system install

System · September 2008

I'm taking my system parts and going to the cabin and installing them in the next couple of weeks. It is very small by most standards, but I still need some advice. I'm afraid I will forget a bunch of things when I go and want to attempt to get it all before I leave as there is no "Home Depot" within 200 miles. What I'm really looking for is a schematic of sorts or design plan that has the pieces of a system (e.g. wire, FUSING and other hard-to-figure-out tidbits) and where to install them. Also, given the size of my system, how big should the fuses be along the route? That's mainly where I'm confused. Thanks.

System at this point:

2 - KC130tm 130watt paralleled for 12 volts 7.39amps x 2 = 14.78Imax
1 - CC ProStar 30m at 12volts (intend on using the LVD)
4 - 6volt GolfCart (Sam's "trainers") - 210AH series/parallel for 12volts; 420AH / 50% = 210AH usable.

So:

1) Do I need a fuse between the panels?
2) What size fuse do I need between them and the CC?
3) Do I really need a combiner box or disconnects?
4) Do I need a fuse between the CC and the LVD connect?
5) What about a fuse for the Batteries?
6) Conduit or Not?

I've looked for a drawing but haven't found a detailed enough one. maybe someone can recommend a book that will help with the details? thanks for the help.

Tim

mike95490 · September 2008

Re: system install

Do you have a Battery Temp Sensor for your Charge Controller ?

I personally think, that an automotive 30A fuse, between the battery + and the Controller, will be all you need. All your loads coming off the controller ?

Does the ProStar 30 perform a Equalize cycle on the batteries ? With a series/parallel and flooded cell, you need to EQ once a month. Many controllers have a 30 day EQ timer in them.

What are your loads ? Have you done a power budget ? You are marginal on recharge power, for your 4 big batteries. If you drain batteries to the point of LVD, you will need 2 full days to charge back up, maybe more. (can you say "deficit charging" ? )

niel · September 2008

Re: system install

tim,
you should attempt to draw that out for yourself well in advance so you can go over it. drawings don't always indicate everything you might need as you may find need of say some electrical tape or screws to mount something and even the tools to do all of it as examples right off the top of my head. as you draw it on paper try to visualize the install as you plan to do it and hopefully you will realize what you have and need.
you can run the pvs to the controller seperately if you chose to do so if the cc allows for or makes accomodation for seperate inputs, but then you'll want to have individual fuses for each pv, whereas after your 2 pvs are combined that can then go into one larger fuse and travel back to the cc on fewer though larger wire to handle the increased current flowing. fuse ratings are in the specs for the pvs and if combining 2 then double that fuse rating. i believe they used 15a fuses for that pv, but be sure to double check me on that.
yes i recommend a fuse for the lvd and any and all connections made to the battery. conduit is a very good idea in a country setting because those critters eat anything.

System2 · September 2008

Re: system install

Installing at a remote location I would make one recomendation. Assemble you compleet system at home on a sheet of 3/4" plywood. That way you will have the availabiliy of parts, you wont feel so rushed, you will have plenty of power for tools and when you get it to camp it will just be a matter of bolting it in place. This will give you much more time for doing what you should be doing at camp. Enjoying it!!!!!!!!:D:D

niel · September 2008

Re: system install

good idea as a great deal of it could be preassembled and tested.

System2 · September 2008

Re: system install

personally, I love the fact that you can now get UL rated systems delivered fully assempled. Nothing quite like plug and play with a warranty.

mike95490 · September 2008

Re: system install

2 more words, a sketch, and 2 links

" Diagonal wireing "

Why:http://www.smartgauge.co.uk/batt_con.html

bonus - battery sizing (but ignore their hook-up sketches)
http://www.freesunpower.com/battery_designer.php

System2 · September 2008

Re: system install

mike90045 wrote: »

Do you have a Battery Temp Sensor for your Charge Controller ?

I personally think, that an automotive 30A fuse, between the battery + and the Controller, will be all you need. All your loads coming off the controller ?

Does the ProStar 30 perform a Equalize cycle on the batteries ? With a series/parallel and flooded cell, you need to EQ once a month. Many controllers have a 30 day EQ timer in them.

What are your loads ? Have you done a power budget ? You are marginal on recharge power, for your 4 big batteries. If you drain batteries to the point of LVD, you will need 2 full days to charge back up, maybe more. (can you say "deficit charging" ? )

Mike:

Yes, I bought a battery temp sensor. After reading this website it seemed like the right thing to do.

You say a 30 amp fuse. Why that particular size? How did you figure that? (This is one of my main quandaries!)

I originally planned for all loads to come off of LVD, but now I think I should just have DC loads come off of there and then put an infrequently used MSW invert directly off of batteries (?)

The Prostar does do an equalize charge.

