter nerd said, everything else is grounded and you hold a charge when working out of an insulated bucket so a nice slow touch on the nose will put a nice scare into someone.

Definitely need to put more thought into what building materials before hand like what was mentioned before. There's things to do to help it, but you can't stop it completely.

I take it your location "NE" means Nebraska. Don't try to tell me it is hard to find a big back yard in about 99% of the state's area.

NPPD (the largest power supplier in the state) is currently in the process of planning a 345kV transmission line in which I live in their study area of where they wish to run the line. Part of their criteria for location of this line was that no dwellings will be within 300 or 500 feet of the line (can't remember which distance it was but am leaning toward it being 500).

 

[ggunn]

Lineman don't have a higher rate of cancer than any other type of profession so I can't see how living near transmission lines can be harmful.

If you live near transmission lines you spend a lot more time near them than a lineman does. Whether or not that makes it harmful, I dunno.

 

[Sierrasparky]

It actually has some benefits... sometimes the utility doesn't care if you extend your yard into the right of way as long as you don't build structures and prices are a little cheaper. In some towns the only place where you can get a big back yard is next to a right of way. Lineman don't have a higher rate of cancer than any other type of profession so I can't see how living near transmission lines can be harmful.

Whenever working with a guy that has never been on transmission, it's always fun to grab something grounded and touch them on the nose. Like meter nerd said, everything else is grounded and you hold a charge when working out of an insulated bucket so a nice slow touch on the nose will put a nice scare into someone.

Definitely need to put more thought into what building materials before hand like what was mentioned before. There's things to do to help it, but you can't stop it completely.

keep drinking that kool aide

 

[JoeTroubleShoot]

I take it your location "NE" means Nebraska. Don't try to tell me it is hard to find a big back yard in about 99% of the state's area.

New England.. Boston specifically. I suppose it would be hard to find a small yard in Nebraska. I wouldn't seek out a house near transmission lines, but it wouldn't deter me from buying.

I'm not making a case for living there, just saying I wouldn't be against it. I know a handful of people through work that actually prefer it. It wouldn't be my preference, but I wouldn't deny a nice deal by a right of way.

 

[arion]

that place is a deathtrap for anyone with a heart condition, or a medical electrical device or implant.just fueling a lawn mower on the property sounds like a good way to die in a gas vapor explosion.... im serious whoever approved building in that area is a fool. 60Hz electrostatic fields are more damaging to your health than any other frequency of electrostatic field. and i do not think homeowners insurance will cover the replacement of the electronics in that house. no off the shelf pc will boot in a emf field of that magnitude i just had a job with a situation where a local substation 750kv network feeder was ran on the other side of the wall from the IT room. it was shielded by the concrete wall and about 40 feet of dirt but nothing on the racks on that wall would boot and everything else in the room would lock up. the feeder could not be relocated. the fix was to install military grade hardened servers and workstations and near field emp suppressive cabling in the entire facility. the client was Google, and the final bill for that job was $18.7M.