No EMF Controller 24V, 30A or more?

estes53

Is there such a thing as a, No EMF Controller 24V, 30A or more?

estes53

Re: No EMF Controller 24V, 30A or more?

Or is it possible to use multiple controllers?

Cariboocoot

Re: No EMF Controller 24V, 30A or more?

What does "no EMF" mean?

estes53

Re: No EMF Controller 24V, 30A or more?

This is an example of what I would like to buy, but I need to control voltage from 5-100w panels, so need more amperage. -

On-line Description-
The ASC 24/16-A solar charge controller from Specialty Concepts.
It generates zero EMF (Electromotive Force), is temperature compensated, and very reliable.
It can handle up to 190 watts of solar panels;
multiple chargers are used for larger systems. (this is why I asked about multiple chargers, because they say this, but in my research I haven't seen anyone doing it.)

estes53

Re: No EMF Controller 24V, 30A or more?

http://en.wikipedia.org/wiki/Electromagnetic_hypersensitivity

I have a lot of the symptoms of this and figured that since I am planning an off-grid system (eventually), why not make it zero EMF and see what happens.

Cariboocoot

Re: No EMF Controller 24V, 30A or more?

Either it has been too long of a day for me or this makes no sense whatsoever.

Electromotive force is something you get from a motor powered by electricity, not a charge controller.

EMF sometimes stands for "Electro-Magnetic Field" which nearly anything with electricity flowing through it generates to some extent.

PV puts out current primarily, you don't really 'control Voltage' with a charge controller you regulate battery Voltage by switching the current source on and off.

Normally a controller is designed to handle a certain amount of current at standard nominal Voltages of 12, 24, or 48. There are many charge controllers capable of handling 30 Amps or more at any of the system Voltages.

It is possible you're looking at a linear current booster for running motors directly from solar panels, which is another issue.

But to tell the truth I've been up since 5:30 this morning, have done way too much today, and have had to correct about a dozen typos in my own post - so don't go by me.

estes53

Re: No EMF Controller 24V, 30A or more?

Electro-Magnetic Field, is probably correct.

My electronics training was with the military in 1978 and for whatever reason they taught "Electro-Magnetic Force".

estes53

Re: No EMF Controller 24V, 30A or more?

Ok, found this at Blue Pacific Solar-

Charge controllers are solid-state electronic devices used in nearly every solar and wind energy system that uses batteries. A charge controller is often times used in off-grid solar systems with 12 volt to 48 volt battery banks to keep the voltage to the batteries within acceptable limits. A charge controller automatically tapers, stops, or diverts electrical power when systems batteries become fully charged. Charge controller capacities range from 4 to 80 A and multiple charge controllers can be used in parallel for larger solar battery systems. Some charge controllers offer additional features, like charge status display, data logging, automatic battery equalization charging and generator starting.

Can anyone verify?

Cariboocoot

Re: No EMF Controller 24V, 30A or more?

Verify what? That there are charge controllers capable of handling anywhere fro 4 Amps to 80 Amps? Yes; our host has plenty of them: http://www.solar-electric.com/inverters-controllers-accessories/chco.html

Verify that they can be used in parallel? Most certainly; it's done all the time. For really big systems the MidNite Classic line is best for this as it has a "Follow Me" function which slaves the other controllers to one master that 'sets the rules'.

As for how much EMF or RFI any of them produce, that is quite another issue. Multiple controllers would in fact produce more because there's more of them and more wiring to radiate the RFI.

500 Watts of panel would not require multiple controllers. On 12 Volts it would be about 32 Amps, and at higher Voltages it would be even less current. Very easily managed. I've got 1200 Watts on one 60 Amp controller @ 24 Volts and have room to spare, so to speak.

BB.

Re: No EMF Controller 24V, 30A or more?

If you think you have sensitivity to EMF--Do you know what specific frequency ranges/types of fields that affect you?

For example, does a steady state magnetic field have an affect (DC Current flow, simple magnet, etc.)?


There are low frequency magnetic fields (60/120 Hz from AC power lines, upwards of 10kHz from various power switching gear)?

And there is the higher frequency stuff, from 1 MHz to >> 1 GHz?

