When And Where To Use Fuses For DIY Solar

[@everydaysolar]

Calculate Solar Cost For Your Home - geni.us/solar_reviews EcoFlow Delta Pro 3 - geni.us/F9wfz 10 Amp Fuses - geni.us/CZts 15 Amp Fuses - geni.us/klFeL 20 Amp Fuses - geni.us/tIAw 25 Amp Fuses - geni.us/fuLn5 30 Amp Fuses - geni.us/IyW6ig DISCLAIMER: This video and description contain affiliate links, which means that if you click on one of the product links, I’ll receive a small commission.

[@cherylbrown7622]

Thankyou, i have watched LOTS of solar videos and your expaination for when and how to use fuses has been the easiest to understand!

[@MrFirstone23]

Man, Yea! Not enough info and conversation about this on YT. Out of confusion and concern, I bought a miniature 30-amp disconnect switch/circuit breaker to put between the panels and the Delta Pro. I'm currently just using 6 -100-watt panels but upgrading to approximately 1600 watt. Few years back a BougeRV tech said I wouldn't need fuses with a 1600-watt system. Anyhow, the topic of using fuses doesn't seem to get the attention it deserves, or maybe I'm just being too careful. Those DP's sure are pricey though... Great video, Thanks!

[@everydaysolar]

Thanks for the feedback and yep the DP, DPU, and DP3 are not cheap. For certain applications they make a lot of sense but also good to look at the DIY path as well if you system is stationary.

[@zorro5651]

Nice explanation. One problem I had is that with my eco-worthy 100w panels, the outputs are not red and black wires, so I had to look at some other fusing videos to tell that the connector that looks like a male is the plus, or the "red" wire. Also, from what I can tell, other brands also had the plus connector on the right side of the little box on the back of the panels. I wonder what would be the effect if one put the inline fuses in the negative side instead. After all, the inline fuses have a male on one end and a female on the other, so it is not foolproof since one could put the fuses in the negative Y connector just as easily. I think I did the fuse size wrong, however. My panels say 5.5 sc amps and 10 amp fuse. I thought one would have to add the 5.5 and get 11 and so I am currently using 15 amp fuses. It should be easy to just replace them in the inline fuse holders, I would hope. Adding to my confusion, I have 4 panels, with 2 connected in series (40v) and then the 2 pairs in parallel. I have an ecoflow delta 3 plus that maxes out the voltage at 60 (with 500w) so I can't just series connect the 4 of them.

[@MrCrixizix]

I'm a bit unclear on what kind of circumstance these fuses would help with. You've said a short that causes more current to go through a single branch. Could you give some clarification or an example of what this type is failure might look like?

[@eddietee6305]

Each panel has a short circuit rating and they are connected in parallel. The diodes in the connector of each panel can short out - current tends to find the path of least resistance.

[@diySolarPowerFunWithRay]

Great video. This is the exact solar configuration I recommended in my delta pro 3 review video. But I forgot to mention the fuses though. Good reminder.

[@everydaysolar]

Yeah, I like over paneling the High voltage side a bit to stretch out the peak sun hours and get you a little more on overcast days. Overall I am impressed with the DP3 thus far and was able to charge the Cybertruck up with 9 kWh from solar yesterday from the DP3 which is not too shabby.

[@drs3055]

Humm! I have 200w Renogy Portable solar panels to charge our rv battery and solar power stations at different times. When purchased, the portable panels were wired to only charge solar power stations - didn't have charge controller. I purchased a Renogy Voyager 20amp Charge controller, and wired the panels to connect into our RV SAE connector. I kept the charge controller close to rv battery, and placed a small atc fuse block (20amp) on red wire between the charge controller and battery plugged into RV's SAE plug. From your video, it sounds like I didn't need to fuse anything? If I didn't to fuse, do I need to eliminate the fuse or leave for added protection? 20amp fuse looks to be too high, too? Thanks much.

