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Author Topic: Solar panels and controller arrived. How to install?  (Read 351 times)

Frank B

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Solar panels and controller arrived. How to install?
« on: June 15, 2017, 11:45:58 AM »
Time to start a new thread.

I have been researching the idea of adding more solar to our Arctic Fox, as noted in this thread.

I already chose my panels and Outback FM-80 controller as noted in this thread.  They arrived via Fedex today.

Now comes the installation.

I am planning to use plastic outside conduit to run the wiring through.  This stuff is designed for outdoor use, so I plan to use wire that does not have UV protection in the insulation.  The conduit will do that, and there are already clips made to attach that to an outside surface.

Kevin:

You showed me  how you did the wiring on your motorhome in this thread in reply 14.  I would be interested in knowing where you got the terminal bars.  You already explained the different gauges of wire you used, and how only one pair of heavy gauge wires went from the junction box to the controller.

Also, the sloped panel ahead of the junction box: Is that there solely for aerodynamics, or is that panel over another box that is  partially sunken into the roof?

What type of junction box did you use?  I was up to Home Depot yesterday just having a quick look, and the boxes I saw had no holes in the sides at all (knock outs) through which one could pass wires.  The boxes I looked at also do not have weather seals around the cover.  Do they make them with o-ring seals, or does one just sliicone the joint?

Thanks for any help you can provide.

Frank Billington
Linux:  Free, open, elegant.
06 GMC 3500 Duramax crew/long pulling 2010 Arctic Fox 30U with 1700 lb Reese Titan Class 5.
1.2 kw solar

Gizmo

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Re: Solar panels and controller arrived. How to install?
« Reply #1 on: June 15, 2017, 12:42:05 PM »
As far as junction box goes, it is possible to make up your own using parts from Home Depot, Lowe's etc.  However when I did my solar on my previous rig, I purchased the combiner box from AM Solar.  Pricey yes, but it made the install much, much easier, quicker and made future additions, subtractions and service work very simple.  I was very happy with it and will be purchasing another for my new rig when I begin my solar project.  Also they have two kinds, one a stand alone unit and a second for routing wiring through a fridge vent.  I was not able to make use of the fridge vent so I opted for the stand alone combiner box.  I mounted my box under one of the solar panels, but this was my choice and not required.
Regards, Bruce, Lin An, Kenji & Suki
2017 Eagle Cap 1165 Truck Camper With Tork Lift Fast Gun Tie Downs & T.L. Wobble Stoppers
2015 Ram Big Horn 3500 CC Cummins TD Dually 3:73 Gears & AISIN Tranny
Gone But not forgotten:
2014 Northwoods Snow River 246RKS &
2013 Aliner Expedition

Kevin Means

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Re: Solar panels and controller arrived. How to install?
« Reply #2 on: June 15, 2017, 07:40:42 PM »
Hi Frank. I got the bus-bars for my junctions boxes at Home Depot, which is where I also got the junction boxes. I have two junction boxes (Picture 1) - one for my solar panels, and one for the electro-mechanical tilting devices. https://www.youtube.com/watch?v=IoSv6Rk9ZMo The boxes are (supposedly) weather-proof and they have rubber O-rings built into the removable tops. So far, they've held up well.

Picture 2 is a shot of one of them opened up. Like Gizmo said, you can build your own pretty easily. That's what I did. The wiring is straightforward and simple. I drilled holes in the side of the boxes to route the wires and installed some guides (if you will), which tighten up to prevent water leaking in around the cables. I also put Dicor around them and I've never had any leaks.

Picture 3 is a shot of my Outback FM-80 with two 250 amp DC switches. Those switches allow me to cut the power from the panels to the controller, and from the controller to the battery-bank. Makes doing maintenance much easier. Picture 4 shows where I installed the controller and switches. It also shows where my house battery-bank is (beneath the floor panel) and where I installed two additional AGMS.

That sloped panel that was in front of the junction box, was put there to help guide branches and things away from the side of the junction box. When I installed the second junction box for the tilting devices, I did not install that guide. I just haven't needed it (crossed fingers)

Kev
« Last Edit: June 15, 2017, 07:50:43 PM by Kevin Means »
2011 Winnebago Tour 42QD
Towing a Jeep Rubicon Unlimited LJ or an Acura MDX
RVI Brake 2, Minder TM-66 TPMS, 970 watts of solar
(Can't wait to spend more time RVing)
Lakeside, California

Frank B

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Re: Solar panels and controller arrived. How to install?
« Reply #3 on: June 16, 2017, 02:01:09 PM »
Kevin:

I found some weatherproof boxes that will fill the bill at Home Depot.  I was not looking carefully enough before.  Couldn't find bus bars, however, so I may have to try an electrical outlet.

