20kv recovery station, is it a health hazard for immediate area?? 2

[10101001]

hello engineers, i have a question .
what effect would a recovery station that is power at 20 KV and 50 hz from the local power line would have on the immediate area around it? i mean i know it will produce some electromagnetic field around it, and that is not that good for the rezidents living next to it. I know that those things should be built NOT in a rezidential zone...they need it because they extend the infrastructure of the public transportation sistems .
The station is being built at max 5 meters from a house and there are houses all around it. I know that it's not HEALTHY for the inhabitants of the area. What i`m asking is, is that station a health hazard for the inhabitants living next to it? (i dont know what data i need to know in order to calculate the intensiti of the field at difrent points around it, and even if i knew how to do that , wich i will find out, i wouldn`t know what intensiti is damaging over time for the healt of the people)
The person living at 5m from that station already sued the local city hall..well not city because we live 10 km from a citi and we have a local hall, but the thing is i dont know if he`s gonna win the case. I live 3 houses farther away from the station so i have a particular interest in that case. IF this is a health hazard i will support and make sure he wins the case. BUT in order to do that i need to make them REALIZE WHY they should support me (to explain i need to understand it myself, that`s why i`m asking for your help) ...please if some1 could answer this post you will help me and my community greatly.

 

[dpc]

What's a recovery station?

Concerns regarding health risks from EM radiation associated with power systems were pretty much disproved 20 years ago. Correlation, if any, is very weak when other factors are eliminated. Power distribution in the 15 to 25 kV range through residential areas is very common, at least in the US.

Bus since you already KNOW that it is not healthy, I'm sure you can find plenty of "facts" to the contrary in various corners of the WWW.

 

[rcw retired EE]

I am not an expert in this area but I am very interested in it.

My home is adjacent to a 230 kV transmission line and a gas pipeline. That pipeline has killed more people than the electrical lines. The transmission line does not concern me. I worked many years in substations and high power rectifier stations that had large magnetic fields with no known health effects. (I could not wear a watch to work, the strong magnetic fields would affect the mechanism. My pocket knife could hang from the metal handrail by our desk due to the induced magnetic fields).

If you are concerned about magnetic fields, make sure that you do not go near a television set, a CRT computer screen, an electric oven, a toaster or other electrical equipment in your home. The fields from appliances are typically stronger than the field from a substation due to your proximity to the appliance.

My research has not located a study that substantiates a health hazard from 50 - 60 Hz magnetic fields, even though many researchers have tried to find a link.

As Dave said, you will be able to find all sorts of unsubstantiated "studies" with claims of health hazards. If there really is a health hazard a lot of us old timers wouldn't be around.

 

[itsmoked]

Besides, 20kV is about as low a voltage as you an find in substations these days.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[marks1080]

The low power high frequency radiation from the cell phone you hold next to your brain should be a bigger concern for you....

 

[ScottyUK]

Get a foil hat. All power plant workers wear them, you just can't see the foil because it is inside the safety helmet. How do you think we live so long?

 

[Skogsgurra]

Be nice to 169!

He IS concerned. And nothing wrong with that. Unfounded rumors have that effect on many people.

But there's no reason for the concern. Just as little as there is a reason to fear that little pink angels pea in your orange juice at night. Or, being kidnapped by extraterrestrials.

Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

 

[waross]

What's a recovery station?

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[davidbeach]

Somehow I kinda doubt that our OP is really an engineer.

 

[cuky2000]

The EMF emission of power facilities and the impact in a human health is a controversial issue that application engineers are uncomfortable to discuss since researchers do not provide objectives evidence in favor or against it. Follow the precautionary recommendations of recognized serious organizations specialize in this subject matter could be a reasonable good approach.
The good news of EMF is that a short distance from the source the effect decay very fast. Also metallic and grounded object including the substation fence act as a reflector that mitigates the effect of the EMF strength.
If you are concerned with hazardous nearby substation, step and touch potential in the event of a ground fault in the station need to be analyzed to determine if there is any serious concerns.
Also an explosion of a power apparatus such as oil filled transformer or noise emission could be sources of potential concerns for residents at close proximity of the substation.
For reference, there are safety standards and public safety regulation that utilities should follow. Check what is applicable in your country or locality agency that regulate those public safety issues.

