James Johnson's posts

what type of combiner box or ? do I need in order to run (2) ASC shunt controllers to the same battery bank?  Help please

thanks

I guess I need a copy of the NEC. Both books I have on PV

http://www.altestore.com/store/Solar-Electric-PV/American-Technical-Publishers-Photovoltaic-Systems/p5836/

and

http://www.altestore.com/store/Solar-Electric-PV/Photovoltaics-Design-Install-Manual/p481/

explain grounding well, but don;t speak very well with regards to Equipment grounding specs.

Thanks for the Help James, I'm working on my NABCEP certification

I have a small stand alone 12v nominal system with a battery bank. What size wire do I need for the equipment grounding conductor within conduit?

thanks for help

I have a midnight solar combiner, and(4) Kyocera KC40T modules in parallel going thru the combiner with individual breakers for each panel, this all goes to the controller

just trying to continue upgrading my system incrementally and see that adding in a Kyocera KD135SX-UPU would be a good cost/watt value. the Voc & nominals are pretty close

when hooking up multiple types of panels. IE: different Voc / Nominal. It's o.k. to mix them when they are all in Parallel?

OR Just get all the panels to be very close with regards to Voc?

perfect..I learned something new today..Thanks James..

James
I have a Midnite Solar MNPV3 with 3 Kyocera 40watt modules in parallel. I was thinking that I could get the larger MNPV6 and add more modules. BUT I thought that I could not add larger wattage modules..Like, if I add a 135 watt Kyocera module to a larger combiner and keep the 40 watt modules. Would the 135watt module be brought down to the 40watt modules output? OR is it because the voltage specs are so close AND that they are in parallel, that it doesn't matter what module I add in parallel, they will all behave nicely? I will need to upgrade my charge controller..

Ray,

Sorry to change the subject, but I'm really interested in your buss bar arrangement for the different sized solar panels. You mention an inline fuse for each different panel, then you are running all the positives to a common buss bar and all the negatives to a common buss bar and then feeding your charge controller off the pos & neg buss bars. What type of enclosure are you using to hold your inline breakers?

Do you have a pics of your buss bar set-up? I've been meaning to convert my set-up to one very similar to yours.

I'd be very grateful for any info you could send my way.

James

I feel like I'm getting close to the edge of learning on my own, with regards to installing a solar power system safely. My small off grid system has been up and running for a while now,but I would like to increase it's size and perhaps tie it into the grid in the future. I'd love to attend the Alt E classes, but unfortunately, the east coast is just too distant for me.

Are there similar groups out here in the Midwest that offer the same type of class (at the 300 level)? If so, can someone point me in the right direction please?

James

nice and professional...nice to have everything in "one" place and browse through.

I have wondered about the 6amp fuse rating as well...seems to be a bit high given that 2.65 x 1.56 = 4.134

perhaps it's because 5amp DC breakers are hard to come by and 6amps are not?..just thinking out loud

thanks for all the info in this thread guys

O.K. I got it....need to upgrade my combiner box to add in more panels...

Thanks Thomas & James for the info!

I currently (3) solar panels and have each individual Kyocera KC-40T panel on it's own wire and it's own breaker hooked into a 3 space Midnight Solar combiner box.

I want to increase my array and was wondering if I can parallel 2 panels by running wire between their junction boxes and then send the wire from this string to 1 slot of the combiner box?

I would need to increase the breaker by a factor of 2x? and make sure that the wire going from the parallel string to the combiner box can carry the amperage?

this would mean I could double my 40watt panel array size to (6) panels?

James

perfect! thanks for the reply James

right..I see that in the manual as well. I guess what I was really asking is if a buss bar is the best way to do this?

I want to add a second array to my system and want to know if adding a 2nd ASC shunt controller in parallel to my current one will work o.k. I plan on installing a Buss Bar for battery connections in order to simplify wiring and such and will be connecting the 2 ASC shunt controllers to it. These controllers should behave just fine together?


James

You mean I can trade in my Midnite Solar MNPV3 towards a Midnite Solar MNPV6?  that would very cool!

yes, I am using simple PWM charging with panels in parallel.

