Adding a fuse in series panels.

[Jim Burrow]

I picked up 6 Talesun Solar panels yesterday (VOC-38.7 ISC-9.17 41lb 65”x39”x1.75”) for $120 cash (hence, no taxes, no shipping). I live 20 miles from the guy, so I picked them up in person. – wore my mask of course!

If you live in the S.F. bay area (he lives in Concord) he still has around 10 left that he wants to sell. For what I need to power my home, 6 panels are quit enough, in theory, as I have never experimented with home solar systems.

Anyway, my question is, reading the Spec sheet on these panels, it says that I should use a 15-amp fuse in all series panels. When you guys built your systems, did you install fuses in all your series panels? – I can’t tell, but I don’t think the fuses are built into that black box that the cables are connected too on these panels.

 

[HRTKD]

Fuses are not built in.

General consensus seems to be that fusing between parallel strings is a good idea. Not necessary within a series string.

 

[snoobler]

I have Talesun 330W panels. Love 'em. They have no fuses anywhere.

I use a Midnite solar 15A breaker per series string. They're designed for higher voltage DC.

 

[gnubie]

Putting aside regulatory requirements, think about your system. If you have a SCC that can accept 20A on its input, your cabling is rated to carry full current from your array which it should be and your array can only produce 7A, what fuse can offer any protection but also not nuisance blow as your SCC performs normal MPPT operations,

 

[snoobler]

Putting aside regulatory requirements, think about your system. If you have a SCC that can accept 20A on its input, your cabling is rated to carry full current from your array which it should be and your array can only produce 7A, what fuse can offer any protection but also not nuisance blow as your SCC performs normal MPPT operations,

Not understanding.

So because my Victron is rated for 70A PV input, all of the wires from my panels should be 70A capable even the installed panels can only produce 27A?

 

[gnubie]

Yes, you are not understanding. The wiring should be rated to carry full current from the array, ie in your example 27A.

 

[Jim Burrow]

I'm needing MC4 connectors to wire everything together. Is one brand better than any other? Here is what's on Amazon.
Note my junction box MC4 compatible and is marked IP68. Does the IP68 have anything to do with respect to MC4 connectors

• BougeRV
• Renogy
• JHBOX
• PowMr
• yarachel
• LINKPAL
• Hilitchi
• JYFT
• WindyNation
• BeideLt

 

[snoobler]

Yes, you are not understanding. The wiring should be rated to carry full current from the array, ie in your example 27A.

At least we agree on something. Must be a language barrier thing...

 

[Liam M]

I picked up 6 Talesun Solar panels yesterday (VOC-38.7 ISC-9.17 41lb 65”x39”x1.75”) for $120 cash (hence, no taxes, no shipping). I live 20 miles from the guy, so I picked them up in person. – wore my mask of course!

If you live in the S.F. bay area (he lives in Concord) he still has around 10 left that he wants to sell. For what I need to power my home, 6 panels are quit enough, in theory, as I have never experimented with home solar systems.

Anyway, my question is, reading the Spec sheet on these panels, it says that I should use a 15-amp fuse in all series panels. When you guys built your systems, did you install fuses in all your series panels? – I can’t tell, but I don’t think the fuses are built into that black box that the cables are connected too on these panels.

How many watts/panel and the $120 is each?
Edit: nvm found the ad, thanks.

 

[Jim Burrow]

How many watts/panel and the $120 is each?
Edit: nvm found the ad, thanks.

sorry, I didn't notice not posting the wattage - these panels are 295 watts

 

[HRTKD]

I'm needing MC4 connectors to wire everything together. Is one brand better than any other? Here is what's on Amazon.
Note my junction box MC4 compatible and is marked IP68. Does the IP68 have anything to do with respect to MC4 connectors

• BougeRV
• Renogy
• JHBOX
• PowMr
• yarachel
• LINKPAL
• Hilitchi
• JYFT
• WindyNation
• BeideLt

You missed TEMCO Industrial. MC4, 30 amp, Package of 6 pairs.

 

[Jim Burrow]

Temco industrial is not one of the Amazon companies they sell for as listed above. But I'm wondering if the IP68 has anything to do with the MC4 compatible part!

 

[HRTKD]

Temco industrial is not one of the Amazon companies they sell for as listed above. But I'm wondering if the IP68 has anything to do with the MC4 compatible part!

I have no idea what you mean. Who is "they"? TEMCo Industrial products are available on Amazon.com. You can also order their products directly from TEMCoIndustrial.com

 

[erik.calco]

sorry, I didn't notice not posting the wattage - these panels are 295 watts

Honestly, Jim, you have just begun your adventure -- and investment. Congrats on a great deal on the panels!!!

The good news is learning is fun! I recommend watching some videos by Will Prowse, the owner of this forum:

DIY Solar Power with Will Prowse

Want to build an awesome off-grid solar power system? My videos will teach you everything you need, no experience necessary :)

www.youtube.com

He's awesome, and will break things down for you in an easy to understand way. You can begin playing with 1 panel, batteries and a cheap SCC just to learn while you plan and design your complete system.

I'm guessing you've been around enough to know we have a good FAQ section:

Frequently Asked Questions

diysolarforum.com

and have probably seen a few design diagrams by various people. By all means, continue to ask questions. But, your ultimate goal is to design a complete system, including SCC, batteries, OC protection, loads, etc,...

Most use breakers, and thus don't have fuses in their PV lines. Your OC needs depends on how you design it, which will depend on how many in series or parallel, which will depend on your SCC ranges and how much you want to invest in wires.

I do not have fuses. I use MidNite 150VDC breakers in a combiner box. My panels are 320W each and I run 2 in series on each string.