 

[crshears]

What's a recovery station?

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]

 

[tinfoil]

The fact that the OP's handle is a binary number suggests he/she works in the information or computing industry.

Assuming that they did not dictate their post over a cup-string-cup interface to someone else, they sat in front of a monitor near a AC/DC switching power supply in a PC of some sort. Probably in a building lit by compact-fluorescent lights, with assorted radiating devices like ipods, radios, and TVs nearby.

They are asking about the impact of a 20kV station of some sort 4 building lots over from where they live.


So I can answer with almost perfect confidence that its existence represents NO increased risk to their health.

 

[jghrist]

It's also interesting that the OP shouts "PLEASE ANSWER" and then after three days does not tell us what a recovery station is.

 

[cuky2000]

The word "recovery substation" not recognized in the power community. However, other outside the power the field or perhaps a translation glitch could call a mobile station or mobile transformer using somehow the terminology "rapid recovery" as shown in the link below.

Judging by the voltage level (20 kV) and the proximity of housing (in meters), appear that this is a distribution substation outside the US.

The Recovery Transformer (RecX) project

http://www.abb.com/cawp/seitp202/c838625f4d7a38e4c1257a92001e9b8a.aspx

 

[Skogsgurra]

cuky2000

We are not "uncomfortable to discuss" the matter.

But, there is no need to do so.

There are enough studies carried out by enough organisations to know wih certainty that VLF E and H fields with strengths that are met in electric switch-yards and transformer stations have no impact on living matter.

The recommended maximum H field (B,actually) in Sweden is .2 uT. I once contacted the authorities and asked why this limit had been chosen. Other countries have 60 uT for skull and 300 uT for body and I wanted to know why we sturdy and robust Swedes wuld be so much more sensitive in that respect.

I didn't get any explanation. But after a few weeks I got a phone call from a professor at the Karolinska Institute (they decide who shall be given the Nobel Prize in Medicine each year). He told me that it was derived mathematically!!!

I was both surprised, and not. I had expected that answer because .2 uT is what you get when you plug 1 A and 1 m into Biot-Savart's law. But I was surprised that no-one had bothered to find out if there was any physiological ground for that "mathematically derived" limit.

I feel somewhat ashamed for the Karolinska Institute - and for humanity in general.

So, we are not uncomfortable at all. But everytime you start any discussion on this matter (or "anti-matter") there are people like 169 (13² - not so fortunate) that think about the proverbial smoke and fire. So it is best not to talk about it at all.


Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

 

[ScottyUK]

Gunnar,

There is an EU directive which will impose limits on exposure to both electric and magnetic fields. You (and others) might be interested in the following:

http://www.hse.gov.uk/radiation/nonionising/directive.htm

http://www.emfs.info/limits/limits-organisations/eu-2013/

We did some measurements* at the power plant where I worked and from memory the only areas where magnetic field intensity gave cause for concern was close to the generator endwindings and near the bushing cubicles of the IPB between generator main termianls and the GSU and auxiliary transformers. Neither were locations where a worker would spend a significant length of time.

* The reason why we ended up taking measurements was that a scaffolder inadvertently formed a closed loop around a section of IPB outside of the main bonds where the flux cancellation is poor: scaffs are a hardy breed but he was shaken when the tube he was holding got hot in his hands and then sparked when he broke the loop. We were asked to quantify just how powerful the field was, and whether it posed any health risk.

 

[Skogsgurra]

Yes, Scotty!

Definitely interested! I wasn't aware of the EU Directive from 2013 because "Frankly, my dear, I don't give a damn", as Rhett Butler used to say.