Where did you get the high-amp DC switches?  And, isn't 250 amp substantially more than needed?  :)

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That sloped panel that was in front of the junction box, was put there to help guide branches and things away from the side of the junction box.

Ah.  Makes sense if one uses one of those tall plastic boxes for a junction box.  I think my junction box is going to go just behind the fridge vent, which should give some protection.  Hopefully, I will also be able to get one that is not that tall.

My solar panels call for 12 gauge wiring, and the longest run I am going to have from panel to junction box is just over 10 feet.  How much loss am I looking at if I use 12 gauge solid house wire?  I can't imagine it would be much over that distance.  I'll use something much heavier between the junction box and the controller, which is a run of about 18 feet.  I plan to mount the controller right beside the converter, so that run will be really short.

Finally, these panels come with 12 gauge leads soldered into the box on the back of the units.  The leads terminate in PV-JM601 connectors, which are not that common, it would appear.  I'm still deciding if I am going to cut them off in favor of something easier to work with, like a waterproof  automotive style connector, or see if I can order a dozen of those connectors from somewhere. 

One of the things that I appreciate with our trailer is that when they built it, they left enough slack on the electrical so that appliances can be removed without having to cut off the wires.  I would assume that this would be good practice on the panels as well should I ever have to remove one.  Is there a 'best practice' with regard to leaving a loop of wire on the back of the panel to give enough 'slack' to allow it to be removed easily?

Thanks.

Frank.
Linux:  Free, open, elegant.
06 GMC 3500 Duramax crew/long pulling 2010 Arctic Fox 30U with 1700 lb Reese Titan Class 5.
1.2 kw solar

Kevin Means

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Re: Solar panels and controller arrived. How to install?
« Reply #4 on: June 16, 2017, 04:49:37 PM »
If one of your panels is putting out about 21 volts and 8 amps on a good day, a 10 foot run of 12 gauge copper wire will have a 1.19% voltage loss, or about .25 volts. That's fine, and well within the 2% max loss recommendation.

Yes, those 250 DC amp switches are overkill, but it certainly won't hurt anything to use them, they're pretty robust and were cheap - about $25.00 each. I got them online, but I don't remember where - sorry. They're not hard to find. Car parts stores often carry them, because they're built to disconnect car batteries.

I'm not real familiar with the way your panel's wires are connected. The most common way I've seen is to have the panel-end of the wires go into a weatherproof box on the back of the panel. I don't know how they're attached to the panel inside that box. The loose ends of the wires usually have male and female MC4 connectors on them. It's not like you're going to be taking them on and off all the time,  so any good weatherproof connection should work fine.

I have a little slack for each of my panel's wires, because our panels tilt. There's about two feet looped under the panel itself. You can't even see it, and the cables don't flop around at all.

Kev
« Last Edit: June 17, 2017, 09:31:03 PM by Kevin Means »
2011 Winnebago Tour 42QD
Towing a Jeep Rubicon Unlimited LJ or an Acura MDX
RVI Brake 2, Minder TM-66 TPMS, 970 watts of solar
(Can't wait to spend more time RVing)
Lakeside, California

Frank B

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Re: Solar panels and controller arrived. How to install?
« Reply #5 on: June 19, 2017, 09:46:34 AM »
Kevin:

Quote
Those switches allow me to cut the power from the panels to the controller, and from the controller to the battery-bank. Makes doing maintenance much easier.

What kind of maintenance would require a big switch to isolate things, and why?

I can see a possible need to shut off the solar when plugged in to shore power, but is even that necessary?

I think I will just cut off those odd weatherproof connectors on the panels, and use something more standard.  I'll see what I can find in an auto parts store first, and if nothing looks good, I'll go buy a more common solar connector, like the MC4 you mention.

Next step will be to buy some aluminum angle to make mounting brackets out of.  I plan to bolt them on to the sides of the panels where I can get at the stainless machine screws I plan to use rather than use a Z bracket that bolts to the bottom of the panel where it will be hard to get at the bolts.  Should I need to remove / replace them, I would rather remove the bolts than to disturb the dicor-sealed wood screw attachment to the roof.

