WHAT next?i picked up my morningstar controler......

[adamant]

thanks you all for helping me out in the past...

as to my last post (see link)

http://www.fieldlines.com/story/2004/9/21/35356/7878

my panel is being shipped this week and i already recieved my morningstar controler SL-20L-12V.....

NOW whats next?

what size wire do i use going from the panel to the controler? and to the battery?

this is going to be a cool add on to my cabin!

link to my shed;;

http://community.webshots.com/user/adamant117

link to battery question

http://www.fieldlines.com/story/2004/9/16/211518/393

[ghurd]

Hard part is done! Spending the money!

Get some coffee. This got long winded, even for me.

When do you spend more time in the cabin and need the most power from it? Summer, winter, or spring and fall. Ball park the Latitude from the internet, or get a buddy's GPS, to find a good mounting angle.

Good summer angle = Lat - 7 degrees

Spring and fall = Lat degrees

Wimter = Lat + 7 degrees

The panel must face South (I'd put it on the roof). The panel must have a mount, so there is nothing to restrict air circulation behind it for at least 6 or 8". This is important to prevent overheating.

Decide how mounting brackets will be fastened to the roof or whatever (For roofs, I thru bolt them with a 6x6" 3/4" plywood 'washer', metal washer, nylon insert lock nut, and a regular 'jam' nut.)

Now you can tackle the brackets. It takes less metal and stands closer to the roof when the PV is horizontal. Remember to figure roof slope in the finished angle. A weld shop with a bender can make them in a few minutes. Most look like a distorted "A" on stilts. Some people report good results with slotted angle iron commonly used for garage door instalation, I think it is kind of too weak, but it only takes a bunch of nuts and bolts and a hack saw...

Maybe the panel comes with factory wire. Probably not.

I use 12-2 w/g UF, the GREY type (all of the UF is sunlight resistant, but the grey is more resistant), connected to the PV box with a water tight strain relief. It's a 'romex' connecter with a rubber plug having a hole the size and shape of 12-2 wire, a big cap nut tightens the rubber around the wire.

I strip about 10" of the outer insulation, slide the strain relief down, fold the ground wire back 1/2" and wrap it around the wire so it can't pull out. The wire goes out the bottom of the box when it's mounted, and I like the PV box on the East end. If the panel has quick connects, crimp on the right size, then solder them with electrical solder (crimp ons don't work well with solid wire).

If the PV box has screws its easier. Bend them into a clock wise hook and tighten the screw, let it sit over night, tighten them again (suprising how much more)

I use Black for negative, white for positive. To avoid corrosion problems put some electrical grease on the terminals before and after they are connected (GB brand Ox-Gaurd is the commonly available type).

Opinion differs on sealing the box. Totaly sealed means a tiny leak will allow condensation and corrosion. Some people don't seal them at all to allow the moisture to escape. I seal the top and sides, but not the bottom, with silicone.

Bolt it up there. With luck, there is little or no twist to the panel sitting in place. On a roof getting the wire in takes creativity. Sometimes you can lift a shingle, drill 1/2" hole under it, feed in the wire, silicone it up, put a brick on it til the silicone cures.

Get the wire to the controller. Staple it every 3', not to tight. Leave an extra foot at the controller for future use. Remove 6" of grey insulation, strip 1/2" from the wires. I cut off the ground wire. Grease up the stripped wire and controller screws. Attach the wires.

DO NOT LET THE PV WIRES SHORT WHEN CONNECTED TO THE CONTROLLER. IT WILL DAMAGE THE CONTROLLER! This includes the use of ammeters across the PV terminals!

Use stranded wire from the controller to the battery. 10 or 12 ga. The controller end should have a crip on fork terminal (I solder them too). Grease them up, install. The battery end is up to you. The red and green felt washers battery washers work well against corrosion. The controller is temperature compensated, so it should be in with the battery.

Morningstar says to connect the battery, then the PV. Then they say it dosen't matter.

I left out fuses until now. Most people believe a fuse between the controller and PV should be there, and one between the controller and battery, rated 1.4X the panels output amps. Auto blade fuses in pigtails are a good choice, easy to see if it failed and the local '7-11' has fuses. I have never seen one blow in a small system.

Grounding is sure to get some replies! If you chose to ground the system you must use a DC lightning arrester or you have an expensive lightning magnet!