And I think that I was perfectly right ignoring those limits. The older limits (60/300 uT absolute limits) have now been replaced by a general limit at 100 uT, where no action at all is needed and a "fuzzy" range between 100 and 1000 uT, where it seems that some supervision is recomennded.

Between 3000 and 6000 uT (head) action may be necessary "if workers report symtoms".

That is all a far cry from the limits that were used before. BTW; 18 000 uT is considered Little risk for limbs. So, you can do work inside a coil without risk - as long as you don't stick your head there.

I have been working on a 400 Hz inductive furnace with an enormous stray field. We measured 52 uT in the operator's room. No problems with the operators, but huge problems with the Ethernet. We measured 23 A in the coaxial cable's screen and had to provide parallel paths using 2x16 mm² Cu wire bolted to the taps along the cable.

There was a fence around the furnace. It melted down first time the furnace was running. It is now a plastic fence.

And, that professor at the Karolinska Institute doesn't say much about his 0.2 uT limit any more.

BOTTOM LINE:
There has never been - and there will never be - any risk with ELF fields. Be they H, E or B fields.



Gunnar Englund

http://www.gke.org

--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

 

[cuky2000]

Hi Gunnar,
I should say that "I fill uncomfortable " and discussing with other colleagues they do not fill comfortable on the subject either. For example, recently our firm represented a client to obtain the license of a large power project. For common consensus we do not want to take the risk to be considered unqualified, we decided to use the service of scientific organization specialized in the subject to discus the EMF issues in front of a court.

Although power engineer could have an opinion on the subject, I prefer let subject matter experts dealing with epidemiological health risks from exposure to the extremely low frequency (ELF) electric and magnetic fields (EMF).

This is because still there scientists with judgments close to the dividing line between believing and not believing that exposure to ELF can only have very weak evidence to suggest that it could cause health risk. Other are “prone to believe” that EMFs cause some degree of increased risk.

Considering the quote below still we can see indication of word such as "unknown risk" that may me fill uncomfortable to insure others to purchase a house next to a substation or power lines. Definitely I will not purchase a house next to a substation...otherwise I have to think in a new wife.

...In summary, the 99.2% of children residing in homes with exposure levels < 0.4 microT had estimates compatible with no increased risk, while the 0.8% of children with exposures >/= 0.4 microT had a relative risk estimate of approximately 2, which is unlikely to be due to random variability. The explanation for the elevated risk is unknown, but selection bias may have accounted for some of the increase. ....._{Division of Epidemiology, National Institute of Environmental Medicine, Karolinska Institute, Sweden}.

 

[ScottyUK]

cuky2000,

The CEGB was the UK's nationalised generation and transmission industry until it was broken up for political reasons. A study of about 86000 employees and former employees was undertaken to investigate the health effects of working in the UK's generation and transmission industry. Given the wide range of activities and hazards within the sphere of the organisation's interests, the following papers might be worth tracking down:

http://www.emfs.info/research/abstracts/cegb-cohort-abstracts/

From a glance over the abstracts the increased risks appear to be skin cancers due to working outdoors, and asbestos-related diseases. Leukaemia and brain cancers weren't noticeably increased by within the industry.

 

[jraef]

OMG, I thought I was the only one who sees the little pink angels peeing in my orange juice at night! I thought it was just because I too live almost right under a HV transmission line (just recently boosted to 230kV), but now it appears these must be REAL!

Aaaaaarrrrgh!

Seriously though, thank goodness for the tin foil hat crowd making this a big deal because when I bought this house 17 years ago, the fearmongering made multiple buyers get cold feet, so I got it for a song. Now that the hysteria has abated and the housing crises as reversed itself (at least around here), my house it now "worth" 4x what I paid for it in 1997.

"Worth" being a relative concept. It's the same crappy house I bought then, now 17 years older. But someone just paid that for an identical house down the street, also with the same 230kV lines in the back yard.


"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington