Author Topic: Combiner Box voltage and current monitoring  (Read 2335 times)

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Offline kosmonooitTopic starter

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Combiner Box voltage and current monitoring
« on: August 11, 2017, 05:34:02 pm »
Greetings,

I am rolling my own version of this device:

Billion SG3204S -   Solar DC 4 Strings Meter
http://www.billion.com/Energy Management/Solar Monitor Meter Series/Billion SG3204S


I am trying to figure out why they monitor the current on the negative side of the circuit - number wise surely it doesn't make much diffs which side but is there some other reason?



I first came across this at a Solar Show in the Philippines - and the sales guy made a point of mentioning this, but I didn't press him as to why.

Any ideas?

Once I am done I will open source my design and s/w - I have done galvanic isolation, RS-485 interface, environmental monitoring etc

Thanks.
 

Offline Seekonk

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Re: Combiner Box voltage and current monitoring
« Reply #1 on: August 11, 2017, 08:07:03 pm »
I assume they are using a shunt and it is just cheaper to implement on the low side like all those cheap Power monitors from China that are sometimes hard to implement.
 

Offline Inverted18650

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Re: Combiner Box voltage and current monitoring
« Reply #2 on: August 18, 2017, 09:54:39 pm »
@kosmonooit,

Do you have a link to your build? I'll follow this thread & hope you will update us. Thanks

Offline David Hess

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Re: Combiner Box voltage and current monitoring
« Reply #3 on: August 19, 2017, 02:54:56 am »
I am trying to figure out why they monitor the current on the negative side of the circuit - number wise surely it doesn't make much diffs which side but is there some other reason?

The reason is either convenience or habit.

In practice, I find that high and low side current sensing are equivalent in difficulty once you learn the more obscure (old) circuits for doing them so the convenience factor becomes where to insert the current shunt.
 


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