Is it Voc & Vpm that need to match if I were to mix in some larger Kyocera modules with my current KC-40t modules?

http://www.altestore.com/store/Kyocera-Solar-Panels/m38/Solar-Panels/1-to-50-Watt-Solar-Panels/Kyocera-KC40T-40W-12V-Solar-Panel-with-J-Box/p722/

I'm looking at the falling prices and am thinking now is the time to purchase.

modules I'm interested in:

KC-50t http://www.altestore.com/store/Kyocera-Solar-Panels/m38/Solar-Panels/1-to-50-Watt-Solar-Panels/Kyocera-KC50T-50W-12V-Solar-Panel-with-J-Box/p723/


KC-65t http://www.altestore.com/store/Kyocera-Solar-Panels/m38/Solar-Panels/51-to-99-Watt-Solar-Panels/Kyocera-KC65T-65W-12V-Solar-Panel-with-J-Box/p724/


KC-85t http://www.altestore.com/store/Kyocera-Solar-Panels/m38/Solar-Panels/51-to-99-Watt-Solar-Panels/Kyocera-KC85T-85W-12V-Solar-Panel-with-J-Box/p725/

James

Got all my panels mounted today and added photos of the IronRidge roof mount being used as a wall mount

http://gallery.altestore.com/James-Johnson-gallery/v/7059083552/?g2_page=2

interesting..I could have sworn that I can have a separate ground rod out at the panels that takes care of all the equipment grounding and then another rod for the neg side of power...at least this is shown in most every book & article I've read...

so sorry guys..I should have been more clear with my original post. I'm just grounding the frames of the panels..so sorry for the confusion. So what I need to know is the wire size needed for the EGC to the ground rod.

With that said, if Alt-E ever has a class on grounding, which seems to be the most esoteric item in fabricating a system, I would definitely fly across the country to attend!

James

You can add this one to the compatibility list for the Kyocera KC40T panel. I purchase one to try out and it fits very nicely. I'm using it mounted on the side of an exterior wall, in a "flipped" over position. I'll be adding 2 more of these, then I'll take some photos and upload to the gallery for people to see how I mounted them.

when grounding panels, should the grounding conductor wire size be sized for the total Isc x 1.3 of all the panels being connected to the grounding rod?

(3) Kyocera KC40t panels that I'm going to ground on one conductor.

Individual panels rated at 2.65amps x 3 x 1.3 = 10.34amps

the grounding conductor would then need to be able to carry say 12amps min?

OR would a larger wire be more better..

I see that the very same Kyocera KC-40T panel I purchased here not more than 5 months ago has gone up from $245.10 to $278.00!  that's a price increase of 13%+!  wow...

James

Thanks for the Exeltech reccomendation...just read thru their .pdf and they are definitely a fine product. Lowest harmonic distortion out there as far as I can tell. Which is critical for my use. Yes, I will be simply turning it off with a breaker when not in use, helps eliminate it's self consumption when not in use. Thanks again John

James

At what point does using an inverter become efficient? I understand the issues of energy loss due to conversion from the DC batteries to AC. But if an inverter is sized correctly for the job at hand, does the % of loss during conversion become a little more bearable? I have my current small system running completely in 12v DC, but have a few items that will be difficult to convert to using straight DC, hence the possible need for an inverter now. The size of the AC load will be smallish..around 300 watts. So, is there a good rule of thumb when looking for an inverter, in terms of sizing it for the load for better efficiency? I'm looking for a "Pure" sine wave inverter...any recommendations would be greatly appreciated.

Thanks

James

nothing but total satisfaction for me with AltE Store. I've purchased 100% of my system through them and they have absolutely the best customer service and shipping speed. They definitely go the extra mile with helping customers.

James

I did use UPS ground..though I am in the midwest and got my packages within 3 days of the shipping date. Good luck with your new system Michael.