Each has its own issues, and different devices generate different amounts of each.

-Bill

Cariboocoot

Re: No EMF Controller 24V, 30A or more?

And if you don't know you can find out, although the experiment is not simple or cheap. Basically you have to live inside a Faraday cage for several days. First with absolutely no EMF to see if the symptoms subside, thus determining that the EMF may indeed be a factor. Then with various frequencies and intensities to determine which, if any, has the most effect.

The concept is much debated in medical and engineering fields because no one has ever done extensive testing of this type (that I've heard of at least) and there is no known mechanism that would explain why EMF would effect a body (the closet would probably be possible interference with bio-electrical processes such as the nervous system).

I'm glad I do not have this condition as I have been exposed to every type and intensity of EMF there is for many decades and am none the worse for it. Now falling trees on the other hand ...

mike95490

Re: No EMF Controller 24V, 30A or more?

seriously, maybe you should be looking for candles. If you use electricity, you have to control it. When you control it, you create a "disturbance in the the Force".

So there are 3 basic types of controllers:
Shunt - when the voltage of the batteries rises, it disconnects the charge source, or it connects a heavy load till the voltage drops.
Frequency 1-30 Hz Very primitive, not at all efficient, short battery life, like a voltage regulator on a pre 1960 automobile.

PWM Pulse Width Modulation When batteries are low, stays connected (DC), as they approach full, the PWM starts to cycle ON & OFF sort of controlling the charge to the batteries. When panels are well matched to the battery bank, they can be 80% efficient, otherwise only 70%. Charge regulation can be very good. Frequencies 1-10,000 Hz changes according to the charge & loads

MPPT Maximum Power Point Tracking. Best thought of as a DC transformer, to efficiently match panels to batteries. Greater than 95% efficiency. As battery approaches full charge, it drops the MPPT method and falls back to PWM mode to maintain Float voltage. Frequencies 1-40,000 Hz

Higher efficiencies = less losses wandering around in the air or as heat

And then there is the AC inverter, which produces 60 & 120 Hz signals.

You may have to rent or buy a meter, and test several types under varying conditions to select something you like.

Or you can mount the power gear remotely from your house/bedroom, install a metal foil (steel or iron is effective on magnetic fields) sheet on the wall near the power center. Or candles.

westbranch

Re: No EMF Controller 24V, 30A or more?

EMF or what ever, I do not know but this falls into 'if I hadn't seen it with my own eyes I would not have believed it!"
Over 40 years ago, my godmother used to ask me to please 'fine tune' in her colour TV.
The reason was that if she got within 5 feet of the TV it started to display all kinds of unwanted lines etc, some straight some wavy. (Remember those old CRTs?) The closer she got the worse the picture. Me, no problem, no interference...???
Strange, but true.
Oh, and her radio was similarly affected, but less sensitive and getting right on radio signal was possible for her most of the time...

JDark

estes: I too am electrosensitive. I have planned to buy a trailer and make it off-grid w/ low emf solar for sometime now.

Solar systems by generally are high emf beasts. The array emits-put as far from living area as possible not on the roof to help that. No inverter 12v DC only. Inverters are the worst offenders in the system. I have a couple items that Require AC and can not trade them out as I did the rest for DC or use converter adapter [I am going to shield those adapters later]. The AC appliances I must have are used about a minute a day: food processor, copier and blender. I will use a portable inverter to make the smoothie or copy and then disconnect it when done. I will be shielding it in mesh as well.
The last issue I have not resolve is this one of controllers. The 2 main technologies on the market are to be avoided. They are PWM and MPPT. From a solar design perspective they make for a good dependable system. From an ES perspective they are dangerous. I love peanuts-they are good for me. For someone allergic to them they are deadly. I am not sure though if the level of EMFs that most of the standard solar systems put out is not generally bad for health.