You could get a little fancier. Like a fuse distribution block handling all the fuses, making only one set of clamps to the battery. It would take some soldering skills.

I have some pic's if you need them. The Wife would have to get them from the camera card to here when she has time. Solar powering the camera is easier than working it.

Forgive the typos

G-

[richhagen]

Congats on getting the components.  Ghurd covered most everything.  Your trees worry me a bit as it seems you will lose a bit of power to shading over the course of a day.

I would position the panel at an angle and at a location favorable to the time of year when you are most likely to use the cabin and therefore need the most energy.  

Consider the trees, and where the sun will be during that time of year when choosing the exact location.  Vandalism and theft prevention may also be necessary considerations.

As for sealing the junction box, most manufacturers I've seen recommend it, however, I've observed water buildup inside the bottom of the junction box of one of my shell panels, maybe an imperfect seal?  This probably would have caused no harm as the junctions are mounted on the top as the panel is mounted.  As a result of this however, on the last panels I put up (PhotoWatt) I did not seal the bottom of the junction box even though they came with a small tube of silicone to do so.  Time will tell if there is any noticible corrosion on the connectors inside.

Your panel, by itself, isn't going to put out much more than 3 amps even in full sun shorted, so for the panel by itself you could probably run any wire 16 guage or more.  I would run at least a 12 guage wire and likely a 10 guage in the optimistic hope that if I could hook up more panels in the future, I could use the same wire (using diodes to keep current flowing in the right direction).  With one panel and the Morningstar Controller, I don't think you need a diode to prevent discharge of current into the panel at night, however check the liturature to make sure.

Keep Having Fun, Rich Hagen

[tecker]

   When the hardwoods drop their leaves you might get a good bit of sun to work with .

  The panels will be fun and informative .

 

[stm]

Hello,

It would be a good idea to weld a bolt or two when he is absolutely sure, that he is satisfied with the setup, just to make theft more dificult and time consuming.

- Noisy heist guys get a lot of attention :-)

/Steffen

[ghurd]

I use the 12 ga because it is the only size I can get a strain relief for.

Well, I can 'get' others for say 14 or 16 ga, but the total cost ends up more than with 12ga.

The ones supplied with most panels are for round wire. And I can't get the right UV resistant round wire.

The Photowatt silicone is an electrical, corrosion preventing grease (like Ox-Gaurd). It won't get solid. It also won't wash out of blue jeans very well.

The Photowatts instructions I've been using explain the good and bad of sealing the box or not. Mine said, if you want it sealed, get an O ring the right size, but they don't say what size that would be. These are the US panels, not the French made. The French made panels have a different box, which I like much better, but its not UL approved. It is CF approved for Canada. They are not importing the French panels to N. America anymore.

I like sealing the top and sides to keep water out, but not the bottom, so if it does get in, it can get out.

Don't use a diode with a Morningstar. Its in there. Extra parts will just screw up the works.

G-

[elvin1949]

good evening

a good alternative to welding is HEAVY DUTY LOC-TIGHT  300 ft lb torque to break it loose.

it is the RED type.

later

elvin

[nack]

Check you loc-tite tube, I am sure that it says inch-pounds.  I am not even sure if JB-Weld will take 300 ft-lb.

[Ungrounded Lightning Rod]

I use 12-2 w/g UF, the GREY type ... I strip about 10" of the outer insulation, slide the strain relief down, fold the ground wire back 1/2" and wrap it around the wire so it can't pull out. ... Get the wire to the controller. ... Remove 6" of grey insulation, strip 1/2" from the wires. I cut off the ground wire.

Gounding is sure to get some replies! If you chose to ground the system you must use a DC lightning arrester or you have an expensive lightning magnet!

If you don't run a ground to the panel, I expect you'd STILL have an expensive lightning magnet.  But in this case the lightning currents would split between traveling through the wood of your house (igniting it) and jumping between the frame and the panel wiring (damaging the panel) then through the controller (frying it) and coming out your DC wiring.

I'd run a protective ground from the panel frame to the house ground (perhaps via a cold water pipe) or (in wet-dirt areas) a separate ground rod, trying to keep any bends gradual (like 6" radius).  Down the OUTSIDE of the house, around the eaves, and down the side of the house to a rod is good.  It's tempting to use the ground in the panel wiring but that may be much less effective due to the narrow bends it's likely to take.  Think "TV antenna" and look in the books for how to handle that.

