I have fried 2 charge controllers! Please help!!

[BradCagle]

I purchased 2 sets (total of 8).

Alright, good man!

Never skip fusing even a single panel in a parallel setup like that. One of the panels can short, and all the current from the other panels will feed into it. Major fire hazard.

 

[MushroomMan67]

I purchased 2 sets (total of 8).

Alrighty, but you'll need one more fuse holder. Looks like it only has

 

[MushroomMan67]

Alrighty, but you'll need one more fuse holder. Looks like it only has 4

I believe, doing 5 panels, that each will need 1 fuse and the neg. should have 1 fuse that is connect after the 5 prong connector. I THINK.

 

[BradCagle]

I believe, doing 5 panels, that each will need 1 fuse and the neg. should have 1 fuse that is connect after the 5 prong connector. I THINK.

No, you connect each fuse to the 5 prongs, so each panel has a fuse. No need to fuse after the splitter

 

[MushroomMan67]

No, you connect each fuse to the 5 prongs, so each panel has a fuse. No need to fuse after the splitter

I understand you do that for the positive current BUT for the neg. you only need one fuse after the splitter. No?

 

[BradCagle]

I understand you do that for the positive current BUT for the neg. you only need one fuse after the splitter. No?

You absolutely must fuse each. If you have one with no fuse, and that one happens to short ALL that current will flow to it with nothing to stop it.

 

[BradCagle]

Like this image

 

[BradCagle]

more info on fusing

How/When to Fuse a Solar Panel Array

This blog post is going to teach you how to determine when and if you need to add in-line fuses when designing a camper solar array. Sometimes you need to fuse your solar array, and

www.explorist.life

 

[MushroomMan67]

Like this image

I could have sworn I saw a diagram of this but it had one fuse after the neg. Something about not being grounded (don't remember).
Do you feel it would serve any purpose to do that?

AND THANK YOU FOR THE DIAGRAM AND VIDEO!

 

[BradCagle]

Do you feel it would serve any purpose to do that?

You don't need it, and it'll just be wasting power. These fuses have some resistance, and therefore they can get warm.

 

[MushroomMan67]

You don't need it, and it'll just be wasting power. These fuses have some resistance, and therefore they can get warm.

I just canceled the 10a fuses! I found, by watching the video you sent, that this panel has a Max Series Fuse Rating: 15A.
I am ordering 5 and taking you advise.

 

[MushroomMan67]

You don't need it, and it'll just be wasting power. These fuses have some resistance, and therefore they can get warm.

And I would love to talk to you about running one of those crypto mining hardware in the future. I'm only going to be out at the house every-so-often until I retire. Would love for the panels not to go to waist.

 

[hankcurt]

I could have sworn I saw a diagram of this but it had one fuse after the neg. Something about not being grounded (don't remember).
Do you feel it would serve any purpose to do that?

AND THANK YOU FOR THE DIAGRAM AND VIDEO!

In the U.S. NEC code from 2014, the requirement was that all ungrounded conductors from solar panel strings must be fused. So if you have a system where the negative from the solar panels is not bonded to the grounding system, which is fairly common, you needed a fuse for the positive conductor from each string and a fuse for the negative conductor from each string.

Here is the relevant quote :

2014 Code Language:


690.9(E) Series Overcurrent Protection. In grounded PV source circuits, a single overcurrent protection device, where required, shall be permitted to protect the PV modules and the interconnecting conductors. In ungrounded PV source circuits complying with 690.35, an overcurrent protection device, where required, shall be installed in each ungrounded circuit conductor and shall be permitted to protect the PV modules and the interconnecting cables.

In 2017, the code was updated and eliminated the additional fuse requirement for ungrounded solar panel systems, so that only one fuse is required per string. However, there is the catch that this was done because of the added requirement for ground fault protection in 690.41

690.9(C) Photovoltaic Source and Output Circuits. A single overcurrent protective device, where
required, shall be permitted to protect the PV modules and conductors of each source circuit or
the conductors of each output circuit.

Informational Note: Due to improved ground-fault protection required in PV systems by
690.41(B), a single overcurrent protective device in either the positive or negative conductors
of a PV system in combination with this ground-fault protection provides adequate overcurrent
protection.

I don't have the understanding needed to explain the ground fault requirements, and personally I still see benefit in fusing both legs. However, the one requirement from 2017 NEC that is easier to understand is that there needs to be a disconnect between the solar array output and the charge controller equipment that disconnects both legs. So in the end, this is a diagram of what you are looking at.