I've done a very coarse power budget as I just got the cabin and have been there twice. It's still in the "building" stages, but it does have 12v "RV" lights built in. At this point, outside of charging a laptop battery and a stove fan, that's all there is. I'm guessing (and I mean guessing!) about 300-600 watthours.

mike95490 · September 2008

Re: system install

Your charger controller can handle up to 30A, Assuming you use 30A (8 GA) wire, and your loads via the LVD on the CC, 30A will support your max charge (15a from panels) and a lot of load, with no nuisance blowing.
If you add an inverter to the system, you will need whatever recommended fuse for it also, as close to the battery, so it protects more wire.

System2 · September 2008

Re: system install

niel wrote: »

tim,
you should attempt to draw that out for yourself well in advance so you can go over it. drawings don't always indicate everything you might need as you may find need of say some electrical tape or screws to mount something and even the tools to do all of it as examples right off the top of my head. as you draw it on paper try to visualize the install as you plan to do it and hopefully you will realize what you have and need.

I've now run through about half-dozen different drawings and it does help. Much like everything else when you're beginning, it's hard to decide on a "right" way to do it. But, very helpful and useful idea. Thanks.

niel wrote:

"you can run the pvs to the controller seperately if you chose to do so if the cc allows for or makes accomodation for seperate inputs, but then you'll want to have individual fuses for each pv, whereas after your 2 pvs are combined that can then go into one larger fuse and travel back to the cc on fewer though larger wire to handle the increased current flowing. fuse ratings are in the specs for the pvs and if combining 2 then double that fuse rating. i believe they used 15a fuses for that pv, but be sure to double check me on that."

I plan on paralleling them and then run a 6 or 8 guage wire to the CC. It depends on the final distance. But, since I am running them in parallel (at the panels) then do I need one 30amp fuse before the CC or a 15amp between them and THEN a 30amp fuse before the CC?

niel wrote:

yes i recommend a fuse for the lvd

The CC has a 30amp max out (and cut-off) from the LVD, so do I put a 30amp fuse at the output and then put appropriate wire to match the fuse?

This CC has a battery output which accepts max. 6ga wire. So I assume that is fine for the charging circuit and doesn't need to be battery cable (welding wire) size?

Thanks.

System2 · September 2008

Re: system install

thoughtforward wrote: »

Installing at a remote location I would make one recomendation. Assemble you compleet system at home on a sheet of 3/4" plywood. That way you will have the availabiliy of parts, you wont feel so rushed, you will have plenty of power for tools and when you get it to camp it will just be a matter of bolting it in place. This will give you much more time for doing what you should be doing at camp. Enjoying it!!!!!!!!:D:D

This is an excellent idea. I've begun the process and hope to have ALL the necessary components before I go to the cabin. Plus this helps me work out the issues I forget to put in the drawings.

niel · September 2008

Re: system install

my answers are in bold between your concerns.

Tim F. wrote: »

I've now run through about half-dozen different drawings and it does help. Much like everything else when you're beginning, it's hard to decide on a "right" way to do it. But, very helpful and useful idea. Thanks.

yes, it will help and i never implied it wouldn't, but as i said the drawings won't cover all of what you may need and is why i said to visualize your installing of the system.

I plan on paralleling them and then run a 6 or 8 guage wire to the CC. It depends on the final distance. But, since I am running them in parallel (at the panels) then do I need one 30amp fuse before the CC or a 15amp between them and THEN a 30amp fuse before the CC?

you could place a single 30a fuse after combining for 2 pvs no problem, but don't put the 15a fuses in there too as that's not necessary. if you opt for the 15amp individual fuses before combining then you won't need the 30a fuse for the combined output. one or the other, but not both.

The CC has a 30amp max out (and cut-off) from the LVD, so do I put a 30amp fuse at the output and then put appropriate wire to match the fuse?

i must admit that this is a grey area for me on this controller as when they state 30a to be a max i am not sure if this would be stating for you to limit the current to 30a like with a fuse or if the controller will do this for you. i lean that it needs a fuse until it to be shown otherwise.

This CC has a battery output which accepts max. 6ga wire. So I assume that is fine for the charging circuit and doesn't need to be battery cable (welding wire) size?

one cannot assume anything for it goes by the distance that current will have to travel that, in part, determines if that gauge is good enough to use. if you are familiar with voltage drops then you understand that the wire should be as short as possible. if you aren't familiar then look up the sticky on the voltage drop calculator.

Thanks.

modified for some stupid spelling errors on my part.

BB. · September 2008

Re: system install

Just as an FYI... The LVD output on most (all) solar charge controllers is really only good for supplying smaller DC loads (lights, radios, etc.)...

The LVD output should probably not be tied to an inverter that gets anywhere near the LVD rated current (much more than 100 watt rated inverter--30 amps * 12 volts = 360 watts--remember inverter surge is 2-3x rated load)... The high surge currents will either trip the Over Current Limit of the controller--or possibly fry the internal FET/Switch of the solar charge controller.

If, you want to use the LVD to control and inverter, then you would probably be better off using the LVD output to the Aux Power Control that is present on some brands/models of inverters.

-Bill

system install

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