Regardless, if your panel takes a direct hit, it and your electronics are probably toast.  So your grounding and placement strategy should be driven by three factors:

 - Trying to keep the panel from getting hit in the first place.

 - Keeping the house from being ignited or people inside it from taking a lightning current if it gets hit anyhow.

 - Protecting your electronics from "surge" damage if something nearby is hit.

Avoiding hits consists mainly of making sure the panel is NOT the highest thing on your house.  (From lightning's viewpoint it's an easy path to ground whether it has the case grounded or not.  In the rapid E-field changes preceeding a strike it represents an equalpotential line from the lowest to highest parts of the wiring, concentrating the field around the panel.  So something else should do that even better for a longer run.)  Ideally it should be within a 45-degree cone under a better lightning magnet (like a nearby grounded metal tower or your house lightning arrestors or something serving that purpose, such as a grounded metal chimbney.)  In any case, if you must roof mount it, it should be low on your roof, rather than up at the peak where it is a lightning welcome mat.

Running a good frame ground is most of the battle to keep the house from being ignited by a direct hit.  The remainder is to discourage a fraction of the lightning current from going in through the wiring anyhow.  This consists of putting a couple narrow-radius half-turns in the feed wire (like a couple inches) to provide inductance, and a "surge arrestor" (the thing usually referred to as a "lightining arrestor") in the wiring AFTER the bends to drain off what makes it through the inductance or hops across it due to stray capacitance.  In the described instalation you have a partial turn where it goes under the shingle and through the roof - and it becomes a good half-turn if you then run it DOWN the rafter.  You can make another by bending the wire in a tight half-loop a few inches after it comes out of the shingle, and bringing it back a couple inches away from that, on its way to the panel.  This also doubles as the "drip loop" to keep rain from following the wire into the house.

A DC-rated surge protector just upstream of the charge controller completes the picture.  The ground from that should again be a straight run (no bends under 6" radius, the more gradual the better) to a good house protective ground (like a copper cold water pipe with continuity to the house ground).  If you use a protector in both the plus and minus lines you haven't "grounded" either of them with respect to the ordinary-operation grounding plan.

Please note that the above is from theory related to general cases rather than solar panels specifically.  I don't have field experience with installing solar panels and haven't done research on them.  I'll happily defer to someone with more authoritative info on properly lightning protecting photovoltaic instalations.

But I do note that I spent decades living in lower Michigan (where we get a thunderstorm a couple times a week all summer).  Among our personal-experience lightning stories is how the parent's hosue there survived two direct hits on TV and/or ham antennas installed according to this theory by myself and my brothers.  (Note that antennas MUST double as lightning arrestors since they end up being the high point - though they're usually wired only for surge protection and surviving a single hit = not repeated hits, which would require inch-thick twisted-polygon ground wire.  B-) )  The direct hit on the TV antenna vaporized part of the protective ground wire and left the house uncharred and the TV damaged but still operational (shrunken picture).  We considered that a victory.  B-)

[adamant]

thank you all for the great info...i will post a picture when i get it installed..

ant

[ghurd]

Where I work, solar is everywhere. Many hundreds, if not many thousands. NE Ohio, lots of Amish (Totally off grid and no cars for religious reasons, for you readers in other places. Could be an interesting Google for those not familiar?).

I know of only 3 that have been hit around here. There must be others too.

2 had been grounded by small wire (14ga?) from the frame straight to the ground. Isn't this just like a lightning rod? LOL That's why I mentioned the arrestor.

I don't know anything about the other one, just it got hit.

Grounding is a rare practice for these guys. I have to wonder how much it helps given the number of panels compared to the hits. Especially if consideration is given to the ratio of hits for grounded systems to ungrounded systems.

In all fairness, many of these are plastic framed mail-order "15/30/45 watt" deals. Maybe that plastic has something to do with it. Most all the panels are not too high.

For this case, the panel won't be very high (10'?). Lots of close tall trees. Batteries in a seperate 'dog house'.

Maybe mounting the panel on the battery's knee high dog house would help?

None of this is very scientific. It's just what I have seen.

'The Law' would need them grounded I am sure. So I won't recommend one way or the other.

G-