[@chrisdsanders]

Question, how do you calculate the max current for each string? The DP3 Low-PV is rated for 20A and the High-PV is rated for 15A. I was under the impression that you use the "Isc" rating. If that were the case, you would be over current on both, right? High= 18.82A and Low = 36.63A. If that's not the case, then how would one calculate the max current from each of your strings? Should I be using Imp instead of Isc? If we use Imp instead of Isc, then High = 17.8A and Low = 34.86A. Either way, aren't you over the current rating of each solar input?

[@swithers00]

Any idea how to determine fuse size when the panel doesn't list one? I have 2 BougeRV 100W panels. This is the info the label provides: Max Power (Pmax): 100 +/- 3% W Max Power Voltage (Vmp): 18.15 +/- 3% V Max Power Current (Imp): 5.51 +/- 3% A Open Circuit Voltage (Voc): 21.4 +/- 3% V Short Circuit Current (Isc): 6.11 +/- 3% A Max System Voltage: 1000V DC Application Class: Class A Operating Temp Limits: -40F ~ 185F I tried contacting their Customer Service but got the run-around, and finally a partial answer. They say if I connect the two in series, I need a 10A fuse. I'm guessing from your video that I will need two 10A fuses if I connect them in parallel. I really wanted to get more panels but hesitate since I don't have this info.

[@Bigsparky710]

The short circuit current is 6.11 and you times that by 1.54= 9.4 so you would use a 10amp circuit. This is only if hook them up in parallel. If you are hooking them up in series then you would not need a fuse because your not increase amperage but just the voltage. You will still need to breaker this at the house or before the controller/ inverter.

[@gonzaloburgos8642]

Great video the diagram helped me understand better 👍👍

[@everydaysolar]

Awesome, thanks for the feedback!

[@jimmy4518]

any downsides to undersizing the fuse if there is a ton of room between isc and max fuse rating? i.e. isc is 11.26A and max fuse rating is 20. was thinking about doing 15a fuses

[@everydaysolar]

I don't think so, for instance on my Solar L side even though the fuse rating is 25 Amps I would be comfortable using 15 Amps or 20 Amps.

[@dragonfalcon8474]

Noob question. Does it HURT to have inline fuses in a series setup on the solar panel side of a switch/circuit-breaker/etc, in case there is a short circuit (from water or fault wiring/electronics) or something?

[@muhjeepsrock3161]

Will be utilizing three 410w solar panels in series for a total of 1230w, 112v, and 10 Amps that will plug into an Ecoflow Delta Pro (2). I will be grounding the solar panels, but wondering if I need something for lightning/surge protection? I was thinking maybe a 15 amp inline PV fuse prior to connecting to then Delta Pro? Am I just overthinking this? Thank you!

[@Mgamerz]

I have 8 panels - 4S2P (I think that's the notation?). They go into a combiner box with each series having a 10A fuse. I assume that covers this? The fuses are before the combination, not after.

[@everydaysolar]

Yeah, that should work assuming the Isc is below 10 Amps.

[@dreamonit5555]

I have two strings in series one string has eight panel 370 wide yeah the string has seven panels three out of 70 W do I need to fuse either string

[@stevew3731]

Great information. Thank you. I'm currently running the DPU with 4 batteries for a total of 24kw. I have (8), 400w panels, in series, charging the DPU. I plan on only solar charging at this time and only using it to charge up my 30kw, Nissan Leaf. Hope you can help me or anyone else with my questions. Do I, should I, ground the DPU unit? I see a ground screw on the unit. I was thinking about adding more panels to bring the total up to the maximum allowed, which I believe is 4000w for the high solar input. Can I mix one or two more panels that do not have the same output rating? As an example...can I add two more panels rated at 375w each or one panel rated at 800w? These are just hypotheticals. Not even sure they make panels rated at 800w. Thank you in advance for any information.

[@ngk330]

I’m going to be running 5s3p 100 watts ecoworthy bifacial panels. I bought a “DIHOOL Solar Panel Disconnect Switch 30 Amp Breaker Box” from Amazon. I believe the breaker would work the same as a fuse, or should I look into a legit fuse?

