homelesshartshorns

9 minutes ago, Randyretired said:

A 30amp inline fuse will not protect the controller.  The 40 amp rating is based on the output.  Part of what a MPPT controller does is change the panel voltage to the battery voltage and change that excess voltage to amps.  For instance the VOC on your panels is around 24.3v and 2 wired in series produces 48.6v.  The MPPT converts the amps at 12v by a factor of 4.  So 30amps at 48v becomes 120 amps at 12v.  The limiting factor here isn't the fuse.  It is the panels that are not capable of producing that much.  More importantly though is fuses should be sized to protect the wire.  This is basic engineering.  Each component should have internal protection and in this case the controller will not accept more power than the 40amp output.   In fact it is common and even suggested by many MPPT manufacturers to purposely over panel an a MPPT.  Since solar only rarely outputs full power only a small amount of the power will be clipped.  Allowing this clipping is a way to save money on controller's with very minimal loss.  Your panels will never put out more power than this 40 amp controller can use.  MPPT's typically produce heat while working.  If you are more comfortable with the 30amp fuses they won't hurt anything but they are not needed

I wondered why a 10 amp in line fuse failed? The 10A fuse blowing is why I went with 30A!! We are talkin 30' of # 10 wire between the array and the controler.

8 hours ago, Chad Heiser said:

Those in line fuses are best installed with each solar panel at the positive pigtail coming off the solar panel.  This way the fuse is protecting the single panel it is connected to rather than a line of solar panels (that they often aren’t sized properly for).  This means using one fuse for each panel.  A lot of budget kits try to get away with one fuse for the entire array, but then don’t specify how the array is to be wired (to keep the amperage within spec for the fuse) or simply supply the incorrect sized fuse for the application.

I have two 30A inline fuses comming and with what I understand I am trying to protect my 40A controller from my cheap array, that occasionally overheats. So thinking to put a fuse in each of the two series panels. Is this a good plan.

4 hours ago, Chad Heiser said:

For the two panels in series, the voltage doubles and the amperage stays the same.  For example two 25 volt panels at 4 amps in series would produce a 50 volt at 4 amp output.  When two additional series connected panels are added in parallel, the voltage will remain the same and the amperage will double.  With the four panels in this example in series parallel (2S2P), the end voltage will be 50 volts and the end amperage will be 8 amps.

I am not a fan of the in line fuses like you found on your set up for the reasons your system is having issues.  They tend to blow at very inconvenient times.  Most that I have found are typically installed incorrectly as well.  They tend to be installed  in the wrong place in the string and end up getting more amperage than they are rated for as a result and blow.  I had to remove one from someone’s system the other day for this exact reason.  It was installed in the wrong place in the array and was getting more amps than it was rated for.

I prefer a DC rated breaker down by the solar controller.  Not so much for the circuit protection ( for the reasons Lou Schneider explained), but to be used as a shut off when I want to isolate the panels from the system for testing or service or whatever.  Plus a circuit breaker is resettable rather than having to replace a fuse.

You mentioned putting the fuse in the wrong place in the array! Is the right place near the controller or is that location just more convenient than the right place? Or is the best option no fuse. I have ordered a 30A fuse.

9 minutes ago, Randyretired said:

I know that sounds like a simple question but if I just answer it it may not make sense.  Let me try to explain.  Fuses are to protect the wire and are based on amps.  When solar panels are wired in series the voltage is multiplied by the number of panels but the amperage stays the same.  When panels are wired in parallel the amps multiply but the voltage stays the same. Your panels produce 5.2 amps and 24.3 volts.  So in series the voltage is high but the amps are still 5.2.  Wire size is based on amps and fuses control the amps.  In series the amps are low and the wire will easily carry the current.  So in series the wire will most easily handle the current.  So yes in series I would not recommend a fuse.  However, since fuses control only amps, fuses will not control voltage.  So adding a fuse will not protect the controller from high voltage which is why based on advertised spec's I can not recommend series wiring.  In any case a properly sized fuse of 30 amps should not cause any problems no matter how the 4 panels are wired.  If Renology endorses series wiring you can probably get away with it and a fuse will make no difference either way.

I think I'm getting it.  Series will produce more power than the 40 A Controler can handle, in cool weather! But if I stay in Partial and get the 30 A fuse, wires are big enough for the power produced and the fuse will keep the controller safe. 

I appreciate you comments. Your thoughts are not to go with out a fuse if I rewire my array ln series?

