solar set-up fuse sizes

[ratfink56]

Solar virgin here needing help please. 

 Just received my Renogy 200w starter system with Rover 20w mppt controller. I have a 100ah 12v agm battery. According to the instructions fuses are required between the panels/controller and controller/battery.

 Panel to controller cables are 10awg as are the tray cables. The NEC chart lists max current at 40a for the wire. Instructions say 20a fuse for controller to battery and for panel to controller either a 9a fuse for series or 18a for parallel. Is that for how the panels are wired? I'm confused. If it is the panels I think they are parallel.

 Also what size fuse from battery to fuse block if needed. Power use will be limited to a 15qt truck fridge, cpap, and charge ports for flip phone and Kindle.

 Do you prefer fuses to breakers and what style do you recommend?

 Thanks in advance.

[MN C Van]

Renogy 200w starter system with Rover 20w mppt controller.

According to the instructions fuses are required between the panels/controller and controller/battery.

Instructions say 20a fuse for controller to battery
panel to controller either a 9a fuse for series or 18a for parallel.
Is that for how the panels are wired? I'm confused. If it is the panels I think they are parallel.

 Also what size fuse from battery to fuse block if needed. Power use will be limited to a 15qt truck fridge, cpap, and charge ports for flip phone and Kindle.

 Do you prefer fuses to breakers and what style do you recommend?

Sounds like you answered most of your own questions.
You can connect the panels in either series or parallel.

You can fuse the cigar lighter outlets like in a house- Not by what, specifically, the homeowner is going to run on that particular outlet, but by the circuit's capacity. So you could plug in an LED light that doesn't use much power, or a small air conditioner that will guzzle power on the same outlet in a house.

So, my van has 20 Amp fuses for cigar lighter/power outlets, you could just use a 20 Amp fuse as long as the connectors, wiring and outlet are rated for that.

That way, say you get an inverter to plug in an electric razor, you wouldn't have to up the fuse.
Or change it after two years from now you forgot you put in a 7amp fuse- and it blew using the inverter.

That make sense?

[Blacktank]

here's a little write up on fusing https://vandwellerforum.com/showthread.php?tid=656

[Scott7022]

For low voltage/Amp connections, I like the little breakers for car audio. Only ever smoked one. Tripped them a bunch over the years never had one go south on me. The one I smoked was an oops I read that rating wrong. It still tripped the circuit as it gave up the "magic smoke" and died.

[ratfink56]

Thank you all for your help. Onward!

[sternwake]

I have a 30 amp pushbutton/Lever audio style circuit breaker on My SC to battery circuit. My IR gun indicates it gets significantly warmer than the surrounding area, indicating electrical resistance. I can detect some voltage loss across it too.

All fusing methods add resistance, but I think some more so than others, even at the same amperage rating.

If I were to decide to spend the money and effort improve my Solar controller to battery circuit, i would use one of these:

https://www.bluesea.com/products/old/5006

Not sure the extra wattage into battery, would be worth the expense at this point, nor how much more wattage would get to battery,
But if I could start anew, this is the product I would use for this purpose.

Though the pushbutton disconnect of the CB, has been convenient, just do not press it in full sun.

There are MANY similar styled pushbutton circuit breakers, many at significantly cheaper prices than Bussman or Blue seas brands.

I have one such one, on My direct laternator to Battery feed. rated at 140 ampsw.

After 5 minutes of passing 100 amps it tripped, and I am very lucky it did not take out the diodes in my alternator.

Trying to save money on fuses or circuit breakers or the wire terminals, has been a huge regret of mine, and I urge readers to save money elsewhere, when initially setting up an electrical system.

It Will be cheaper in the long run, and likely yield better performance right off the bat.

Save money elsewhere.

[rvpopeye]

Proper wiring with quality connectors made a huge difference in everything I did in pro audio.
That holds true with any device.

[Scott7022]

I usually recommend Blue Sea but I get a PM saying how not everyone has that kind of money. So I went with the next best option. With a better margin of error than other systems. Trying to be helpful while understanding the audience. Personally, I always want to know HOW to do it right and understand the science or physics then make an educated decision to do something closer to stupid. I have been too long out of car audio to make a product recommendation but back in those days, many rated breakers would snap at lower Amps than rated and get hot. That means resistance. If you are squealing the tires you're wasting forward momentum. Same idea here if it is getting hot it is stealing the big red ball energy harvested to warm itself.
The great deals on Amazon allow people to buy a bunch of EFX 125amp breakers that are B or C stock and flog them to unsuspecting people that want or need to do it cheaply. So listen to the professionals that have spoken here. If you just can't swing doing it correctly then protect it the best you can knowing it has to be changed and as such bought twice. Don't skip protection and just hope for the best.

[ratfink56]

Scott7022 I'm not sure why someone would send a pm like that. Hope it wasn't a mod. Seems silly to chastise a person for sharing their knowledge. Too many butthurt snowflakes these days.

When I ask for advice I want to know what to look for in a product. I also want to know what is the best. I may not have the money for it but I still want to know. Especially on the subject of electrical components and installation. Last thing I want is to burn my van to the ground. Even with the modest system I have chosen I want quality ancillary bits and pieces.


Thanks again for your input.

[GotSmart]

I had a person that wanted my help. The system he was installing was designed yet a Microsoft engineer. The lithium batteries were on their sides inside a fruit crate packed with foam squares. Large flexible panels , ~~~. 

Some people must do things three times to get it to work. 

They do it there way ONLY.