[RE-wrenches] Inverter causing migraine?

Thu Feb 4 17:47:56 PST 2010

Hi Ron and the group,

The attribution of negative health effects to exposure to electromagnetic 
fields or activated electric equipment has not been confirmed in random 
double-blind provocation studies involving persons reporting 
hypersensitivity to electricity. Before we accuse are hard-working 
inverters, let's look at some facts. There are 13 different categories of 
headaches which are divided into over 129 sub-types. Many people call every 
headache they experience as migraine when in fact there are specific 
inclusion criteria to make diagnosis of migraine. The "rubber band 
tightening around my head" is a classic symptom of tension-type headache. 
Given a mid 50's female, there are more likely one or more provoking 
factors: medications, sleep pattern, hormonal replacement therapy, stress 
(clenching, TMJ), smoker, foods (aged cheese, alcohol, caffeine, chocolate, 
dairy products, MSGs, etc). Does she work at a computer using a chair with 
no arms and no lower back support with a monitor slightly higher than eye 
level? This is an extremely common scenario in which the employee comes to 
work symptom-free and by 12 or 1:00 develops a headache or neck ache. If she 
really wants some answers, she will need to keep a headache diary for 
several weeks and seek professional help. You could cycle the inverter 
on/off to see if there is a direct correlation between the incidence of the 
headaches and runtime of the inverter. BTW, the placebo effect, as mentioned 
in other emails, is between 40-60% effective at resolving symptoms. Hope 
this helps a bit.

Mike
Michael Gullo
Solar Solutions LLC
Marlton, NJ

NABCEP Certified PV Installer T
Diplomate American Board of Orofacial Pain

----- Original Message ----- 
From: "Ron Young" <solareagle at solareagle.com>
To: "RE-wrenches" <re-wrenches at lists.re-wrenches.org>
Sent: Thursday, February 04, 2010 1:19 PM
Subject: Re: [RE-wrenches] Inverter causing migraine?

> Bob,
> Not a customer, an employee who works for me. She is mid 50's and has 
> very good hearing. You may be right about sound. I also think there's  a 
> significant portion of psychosomatic in the mix but I wanted to find  out 
> if there were other instances of people experiencing distress from 
> inverter operation just to rule out the possibility -or take it into 
> account.
>
> I know that some people are becoming more sensitive to environmental 
> influences but this inverter is quiet, just the usual fan sound 
> occasionally. I used to be able to hear the sound of an ultrasonic  alarm 
> system back when I was in my 20's & 30's - now I just hear  ringing in my 
> ears.
>
> Ron
>
>
> On 4-Feb-10, at 1:30 AM, boB Gudgel wrote:
>
>>
>> Dan Fink said:
>>
>> "That's a tricky situation. There are only two possibilities for  what's 
>> causing the problem; sound or electromagnetic radiation"
>>
>> I'm betting that it's sound.  Remember how you could hear  televisions 
>> singing
>> away at 15 kHz ??  That still gives some people headaches.
>>
>> How old is this customer ??   I'm guessing he's young because it's  most 
>> likely because he
>> can hear the inverter switching.    We just can't normally hear  them.... 
>> The FX/VFX
>> inverters switch at around 20 kHz which some people can still hear. 
>> Especially younger ones
>> with better hearing.
>>
>> It's probably the transformer windings and iron acting as a speaker/ 
>> transducer.
>>
>> High frequencies are very directional so will usually respond well  to a 
>> thin wall  of
>> padding between inverter and the rest of the inside of the house or 
>> cabin.
>> That should help reduce the acoustical output.
>>
>> boB
>>
>>
>>
>>
>>
>>
>> Dan Fink wrote:
>>> Joel --
>>> Good points. In a recent newspaper article in Boulder, CO about a 
>>> really bad PV install, the direct grid tie inverter was mounted  right 
>>> on the outside of the wall from the homeowner's bed. They  finally had 
>>> to have it moved--mostly because of buzzing, but EMF  was a concern too. 
>>> It was basically less than a foot from the guy's  pillow.
>>>
>>> Also, I forgot to mention that there are fairly inexpensive EMF  meters 
>>> available from the same places that sell DIY shielding  materials.
>>>
>>> The biggest source of EMF at *my* house is actually the E-Meter 
>>> measuring amp-hours. It even interferes with my handheld ham and  fire 
>>> department radio FM communications on 2 meter.
>>>
>>> DAN FINK
>>> Renewable Energy Consultant
>>>
>>>
>>>
>>>
>>> Joel Davidson wrote:
>>>> Ron,
>>>>
>>>> Electromagnetic fields are produced any time you have current  flowing 
>>>> through wire. They are low frequency waves that drop off  rapidly 
>>>> proportional to the distance from the source. Inverters,  transformers, 
>>>> fluorescent light ballasts, motors, clock radios,  power blocks, 
>>>> microwave ovens, kilowatt hour meters, service  panels all emit EMF. 
>>>> There is no
>>>> practical way to block EMF.  It passes through almost everything 
>>>> including walls and even lead. There is no U.S. safety standard  for 
>>>> EMF. Some say 8 milligauss or more is dangerous and 2.5  milligauss or 
>>>> less is safe.
>>>>
>>>> I went through our home about 10 years ago using a borrowed  milligauss 
>>>> meter (thanks David Katz). Our utility meter service  had significant 
>>>> EMF, but that was not a problem since it is  mounted on an outside wall 
>>>> and there is a closet between the  living space and the meter. The EMF 
>>>> had fallen to below 2  milligauss between the wall and the closet door. 
>>>> The bedroom clock  radio was the second largest EMF source in our home. 
>>>> Moving the  clock 1 foot away from the bed to the other side of the 
>>>> night  stand brought the EMF levels under 2 milligauss. Our SW4048 
>>>> inverter emitted a field that fell to a safe level 2 feet from the 
>>>> inverter.
>>>>
>>>> I tell people not to put their bed against the wall where their 
>>>> utility service panel or inverter is mounted. I also tell them  that 
>>>> the Japanese did a 2 year study of school children riding the  Tokyo 
>>>> subway (big EMF emitter) and found that there was no danger.
>>>>
>>>> Some sounds that most of us take for granted can cause physical 
>>>> discomfort and even pain. SW4048 and other transformer and  electrical 
>>>> and electronic buzzing can be annoying. Also certain  wavelengths and 
>>>> intensities of light can cause pain and injury.
>>>>
>>>> Joel Davidson
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