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Thread: Installing an analog ammeter

  1. #1
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    Default Installing an analog ammeter

    Hi,

    Anybody here who knows how to install an analog ammeter to measure the current coming from the panels? I tried doing it by directly wiring the meter in series with the positive wire, it gives me a reading but it trips the controller after a few seconds. I heard from somebody that you ned to put a resistor and a diode so that it won't trip. By any chance anybody here knows if thats a true and if so, can somebody give me the diagram and parts needed?

    Thanks!

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    You need to buy a shunt (50a) but depends on what the aprox full amps you are likely to ever get from the panles.. its best to get a shunt size tso that your reading will be about half the shunt rating...wire it in series with the positive wire from the panels then connect a millivolt meter across the shunt to read the amps
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    Are you asking for a permanent meter or test meter?

    Both work the same way if using a shunt type meter. A shunt is a precision power resistor designed to develop 50 milli-volts at full scale reading.
    MSEE, PE

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    I added a 3' piece of #14 wire between the charge controller and the batteries. This is my shunt resistor. I calibrated it but snipping of bits of wire until it read the same as my 10 AMP multimeter. I think it's something like 0.002 ohms, so the voltage developed across this resister is 0.024 volts. THen you just need to buy or make a meter that will sense this voltage.

    Or you could just buy this for 15 AMP DC ammeter for 8$

    http://www.mpja.com/prodinfo.asp?number=17254+ME


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    Quote Originally Posted by Sunking View Post
    Are you asking for a permanent meter or test meter?

    Both work the same way if using a shunt type meter. A shunt is a precision power resistor designed to develop 50 milli-volts at full scale reading.
    I'm planning to make it a permanent meter to constantly measure the current my panels are giving.

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    Quote Originally Posted by john p View Post
    You need to buy a shunt (50a) but depends on what the aprox full amps you are likely to ever get from the panles.. its best to get a shunt size tso that your reading will be about half the shunt rating...wire it in series with the positive wire from the panels then connect a millivolt meter across the shunt to read the amps
    I have 4 pcs. 100watt panels @ 12v / 5.7a. Please pardon my ignorance, after I buy a shunt how do i connect my analog ammeter then?

    Thanks!

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    Quote Originally Posted by raymondalmeda View Post
    I have 4 pcs. 100watt panels @ 12v / 5.7a. Please pardon my ignorance, after I buy a shunt how do i connect my analog ammeter then?

    Thanks!
    This 30 Amp meter has a built in shunt. Just install it between the charge controller and the battery.

    http://www.mpja.com/prodinfo.asp?number=17679+ME

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    Raymondalmeda If you use a shunt you use a millivolt meter as shown in the simple drawing to read the amps usually 1a =1mv .if you dont use a shunt you just connect the 30a ampmeter as shown in the drawing where the shunt is. you dont need any diodes or anything else .

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    you could get an old automotive ammeter with 2 terminal lugs on it, those often have the internal shunt, but only read in 5A increments.

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    But Mike he may have trouble finding a 1948 Hudson Hornet to get the ampmeter..??
    Mabe it easier if he just goes to an electronics parts shop and either buys a 50a shunt and a millivolt meter or a 30a ampmeter,..

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