Wiring a shunt/ammeter into a 24v DC charger


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Old 11-05-17, 06:00 PM
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Wiring a shunt/ammeter into a 24v DC charger

I have a home made 24 V DC charger using an alternator run by an old snowmobile motor. It is used to charge my battery bank of my solar system during those poor sun days of November.
I recently purchased on EBay a digital display with a 100 Amp shunt which I would like to insert in line to record the charge in amps. I am currently using the charger at idle speed so as not to create too much current, and am using a computer fan to cool the alternator.
Can anyone tell me how to wire this. Thanks
 
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Old 11-05-17, 06:19 PM
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Welcome to the forums.

Model numbers or a picture would be good for confirmation.

Basic wiring of a shunt and ampmeter

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Old 11-05-17, 07:02 PM
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Shunts are normally wired into the negative conductor. This is especially true of the Chinese units and combination meters available on ebay.

Check out this page. https://www.google.com/search?q=wiri...w=1056&bih=652
 
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Old 11-06-17, 11:41 AM
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Personal preference. The amp meter will work in either plus or minus path.
 
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Old 11-06-17, 03:19 PM
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Neg side monitor is prefered in a car, due to potential shorts to frame. In large plastic boats, I see a lot of + side monitoring.
I just did some shunt wiring last week for industry and it was in the pos side of an ungrounded 125V dc system that fed 20A motor.
 
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Old 11-06-17, 06:22 PM
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IF it is just a simple analog ammeter then yes, it WILL work in either lead.

BUT, the original poster stated: I recently purchased on EBay a digital display with a 100 Amp shunt...

The wiring on every single Chinese-made DIGITAL ammeter I have seen, and I have seen several, REQUIRED the shunt to be in the negative lead due to the wiring for the DIGITAL meter power. Check out the link to the Google page I had included.
 
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Old 11-06-17, 07:03 PM
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Yes.... I see your point. I have seen these types of meters before and they are trouble. Here's two notes they've posted to the user.

  • Common ground design,the ammeter can only series connection between the test equipment negative and the test equipment power supply negative
  • Recommend to use a separate isolated power supply
 
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Old 11-08-17, 05:30 PM
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Thanks

Many thanks to the members who stepped up to help me out. Sorry for the delay in responding, had phone problems
 
 

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