There is no place to take the trailer that I would not have to be hooked to a smart meter. So solar it is w/ a low emf 12V DC only system. Today I am now in the throws of it. I have the trailer. I have picked the panels. And now the same issue for the controller. I have used the eiwellspring site for a guide on low emf solar-most ES folks know this site. It's a good guide but WARNING there is lots of mis-information there! First of which is that ASC specialty concepts controller. It is a high level of EMFs! It is a PWM controller just like the rest. I was wanting to use that until I saw that on the specs the store had posted. The other option the site recommend was the 7 amp sunforece [total garbage as their controllers fail at the least every 4 months or more]. http://www.amazon.com/Sunforce-7-Amp-Charge-Controller/dp/B0006JO0XII spent all day Thurs on the phone and online and found A 10amp version of the same thing made by a better quality company WirthCo. http://www.wirthco.com/volt-solar-controller-23122-p-1161-l-en.html My installer informed me I can not use that as more than one can't be hooked together. He recommended a larger 30 amp sunforce and after reading the reviews, found it has the same fail rate as the 7 amp. Not worth it best to just be stuck w/ only 100 watts w/ 1 WirthCo 10amp and then I at least know my propane fridge will ignite and my water will pump and get 1/2 of computer or TV only a day or an hour of reading light. No cooler and that would be touch in the S. of Arizona. I could scrape by on 200 watts for a while, but not 100.

Yesterday the installer agreed to call WirthCo as they said they would tell him how to make what I need work. I called them back again about their larger unit and they said it was not PWM or MPPT, but it is digital and may be a problem for me and should stay w/ the small ones. Seemed all good and well, till this morning. I received an email from the head of the university solar dept- I have been sending him links of what I am working on and he gives his thoughts. He knows nothing of the fact my installer said it could not be done, only the link to the controller. His reply to that link: " You probably cannot use two charge controllers on the same battery bank. They will interact and may cause battery over charging on undercharging. You will need a single charge controller that can handle the output of both of your modules. It should be rated at 12 amps minimum for two of the 100 watt modules.". He is familiar w/ ES and can think out of the box for what we need.

The last thing I have checked into is maybe getting something like this built: http://www.eiwellspring.org/offgrid/VoltageSwitchChargeControl.htm In my area workmanship and service is non existant so the best local VCR repair place will probably say not a chance. I may try to see if someone in AZ can do something of the like.

I hope someone here will come up w/ an answer to this as well. I was thinking about posting about this myself, but most of the solar industry have no clue about what is safe for ES and are not going to understand and will try to push us into using things that will hurt us. There are always exceptions of course.

Also want to note that: I have found some aids that do not require power: tiny battery operated sewing mach and led candles that make beautiful bathroom lighting. When funds are available I will add more candles and battery or solar fairy/rope lights. Really only need full light to read, cook or do other task where seeing detail is important!

BB.

If you are trying to reduce electrical noise--MorningStar Prostar and TriStar (PWM) Families have a "Telecom Mode" jumper. Basically, most PWM run at hundreds to thousands of Hz (cycles) per second and generate a fair amount of higher frequency radio noise.

The telecom noise slows the PWM cycle to below audio frequency--Depending on the frequency of RF noise you are sensitive to, this may be a good solution for you.

Otherwise, you can go the other way. Get a high quality MPPT type charge controller such as from Midnite (and I think some models of MorningStar MPPT controllers) that have FCC class A or Class B rating. They usually have lower radio frequency noise (FCC regulations are concerned with >30 MHz of RF interference).

-Bill

JDark

I picked what I am going to use for a controller. This was really the only solution I feel comfortable with. http://www.solarconverters.com/index.php/products/92-voltage-controlled-switch/126-vcs-1ah-or-vcs-1al The eiwellspring article in my above comment tells you how to put this into application. He too is electrosensitive and though some of the info on his site is wrong, I did find this article to be right on. Seems to me to be the safest option and workable w/ larger system. This method is NOT normal by industry standard, but does the job I am going to need in a way I can tolerate. Our "host" sells this switch that is mentioned in the article, made by solar concepts and I got the blocking diode, heat sink fins and capacitor from electronics place. All takes assembly, but what doesn't these days.
So now you can file and book-mark this away for when you want or need to build a system and not have to go on a mad search with the installer standing at your back door.LOL

I also like that you can set you own setpoints on this-as all batteries are not the same. I have read reviews about the 7amp switches turning off before the batteries are completely full [ie at 14.1volt vs 14.5 volts].

Hope this helps.