Update - do you think this panel compliments this intended PV/Hydro system?

Surfpath · July 2012

Just checking in with an update:

Recap:
Projected energy needs: 4-5 Kwh/day

Synopsis of what I have already:

6 Kw gasoline generator
Hydro turbine & 200 watts (run 10 hrs each evenings) of hydro potential
Tristar-45 dump load controller & resistors

About to pull the trigger on:

Outback Flexpower 1-6 (48V) integrated components on one panel - inverts to 230v/50hz
Eight Trojan L16H-AC 6 volt batteries: 435 amp hr bank

Thinking about:
6 of these 235 watt Solar Power Industries panels. Wired in two parallel strings of 3 panels in each string. Totalling 1410 watts. Here are the individual specs for the panel under consideration:
Attachment not found.
Previous thread here for more info on the project.

Whatcha think. Do the specs on these panels sound OK for the project?:D

waynefromnscanada · July 2012

Re: Update - do you think this panel compliments this intended PV/Hydro system?

Not knowing you're loads, but assuming they are rather light like mine (never a good idea to assume anything), with the projected 2 Kwh daily hydro in the mix, it might be OK, but is definitely borderline for PV power, Without the hydro, definitely not enough PV. If you're loads will be heavier than mine, then for sure you need more PV, unless you intend on regular, almost daily use of the generator. Those are my thoughts when not fully awake after letting the dog out to pee at 4:30 in the morning. Perhaps I should have just kept my fingers off the keyboard.

niel · July 2012

Re: Update - do you think this panel compliments this intended PV/Hydro system?

surfpath,
loads aside it seems fine to me. if you later want/need more in pv then you can add more to it, but you will then need breakers/fuses as well as a means to combine the strings. only way out of that might be putting more pvs in series in each string and that would necessitate a higher voltage mppt cc like the midnite classic as the voc would exceed the max input power to the flexmax with 4 of them in series.

i'm sending you a pm.

Surfpath · July 2012

Re: Update - do you think this panel compliments this intended PV/Hydro system?

niel wrote: »

surfpath,
loads aside it seems fine to me. if you later want/need me in pv then you can add more to it, but you will then need breakers/fuses as well as a means to combine the strings. only way out of that might be putting more pvs in series in each string and that would necessitate a higher voltage mppt cc like the midnite classic as the voc would exceed the max input power to the flexmax with 4 of them in series.

Hi Neil,
Will get to your PM in just a mo. Quick thought. Four of these panels in each string would total 115.08V (too high for the Outback?). If I were to get the right combiner box & shoot for 3 strings of 2 each that totals 57.47V (too low I think for a 48v bank).

If I wished to increase the PV wattage (as Wayne leans towards at 4:30am :cool:), would the next step be to get 9 panels (3 strings of 3 each?) totalling 86.31V?
Cheers,
SP

Cariboocoot · July 2012

Re: Update - do you think this panel compliments this intended PV/Hydro system?

The Outback's Voc input limit is "150". In reality, depending on which revision you have, it will turn off around 140 Volts.
The panel Voc is 36.8 so four in series would be 147.2 which would pretty much guarantee your controller would never work, even without cold weather.

stephendv · July 2012

Re: Update - do you think this panel compliments this intended PV/Hydro system?

Surfpath wrote: »

If I were to get the right combiner box & shoot for 3 strings of 2 each that totals 57.47V (too low I think for a 48v bank).

Correct, 57.47V is too low.

Surfpath wrote: »

If I wished to increase the PV wattage (as Wayne leans towards at 4:30am :cool:), would the next step be to get 9 panels (3 strings of 3 each?) totalling 86.31V?

Yep, 3 in series would be perfect, Vmp would be high enough to charge a 48V bank and Voc will be low enough to fit under the 150V limit, (Voc will then be 110V). And as you point out if you want to expand later on you have to do so in multiples of 3.

Surfpath · July 2012

Re: Update - do you think this panel compliments this intended PV/Hydro system?

stephendv wrote: »

if you want to expand later on you have to do so in multiples of 3.

It seems like multiples of 3 is my destiny. There are so many high watt panels out there with VMP's around 30.

And if I went with 9 at 220w* = 1980W. Doesn't seem to bad. The extra wattage on the roof may be appreciated later on.

-SP

*updated panel specs

niel · July 2012

Re: Update - do you think this panel compliments this intended PV/Hydro system?

my comments in bold.