[@thechamp66]

Heliene 66M HJT All Black Module - 360 watts on DP3 have a VOC of 48.62 so 3S puts these at 145.86 volts at STC. These panels in 3S will exceed VOC of 150 volts when panel temperature gets below 14 Celsius or 57.1 F

[@everydaysolar]

Thanks for running the numbers. Appreciate the help!

[@eddietee6305]

The 3s panels will not see the 150v. They are in series and hence they can only see the output voltage of each individual panel. The voltage adds but that doesn't mean each panel is seeing that full 150v. Just think of batteries in series. A 12v battery can only see 12v whether connected in series or parallel.

[@thechamp66]

@@eddietee6305 The Delta Pro will see the 150 volts. VOC occurs without current.

[@jasonrose9813]

On the top diagram. I am thinking no fuses would trip as the most the other string could pump in is under 15 amps? You are assuming that the top would have 10 going through the top fuse but why would it if the sink is a panel in that string. Am I wrong and if so can you explain? Thank you!

[@everydaysolar]

In normal operation you are correct. The fuses are just protecting against a short circuit where you might have both branch currents going through one side.

[@ThomasNowicki-m5s]

if the nmaximum current is 9,41 Ampere and the short circuit is same coz a 9,41 Amp panle can not put out more then it ca so a 15 Ampere fuse is pintless . this fuse not protect anything coz this current againt this fuse protect never will be there.

[@teuton6167]

Thanks for doing this video. This is the exact question I had about fuses.

[@everydaysolar]

You bet, happy to help!

[@jarenru]

Hey there, thanks for the video. Question - for the top configuration, since your Isc is 9.41, what is the rationale for using a 15A fuse instead of 10A? Maybe my next question answers this, but when does the 1.25 (indoor) or 1.56 (outdoor) safety multiplier come into play?

[@ThomasNowicki-m5s]

it is pointless is the answer. if a panel or seriall string can put out 9,4 Ampere max so that is the maxium in any aspect so if one or more panels fail still 9,4 Ampere is the maxiumum possible current so to put in a 15 Ampere fuse into this string is 100% pointless in all aspeccts. and if you use parallel configs there is a possible way to use a fuse for example 4 panela in parallel and each one makes 10 Ampere so a total of 40 Ampere. lets say one panel fail in this setup in this exotic situation the failed panel becomes a ccnsumer and this consumer can draw it rating so maximum 10 Amere but in our example we have 3 working panels that still produce 30 Ampere and coz the current goes the shortest way the current go in this situation to the failed panel and pump into it 30 Ampere what will result in heat up and posssible burn coz this failed one can only handle 10 ampes producing or cinsuming but not 30 Ampere. so in this situation a lets say 15 Ampere fuse makes sense. but the other problem is shaded panels doing same like failed panels to switch from producer to consumer so the last 15 year Pros not use fuses but blocking diodes "sachottky" that is the solution for any sort of fail, not only a 100% fail of a panel in parallel setup but also failed cells on panels what is not easy to find fast this problem or partial shading , it prefents against any sort or possible problem. thats why fusses in solar setups are pure nonsens on the panel side. the only needet fuse is on the battery thermial against a wirre burn "short/ over current from batttery" and thats is the only real needet fuse , no other fuses. and this fuse much mach with your battery wires, so if your wire can handle 30 Amps put in a 25 Amp fuse in so you have a large safty filed put in without posibilyty of heating up wires over time or wire burn. fuse for battery always below the maximum current of a wire, coz a wire heats up on maximum over time, and if some strains in the wire broken with the maximum the wire can melt burn.... so use always wires than are stronger then you need and then fuse is below its maximum Ampere for real safty. an example from real world: my solaer delivers 10 Amps so wire must be higher ratet for example i take now 30 Amp wires from the charge controller to the battery. no no war up on any way coz only 10 Amps is maximum movment of current and to protect this wire to not can burn if for example battery get a short i put in a 25 Ampere fuse. so the maximum current will always be below the wire posibilitys and anythink is 100% safe. same for example to inverter. the inverter need maximum 60 Amps so i use a 80 Amps + wire the put in a 60 amp fuse. so inverter never get more power then he can same like wire.... this the only real fuses what makes sense. solar panel never need a fuse coz they are limited by themself !!!!

