Woggs1
New Member
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https://www.amazon.com/ACOPOWER-Lin..._1_3?keywords=mc4+diode&qid=1573050544&sr=8-3. I ran across this MC4 diode on Amazon. Under what circumstances is this appropriate?
MC4 diode
- Thread starter Woggs1
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Typically used as a blocking diode in pv arrays.
Blocking diodes can be useful if two parallel strings (2 different arrays connected in parallel) are facing the sun at different angles, a blocking diode will ensure that the voltage drop is not as severe.
Useful if using a single PV controller with two arrays, and one array has lots of sunshine in the morning, and the other array has lots of sunshine in the afternoon. The diode has voltage drop though, so these need to be utilized only when absolutely necessary.
The most efficient configuration is to have 2 separate solar charge controllers. One for each array.
So for most people, not very useful. Unless someone disagrees with me? I would love to know of an application that I do not know about.
Blocking diodes can be useful if two parallel strings (2 different arrays connected in parallel) are facing the sun at different angles, a blocking diode will ensure that the voltage drop is not as severe.
Useful if using a single PV controller with two arrays, and one array has lots of sunshine in the morning, and the other array has lots of sunshine in the afternoon. The diode has voltage drop though, so these need to be utilized only when absolutely necessary.
The most efficient configuration is to have 2 separate solar charge controllers. One for each array.
So for most people, not very useful. Unless someone disagrees with me? I would love to know of an application that I do not know about.
gnubie
Solar Wizard
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- Sep 20, 2019
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I have an array of 5 parallel sets of 2 series panels and have blocking diodes between the sets to the common + wire to prevent any back feeding into a string should it fail / go low voltage etc.
The loss through the diode usually isn't much to worry about compared to the capacity of the string. Assuming an under load drop of 0.7v with 6 amps through the string/panel that's around 4 watts loss vs 100 watts from the panel (24v panel Vmp 18v).
The loss through the diode usually isn't much to worry about compared to the capacity of the string. Assuming an under load drop of 0.7v with 6 amps through the string/panel that's around 4 watts loss vs 100 watts from the panel (24v panel Vmp 18v).
offgriddle
"FOREVER BEGINNING"
Excellent question and explanations, thank you all.
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