Surfpath wrote: »

Hi Neil,
Will get to your PM in just a mo. Quick thought. Four of these panels in each string would total 115.08V (too high for the Outback?). If I were to get the right combiner box & shoot for 3 strings of 2 each that totals 57.47V (too low I think for a 48v bank).

correct, but you are looking at vmp and not the voc and it is the voc that determines the max along with temperature.
correct again as it is too low.

If I wished to increase the PV wattage (as Wayne leans towards at 4:30am :cool:), would the next step be to get 9 panels (3 strings of 3 each?) totalling 86.31V?

to stay with the flexmax 3 pvs in series is your only option and that would necessitate additions to be in groups of 3 in series as well. i was merely elaborating that higher voltage controllers can allow additional pvs to be placed in series up to the cc's operating max voltage. too much voltage can damage a cc and the classic has a buffer zone called hyper voc where the controller will just stop operating rather than sustain damage.

Cheers,
SP

note- the only reason i mentioned this is because fewer pvs would need to be purchased for an upgrade if you added 1 in series to each of the 2 strings. it would save the cost of 1 pv and i am not saying that this is what you should do, but only giving options. as i said strings of 3 is your only option for a flexmax cc.

Surfpath · October 2012

I'm pre-wired

Hi folks.

So I'm getting one of these MNPV-4 prewired combiner boxes

Here is the link to my panel specs:
Short version:
Max power: 220 Watts
VOC: 36.29volts
IMP: 7.65 amps
"maximum series fuse rating 15amps"

I plan to have 3 strings of 3 panels in each string: 9 panels in total:

That's a VOC of 36.80 x 3 --> roughly 110 volts going to the controller
The MNPV-4 box comes with "Four 15 amp fuses".

Just checking: Is that all you'd recommend I need for just the combiner box?

Do I need 'breakers' and if so, what size would you recommend?

(ps. not interested in the external disconnect switch option)

Again, I am no electrician, but I do need to order and install this myself.

Previous thread for more info

BB. · October 2012

Re: I'm pre-wired

The combiner box you chose uses fuses... Specifically these fuses. So, no breakers required.

From your solar panel data sheet, the maximum series fuse rating is 15 amps. All good there.

You do not need any additional circuit breakers in the Solar array to charge controller (fused combiner box is all you need). Note, it is not a good idea to "pop" out fuse holders to interrupt flowing DC current (they are not rated for "switch use" and can be damaged if "switched" under load).

You might want to measure up how much "extra MC4" cables you need and have some made to length (or get a male/female set and cut in 1/2 to wire in your own cabling--with appropriate wire insulation rating -- I.e., UV rated if in sunlight).

MC Interconnect Cables for Solar Electric Panels

And, if you want, you can ask further question in your original thread--It helps us to see what was discussed before and any equipment you may have already selected.

I can move this posts back to the original thread--if you wish. (it is "your thread" and you "manage" the discussion as best fits your needs. Recommend asking only a couple questions at a time to not distract every one into 10 simultaneous topics under discussion).

-Bill

vtmaps · October 2012

Re: I'm pre-wired

You can order that combiner from Midnite with circuit breakers instead of fuses. That specific box (prewired with breakers and connectors) may not be listed at NAWS, but Midnite will custom pre wire any of their boxes. By the way, that box will hold 6 breakers. Midnite also makes a box that holds just 3 breakers. You can order that from Midnite prewired with MC4 connectors.
--vtMaps

Surfpath · October 2012

Re: I'm pre-wired

BB. wrote: »

The combiner box you chose uses fuses... Specifically these fuses. So, no breakers required.

From your solar panel data sheet, the maximum series fuse rating is 15 amps. All good there.

I can move this posts back to the original thread--if you wish. -Bill

Hi Bill,
Thanks for the reply and for the confirmation about the breakers not being necessary if I order the box with fuses.
That'd be fine to move these posts to the original thread. My final panel specs differ slightly from those I supplied in the initial thread so I thought it'd be best to post new again. Either way it all works out fine.
Best,
SP

Surfpath · October 2012

Re: I'm pre-wired

vtmaps wrote: »

Midnite also makes a box that holds just 3 breakers. You can order that from Midnite prewired with MC4 connectors.
--vtMaps

VT, more good info. That's actually what I was hoping for. If it is a smaller enclosure, it'll fit the eve on my roof better. Will check it out.

Update - do you think this panel compliments this intended PV/Hydro system?

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