Electromagnetic radiation - looking for info

[Sunking]

Radios are extremely sensitive to EMR and are not a reasonable test of how noisy a solar inverter is..

Radio equipment is not sensitive to EMR, wrong term, Radio is sensitive to RFI generated by the Inverter. Solar panels do not generate any kind of radiation because they are DC.

EMR is waves which requires oscillation or AC currents and is a very broad term to encompass all sources of radiation from sound (air),Magnetic from low frequency power, Radio Light, to Ionizing radiation of X-Rays and Gamma Rays

[sdold]

I make these measurements sometimes as part of my job, the equipment is pretty expensive and needs to be calibrated once a year for about $2000. I've seen some cheap field strength meters meant for the tinfoil hat folks that are calibrated really strangely, having no correlation to the industry or government standards.

Anyone want to guess where this is?

photo 2.JPG HC MPE.jpg

[solarix]

So please, what are your conclusions in measuring solar inverters?

[SunEagle]

All electronics emit a certain amount of RF. They all go through testing and get a passing grade by the FCC if they stay below or within certain frequencies and power output.

If they stay within the regulations specs for other forms of transmissions on the electrical distribution lines (harmonics, noise, transients, etc) then they get a passing grade by meeting certain IEEE regulations.

Inverters are just one type of electronics that must meet both FCC and IEEE regulations to be used in the US and other countries that have similar rules.

As for the question asked by sdold. My guess would be in his backyard.

[sdold]

Solarix: I haven't measured any solar inverters, I measure radio transmitters. But if anyone's interested, I will try to measure a couple of inverters this weekend. Suneagle: I wish it was my backyard, but it's actually a very popular California tourist destination.

[Sunking]

Anyone want to guess where this is?

No guess it is a Gauss Meter.

[Mike90250]

Palm Tree, Spanish Mission land, San Diego, Santa Barbara, Palm Springs ?

[sdold]

It's the Hearst Castle on the central CA coast. There is a 100 watt VHF weather transmitter on the roof of the building I am standing near, serving boats out in the ocean, so they sent me down to measure areas around the antenna to make sure it didn't exceed Maximum Permissible Exposure (MPE) limits. I might measure a couple of inverters this weekend, but I don't think it would mean too much because every inverter is different. I need the practice though since I don't do it that often.

[SunEagle]

It's the Hearst Castle on the central CA coast. There is a 100 watt VHF weather transmitter on the roof of the building I am standing near, serving boats out in the ocean, so they sent me down to measure areas around the antenna to make sure it didn't exceed Maximum Permissible Exposure (MPE) limits. I might measure a couple of inverters this weekend, but I don't think it would mean too much because every inverter is different. I need the practice though since I don't do it that often.

nice gig.

[sdold]

I measured a few inverters in my neighborhood, with a 5-300 MHz H-field probe and a 500 KHz to 1.5 GHz E-field probe. Part 15 gives limits for a 3 meter distance, but none of the inverters measured anything (E or H) at that distance, but a couple did go up to around 100-200 mV/m if I moved the probe to within a couple of feet of the inverter. I wasn't able to read anything with the H-field probes, even up to a couple of feet from the inverters, and that probe goes down to 0.1 A/m.

I guess this is expected since (I assume) they have to meet Part 15 limits, and also I'm not certain this is the best tool for this, since it's main use is around transmitters, but it was nice to get out and meet some of the neighbors.

e-field at 3 meters.jpg H-field at 1 meter.jpg close e-field.jpg

[bcroe]

Thanks for the report, which I interpret as supporting the idea that inverter emissions are far, far below dangerous. Bruce Roe

[sdold]

I think you could say that. For comparison, the maximum continuous E-field strength that is allowed by the FCC in uncontrolled (publicly-accessible areas) areas around radio transmitters from 30-300 MHz is 27.5 V/m. You could get that a few feet from a 100 watt transmitter, but I don't think you'll get it from a solar inverter.

[TomP]

Thanks for the replies. More info: There is currently an old 70's home made off grid system we are using at this home for now. (we just bought the home) Is there a testing device I can purchase, rather than use a radio? If the radio makes static, then what?

About the only thing 70s in that house is wiring and outlets. The age of the house has nothing to do with your issue. Mine is 33 years old, gear has morphed form no inverters to the massive units we have today. As stated above, I would put my concerns on cell phones first, of course todays phones are not near as powerful as they used to be. Personally I would be far far more concerned with what you are eating.

[SunEagle]

About the only thing 70s in that house is wiring and outlets. The age of the house has nothing to do with your issue. Mine is 33 years old, gear has morphed form no inverters to the massive units we have today. As stated above, I would put my concerns on cell phones first, of course todays phones are not near as powerful as they used to be. Personally I would be far far more concerned with what you are eating.

Don't forget about going outside without using sunblock. Those UV rays are down right nasty to your skin.