[@evahsia]

I suggest in the future to show the whole circuit without the fuses (red lines connected to MPPT), then add the fuses. Those hanging red lines at the start are confusing. (The connection at the EcoFlow does not change, the fuses go upstream of the existing Y connections.)

[@everydaysolar]

Thanks for the feedback 👍

[@chimneyrock123]

GREAT explanation! Thx!

[@timcat1004]

I opted for no fuse. I've had two different fuse holders fail. They suck,

[@charleshill7184]

You say 3 bi-facial panels on your ground array, but doesn't the video show 4 panels?

[@everydaysolar]

There are 4 on that mount but I only have 3 of them wired in the circuit.

[@gspam154]

Great topic and thank you for the presentation. I don't fully understand the placement of the fuses or where the magic black smoke is going to come out, so I would welcome additional videos on this topic.

[@eddietee6305]

If any one of the panels have a shorted diode or any particular shorted buss bar on the panel which might result in the current taking that path of least resistance then it is advised to fuse accordingly so the problem panel's fuse would act first.

[@odoohub5010]

@@eddietee6305 should we not use Isc , since the Isc can never be exceeded during a short circuit?

[@ThomasNowicki-m5s]

first example: 2 strings where every string brings 9 Amps put in 15 Ampere fuse for what'? a strings delivers with 9 Amps the maxiumum possible current possible so to fuse against 15 Amps that will never be possible... pontless in any aspect. if one or 2 panel in ysour strings fail they will be bypaased and the working panel deliver still 9 Amps, so what is the point of a 15 Ampere fuse??? if you will protect a string against another string then you must fuse against the maximum possible current an this is 9 Amps.... and to fuse against the working current = not work, to put a bigger fuse the max possible current is pointless. the same trash in example 2 3 panels with 12 Ampere in parallel put on any panel a 25 Ampere fuse. frash over trash. if in a parallel string on panel fail it becomes a consumer, so in your example 2 panels will put out 2x 11,5 Ampere=23 Ampere and pump it into the failed panel so the fuse will not do anythink and then the failed panel will heat up to the point of fire...and burn, and the fuse will do nothing coz still 23 AMpere is alll the failed panel get..... so if you will prevent that is the key tpo understand how elektrizity works and not read any trash and show here your halfisch theories. and yes your fuse will work if you take for exammple 4 of this panels in parallel coz the current will be then 11,5x3= 34,5 Ampere so your 25 Ampere fuse will now get blown. with your example you only show that you have no idea of Power. the much more common way in many aspecst is to put into parallel setups blocking diodes , on this way you prevent really all possible problems. only on this way you prevent a back flow off current into a failed panel or a partial damaged panel that drains lets say 20% off the current what producend from panel 1+3 and will be drawed from panel 2 about anyx fail , or shading or damaged cells on the panel.... all ppssibel fail can only be protected with this solution. a fuse only can stop a fix current if you use the right fuse. so in your example 2 fuses with ~22 Amps or lower only can block the full current of 2 panels, but no other fails that happening all the time. 3 panels parallel 2 panels full suin 1 panel fully shaded turns the shaded panel into a cunsumer and current from the 2 fully sun panels pump current into it. how your fuse helps here on a dayly problem??? fusing panels is in any aspekt poimtless. the last 15 years schottky diodes are the way to go like the next 15 years..... in reallyty there exists no scenario there are any need of a fuse in any solar setup. from panels to the consumer/charge controller no fuses need or make any sense. the only fuse that can be placed is on the battery + thermial and that is the only one fuse !!!!!