At any rate, we want you to be both safe and successful. Have fun!

 

[hankcurt]

Oh, and to give appropriate credit, I found this set of slides helpful in explaining the 2017 code for Solar PV.

https://www.sdge.com/sites/default/files/201202_18434_Presentation1.pdf

 

[MushroomMan67]

In the U.S. NEC code from 2014, the requirement was that all ungrounded conductors from solar panel strings must be fused. So if you have a system where the negative from the solar panels is not bonded to the grounding system, which is fairly common, you needed a fuse for the positive conductor from each string and a fuse for the negative conductor from each string.

Here is the relevant quote :


In 2017, the code was updated and eliminated the additional fuse requirement for ungrounded solar panel systems, so that only one fuse is required per string. However, there is the catch that this was done because of the added requirement for ground fault protection in 690.41




I don't have the understanding needed to explain the ground fault requirements, and personally I still see benefit in fusing both legs. However, the one requirement from 2017 NEC that is easier to understand is that there needs to be a disconnect between the solar array output and the charge controller equipment that disconnects both legs. So in the end, this is a diagram of what you are looking at.

View attachment 109437


At any rate, we want you to be both safe and successful. Have fun!

In a NUTSHELL you are saying that each connector coming out of the solar panel (POS) should have a fuse AND a fuse also needs to be connected to the NEG wire as well? I know you mention this before and I did some research and found that 1 fuse can be connected after the 5 point connector instead of all 5 (I COULD BE WRONG...can't seem to locate it now).

I very well could be misunderstanding and you are just affirming that fuses are absolutely needed for the POS. I am not the best in reading diagram but I do not see any fuses in regards to NEG.

Please confirm when you have the chance.

 

[hankcurt]

In a NUTSHELL you are saying that each connector coming out of the solar panel (POS) should have a fuse AND a fuse also needs to be connected to the NEG wire as well? I know you mention this before and I did some research and found that 1 fuse can be connected after the 5 point connector instead of all 5 (I COULD BE WRONG...can't seem to locate it now).

I very well could be misunderstanding and you are just affirming that fuses are absolutely needed for the POS. I am not the best in reading diagram but I do not see any fuses in regards to NEG.

Please confirm when you have the chance.

I'm sorry if I'm confusing the issue. What you are proposing to do does meet the safety requirements according to the 2017 code with the ground fault things met and a disconnecting means as is in the diagram.

The old fusing requirements from the 2014 code were to protect systems that had ungrounded conductors for both the positive and negative from the panels. Since in an ungrounded system, it is unknown what the potential of either the positive or negative is in relation to nearby metal, say the frame of the solar panel, they wanted both sides fused so that a fuse would blow if the insulation on a wire wore through. So the fuses were in the location immediately before the individual circuits from the PV Array were joined together, on both the positive and the negative.

For me, I'm not informed enough to understand the new grounding requirements, so I think the fusing is still a good idea for me. The other point is that none of us know what your code requirements are, if any. But even if you don't have code requirements, you want to do what is prudent to avoid property damage or injury if the system fails.

 

[MushroomMan67]

You don't need it, and it'll just be wasting power. These fuses have some resistance, and therefore they can get warm.

I'm so sorry to bother you Brad but you are really 'understandable' with solar.
I just wanted to be absolutely positive that this works with 24v solar panel/system. It states: Input Voltage: 12 Volts (DC).
Just need a firm OK...ALL IS GOOD that this is good for me 24v panels.

Thank you!

 

[sunshine_eggo]

It's not particularly helpful when you just post images. Link the items.

There's a spec sheet on that ad:

https://m.media-amazon.com/images/I/C1sEjsquUoS.pdf

The spec sheet lists 150VC PV input.

The "12V input" is likely just a bad description.

 

[BradCagle]

I'm so sorry to bother you Brad but you are really 'understandable' with solar.
I just wanted to be absolutely positive that this works with 24v solar panel/system. It states: Input Voltage: 12 Volts (DC).
Just need a firm OK...ALL IS GOOD that this is good for me 24v panels.

Thank you!

I have not used this controller. But looking at other listings for it says it supports 12/24/36/48v
Pretty sure it will do 24v

 

[MushroomMan67]

I have not used this controller. But looking at other listings for it says it supports 12/24/36/48v
Pretty sure it will do 24v

Yes...I am sure that what it means as well. Just panicked.

Thank you for your time. I'll be going to the tiny house this weekend to hook everything up.
WISH ME LUCK!