I finally stumbled on my issue I think.

 New 400 Watt 12 Volt Solar Premium Kit | Renogy Solar

On this page I set my system up in partial configuration. And put the 10 amp fuse in line where is says 30 AMP Fuse not included!!! What a Deal!!!

So according to these two configurations in series I only need the 10 amp fuse and in the partial seem to need a 30 amp fuse.  So my next question is do I still need a fuse at all? It looks like if I was to go series I might get away with no fuse? 

Thanks for you input. Has given me food for thought and suggestions are always helpful. Ill let you know if I burn the house down.

55 minutes ago, Randyretired said:

Yes.  That is what I would do but you should check the spec's on the panels.  Based on these numbers 10amp fuse is to small.  It is good to see your array actually providing full power.  It must be setup correctly.  I don't consider myself an expert but I do have experience in solar. If you are not comfortable with my suggestion please get another opinion.

My only uneducated question is why would a kit come with a fuse that seems to small? Would me adding 10 foot of cable be an issue? Other than that I have everything set up accoriding to instructons for the partial array.

So you seemingly have way more experience than I do, witch is Zero! I did take the blown 10 amp fuse out of the line and seen the array does put numbers on my app indicating the array is hot. So your sugestión is stick with parcial un protected and not do all four in series?

This is a 400 watt Renogy kit with a 40 amp mtt controller.  10 gage wire witch I added 10 foot to reach the array. 

Thanks for the feedback.

Run this by you all! As I read it using partial series and parallel has more short circuit power then if i was to run the four panels in series. In series I can use a smaller 10 amp / 1000-watt inline fuse or even no fuse! Am I thinking this right?

On 2/3/2024 at 1:20 AM, Chad Heiser said:

Disconnect the panels from the wire leading to the solar controller.  Use a multimeter and check voltage on each panel by inserting the meter probes into the pos and neg pigtails coming off the panels.  This will tell you if the individual panels are producing electricity.  If they are, reconnect the panels to the wiring and go to the next junction in the wiring and do the same thing.  Keep going until you find where there is no power.

Ok there is no power getting past the 10-amp 1000-watt inline fuse on the roof. If I take it out of line, all comes on again. So, is the fuse too small or should I consider that the panels are wired wrong? I have it set up in two panels in series and then those two are in parallel. 

Will do thanks.

Ok bring you all up to date on my solar project. I got the kit installed and all went well for about a week. But on the second week my panels have stopped producing power and so I am stuck. I can find no loose connections, and all seems to be as it was before I hooked up the panels to the controller but now no power. 

I must say I was quite impressed at the ease of installation, and all just seemed too full into place. But now I don't know what to look for. The instructions are all very good as to the install and steps to take. But nothing is mentioned as to what to look for if it stops working. So, I will let you know what I find out. Safe travels

5 hours ago, Chad Heiser said:

Just make the connection.  No need to wait until dark.

Thanks

Thanks

On 1/12/2024 at 12:47 PM, Dutch_12078 said:

Newer model, but an exact bolt in and wiring match.

https://generators.visonerv.com/cgi-bin/md/M80078/s1.pl?

Is this place in Kentucky?

Quote

Moscow Iowa in March. I am not much for shipping. 

Well, we spent last summer on the west coast and just came by you. But we are in Brownsville, TX. and will be headed north this spring.

I have hooked up the battery to the controller and the Solar panels are tied together. Do I want to plug the panels to the controller and let her fly? Or should I wait till the sun goes down to hook the last link up?

Where is the ranch?

I'll be in Brownsville Texas tomorrow. For a week or two. This seems to say I have a 25' pole.

https://www.campingworld.com/weboost-destination-rv-127134.html?utm_source=google&utm_medium=ppc&utm_campaign={Campaign}&cq_cmp=19941437670&cq_con=&cq_term=&cq_plac=&cq_net=x&cq_plt=gp&gad_source=1&gclid=Cj0KCQiAhomtBhDgARIsABcaYymA58GBmHWg5FSFFwTHcDCwDgXNANnaunCaXDZk7rpttjo94UjiDcwaAoxBEALw_wcB&gclsrc=aw.ds

2 hours ago, lappir said:

Interested, but shipping may be costly. Where is it and how tall is it in it's shortest configuration? Would also be nice to know how tall it extends. 

 

Rod

I'm pretty moble. I'm at Riviera Beach today. How about you? Dou you move around?

Good lead, Thank you.