O.K. NOW i think I got it....

since all my electrical boxes are in one place inside the garage, including the combiner and the baby box, I'll use (1) grounding electrode to ground equipment AND the NEG power conductor in the following manner:

NOTE: I DO NOT HAVE AN INVERTER. ONLY RUNNING 12V DC APPLIANCES.

the ground buss bar at the Midnight Solar MNPV3 combiner has attached to it the bare copper grounding conductor from the panel frames. Also attached to this ground buss bar will be a wire that connects the metal equipment boxes (baby box)(DC distribution box). Also attached to this ground buss bar will be a wire coming from the NEG side of my DC Power Distribution Box.

The ground buss bar is then attached to a ground rod via a grounding conductor of the same size as the largest wire coming from the Battery to the DC Power Distribution Panel.


look good..?!

found this nice grounding description at Affordable Solar. It appears that I just need to ground the frames and equip boxes to one ground rod and then attach the battery neg to another about 10'-0" away if need be.

Sorry for all the bandwidth about grounding. I just think it would be silly to get a hold of an electrician just to ground a 100watt 12v system...I'm sure I can figure this out eventually.

Maybe altE should have a specific ONLINE course in grounding..hint hint:)

To achieve effective grounding FOLLOW THESE GUIDELINES:

INSTALL A PROPER GROUNDING SYSTEM:

Minimal grounding is provided by a copper-plated ground rod, usually 8 ft. long, driven into the earth. This is a minimum proceedure in an area where the ground is moist (electrically conductive). Where the ground may be dry, especially sandy, or where lightning may be particularly severe, more rods should be installed, at least 10 feet apart. Connect or "bond" all ground rods together via bare copper wire (#6 or larger, see the NEC) and bury the wire. Use only approved clamps to connect wire to rods. If your photovoltaic array is some distance from the house, drive ground rod(s) near it, and bury bare wire in the trench with the power lines.

Metal water pipes that are buried in the ground are also good to ground to. Purchase connectors approved for the purpose, and connect ONLY to cold water pipes, NEVER to hot water or gas pipes. Beware of plastic fittings -- bypass them with copper wire. Iron well casings are super ground rods. Drill and tap a hole in the casing to get a good bolted connection. If you connect to more than one grounded object (the more the better) it is essential to electrically bond (wire) them to each other. Connections made in or near the ground are prone to corrosion, so use proper bronze or copper connectors. Your ground system is only as good as its weakest electrical connections.

If your site is rocky and you cannot drive ground rods deeply, bury (as much as feasible) at least 150 feet of bare copper wire. Several pieces radiating outward is best. Try to bury them in areas that tend to be moist. If you are in a lightning-prone area, bury several hundred feet if you can. The idea is to make as much electrical contact with the earth as you can, over the broadest area feasible, preferably contacting moist soil.

You can save money by purchasing used copper wire (not aluminum) from a scrap metal dealer, and stripping off the insulation (use copper "split bolts" or crimped splices to tie odd pieces together. If you need to run any power wiring over a distance of 30 feet or more, and are in a high-lightning, dry or rocky area, run the wires in metal conduit and bond the conduit to your grounding system.

WHAT TO CONNECT TO YOUR GROUND SYSTEM:

GROUND THE METALLIC FRAMEWORK of your PV array. (If your framework is wood, metalically bond the module frames together, and wire to ground.) Be sure to bolt your ground wires solidly to the metal so it will not come loose, and inspect it periodically. Also ground antenna masts and wind generator towers.

GROUND THE NEGATIVE SIDE OF YOUR POWER SYSTEM, but FIRST make the following test for leakage to ground: Obtain a common "multi-tester". Set it on the highest "milliamp" scale. Place the negative probe on battery neg. and the positive probe on your ground system. No reading? Good. Now switch it down to the lowest milli- or microamp scale and try again. If you get only a few microamps, or zero, THEN GROUND YOUR BATTERY NEGATIVE. If you DID read leakage to ground, check your system for something on the positive side that may be contacting earth somehow. (If you read a few microamps to ground, it is probably your meter detecting radio station signals.)

Connect your DC negative to ground ONLY IN ONE PLACE, at a negative battery connection or other main negative junction nearby (at a disconnect switch or inverter, for instance. Do NOT ground negative at the array or at any other points.