use and working of shunts

System

I've read many times gurus working with shunts in a PV application, what is their exact uses, and how do they work ?

thks, Jacques

niel

Re: use and working of shunts

shunts are resistances set in parallel to a meter measuring current (ammeter)to multiply the current capacity of the meter. that is, it could as an example be used to measure 100amps rather than 10amps. not just any resistance will work and power passing abilities have to be considered as well so in a case of you not knowing, it is best to using only shunts by the meter manufacturer or a company such as northern arizona wind & sun would recommend.

System2

Re: use and working of shunts

Thks Niel,
But for instance, how does that must be connected/works with the TRIMETRIC 2020

http://store.solar-electric.com/tm2020.html

or the Xantrex meter TM500

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One purpose, is when two different sources of DC  are both connected (PV & Wind Turbine) to the bank of bateries, I want to be able to know each of these inputs.

jacques

System2

Re: use and working of shunts

I have found this thread which can help me I think

http://www.wind-sun.com/smf/index.php?topic=988.0

and this link on Bogart site

http://www.bogartengineering.com/trimetric.htm

thks for yr help, but if you have another comment ...

jacques

halfcrazy

Re: use and working of shunts

Check out bogarts pentametric meter it has the ability to have multiple shunts so you could monitor seperate dc inputs but still have system totals at a press of the button it also has pc software to send the info to your pc.

arcandspark

Re: use and working of shunts

Jacques,  What the shunt does is use a very  very small voltage to power a meter which will show you how much current is passing through the shunt. Lets use a good ole analog swinging needle type meter as an example. We have solar panels producing DC power and we would like to see how much power they are producing. By placing this shunt in series between the PV panels and the charge controller we can see how much current we are getting from the panels. But we do not want to loose any DC power so the shunt is designed in such a way that is will usually only use up about 50 millivolts to 100 millivolts from the electical power coming from the PV panels. This is very small and we can live with that kind of loss. Most amp meters will state a Full Scale Reading Voltage, if you look close at the fine print writting on the meter face plate you may see F.S.50mV which means to get a Full Scale reading on the meter it will take only 50 millivolts. So you must also match the shunt to the meter you are using. If you use a 100millivolt shunt with a 50 millivolt meter the reading will not be correct. Some amp meters will have the shunt built inside th meter, but usually on large systems the meter will require an external shunt. The most important thing is that the shunt has the lowest resistant or OHMS possible, much less than one ohm. I hope this helps you better understand what it is used for. Just do a web search on How a DC shunt works and check it out.
(arcandspark)

System2

Re: use and working of shunts

Thks for the explaination, I see more the matter now.

But, you know, in Europe we are a little bit underdevelopped photovoltaicly speaking, and I fear it is impossible to find those of these electronical stuff ( speaking of these or of buck-&-boost converter is just insane  )

I may mistake, but I have not seen any of these electronical stuff for sale in the store of Northern Arizona Wind & Sun and I even know if they can forward to Spain.

Neither on the site of the Hornet wind turbine manufacturer, which give electronic schedules, but I am an Ass in the matter.

Where do you thing I may buy them easily without ruining me?

jacques