Tired of clamping with my meter each string to read voltage and current I thought of these chinese panel meters

[Spanish Flyer]

Apart from the risk of getting electrocuted, I find that every time you need/want to check the input of each string coming from my roof is also cumbersome and rather useless, since by the time you check one (and I have 7 strings)... the reading is already old by the time you have read the next one.
However, I have seen loads of panel meters, sold in Aliexpress and others, for next to nothing, where choosing the right one (for over 600V DC and 20 A), you could actually make a small panel that holds one of these units per string and that way, be able to read at a glance how each of your strings is doing there and then.

As an example I include one option: https://www.aliexpress.com/item/100...p4p_id=202308140244368236461472206181631185_0

Some use an external SHUNT and others already have one integrated in the unit. My biggest doubt however is how to connect them to my strings. It is clear that I would use something like a phone charger (~5V DC) to feed the meter, but how to connect the rest to the string so I get a reading of its voltage and current,,, The reason of my doubts is because if I follow the diagram shown on the meter, it shows the negative side to be shared between the meter power feed and the string negative.. I don't know if I make sense here (how to share the negative line between a 5V wall charger and a 600V negative string ... (it doesn't seem wise to me).
Anyway, let me know what you think.
BR,
Spanish Flyer

I have installed and connected one and it's reading correctly (484 V DC and 1.65 A). This one is using an external shunt, but still, I'm a bit concerned...

 

[ksmithaz1]

Generally DC- is grounded throughout a DC system. For example a PC power supply provides a variety of voltages from +12 to -12 (+5, +3.3) that all reference the same ground. You hook something up backwards and fuses should blow, and/or you will release the magic smoke.

 

[Supervstech]

Apart from the risk of getting electrocuted, I find that every time you need/want to check the input of each string coming from my roof is also cumbersome and rather useless, since by the time you check one (and I have 7 strings)... the reading is already old by the time you have read the next one.
However, I have seen loads of panel meters, sold in Aliexpress and others, for next to nothing, where choosing the right one (for over 600V DC and 20 A), you could actually make a small panel that holds one of these units per string and that way, be able to read at a glance how each of your strings is doing there and then.

As an example I include one option: https://www.aliexpress.com/item/100...p4p_id=202308140244368236461472206181631185_0

Some use an external SHUNT and others already have one integrated in the unit. My biggest doubt however is how to connect them to my strings. It is clear that I would use something like a phone charger (~5V DC) to feed the meter, but how to connect the rest to the string so I get a reading of its voltage and current,,, The reason of my doubts is because if I follow the diagram shown on the meter, it shows the negative side to be shared between the meter power feed and the string negative.. I don't know if I make sense here (how to share the negative line between a 5V wall charger and a 600V negative string ... (it doesn't seem wise to me).
Anyway, let me know what you think.
BR,
Spanish Flyer

I have installed and connected one and it's reading correctly (484 V DC and 1.65 A). This one is using an external shunt, but still, I'm a bit concerned...

A shunt is for tracking energy flow... tallying Wh and such...

Not sure I'd want one on my solar array...

 

[irv818]

A shunt is for tracking energy flow... tallying Wh and such...

Not sure I'd want one on my solar array...

Why not? A shunt has a resistance of about 1 ten-thousanth of an ohm - you're not losing enough energy in the shunt to make any difference.
It's always good to know how much power your solar array is producing.

As for sharing the 600 v negative with a wall-wart - don't. The meter uses so little current, you could power it with a battery and a push-button switch to turn 'em on when you want to get a reading.

 

[robby]

A shunt is for tracking energy flow... tallying Wh and such...

Not sure I'd want one on my solar array...

I totally agree with you.
It just adds another failure point and the data is not all that relevant unless you’re using old dodgy panels that are unreliable. Just about any new or newish panel that is reading fine after installation will in 99% of cases remain fine for a decade or two. Even if you think you’re seeing some slight degradation in a panels output it most likely will not be enough to warrant getting a replacement.
If one or more panels dies completely it will show up on the inverters strings voltage input reading as a noticeable drop.