Frank.
Linux:  Free, open, elegant.
06 GMC 3500 Duramax crew/long pulling 2010 Arctic Fox 30U with 1700 lb Reese Titan Class 5.
1.2 kw solar

Gizmo

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Re: Solar panels and controller arrived. How to install?
« Reply #6 on: June 19, 2017, 01:11:50 PM »
No need to cut turn off the solar power when plugged in.
Regards, Bruce, Lin An, Kenji & Suki
2017 Eagle Cap 1165 Truck Camper With Tork Lift Fast Gun Tie Downs & T.L. Wobble Stoppers
2015 Ram Big Horn 3500 CC Cummins TD Dually 3:73 Gears & AISIN Tranny
Gone But not forgotten:
2014 Northwoods Snow River 246RKS &
2013 Aliner Expedition

Kevin Means

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Re: Solar panels and controller arrived. How to install?
« Reply #7 on: June 22, 2017, 09:25:11 PM »
Hi Frank. Sorry I didn't get back to you sooner. I've been traveling (airlines) and just got home. Gizmo's right, it's not going to hurt anything to leave your panels and controller connected while hooked up to shore-power.

I installed D/C disconnect switches between the controller and batteries, and the panels and the controller, for two reasons - so I wouldn't have to worry about hot wires IF I decided to do any maintenance on the system, and in case the coach was going to sit outside, unused for extended periods of time.

Like I said, it shouldn't hurt anything to leave the solar setup connected, because the controller won't allow the panels to over-charge the batteries when plugged in, but I've just never been a fan of leaving things powered up for extended periods of time if they're not being used. I just wanted a simple way of shutting everything down.

Bottom line... you don't "need" disconnect switches. I just like having them. If you do decide to install them, you don't need switches with that high of an amp rating. The switches I installed are just  standard battery disconnect switches, and that's their amp rating. I would recommend, however, that you use D/C switches, as opposed to A/C switches.

Kev
2011 Winnebago Tour 42QD
Towing a Jeep Rubicon Unlimited LJ or an Acura MDX
RVI Brake 2, Minder TM-66 TPMS, 970 watts of solar
(Can't wait to spend more time RVing)
Lakeside, California

Frank B

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Re: Solar panels and controller arrived. How to install?
« Reply #8 on: June 26, 2017, 09:07:12 AM »
OK, installation begins today...

I had looked at buying a z bracket kit here locally for installation, but decided not to for 2 reasons: 1) they are WAY too expensive here and 2) I think I prefer to attach the brackets to the sides of the panels rather than the bottoms.

I had the local Metal Supermarket cut out 36 brackets from 1" x 2" aluminum angle.  Not only were they less than half the cost of z brackets here locally, but I can also attach them to the sides of the panels rather than the bottoms where the screws will be almost impossible to access.  Should I need to remove a panel for some reason, I would have to take the screws out of the roof rather than the stainless machine screws from the brackets.  I prefer to mount and seal them to the roof once, as in my mind at least, I am less likely to create a leak.

I decided on 6 brackets per panel rather than the customary 4 due to the comments here about possible vibration damage to these big panels in a mobile installation.  An extra mount in the middle may stabilize them.

Today I will begin attaching the brackets to the panels.  That will probably be an all day job, as I will have to drill all the holes in the brackets and the panels, then attach everything with stainless machine screws and lock washers.  However, I am retired, so I have the time.

The next step will be to put the panels on the roof, and 'fine tune' exactly where I will attach them.  Once that is determined, I can cut my plastic conduit and assemble it without glue just to make sure all is well.  When satisfied, I will move the panels to the carport roof (my flat carport roof is the exact same height as my trailer roof, which is convenient), glue together the conduit, attach it to the roof, and pull all the 12 gauge wiring where it needs to go.

I am using 'T' boxes with weatherproof lids to branch the wires off to the panels, and plan to mount all but one of those boxes under the panels where they will be even less likely to suffer from the weather.  I have plastic caps for the ends of the conduit where the wire will need to come out of the conduit to connect to the M4 connectors on the panels.  Those caps have a compressible collar to seal the wires, and I will add silicone sealer as well.

The one 'T' box that will likely be exposed to the weather is where the wiring from 4 of the panels will have to come together.  That box will be 3/4" conduit instead of the 1/2" everywhere else.  An electrician friend tells me that 1/2" conduit is good for 7 x 12 gauge wires, and I will need 8 of them in a 50" run across the roof to the junction box where wiring from 2 more panels will join the array.  Once the wiring is in place, I hope to then  screw down the panels to the roof.

From the junction box we take heavy gauge wire (haven't calculated the size yet) and go down the fridge vent, through the cupboards to where I will mount my solar controller, which will be in the same cavity where the converter is already mounted.  The panels are 205 watt at 40 volts (optimum), or just over 5 amps per panel (short circuit), for a total current of 30 amps under a perfectly blue sky at noon on the equator.  :)  I expect about  half that on a good day, so I am figuring a max of 20 amps over a distance of just under  18 feet to the controller.

So, now to start attaching brackets....

Eventually I will post pix of the installation process, but I have little to show at the moment.

Frank.
« Last Edit: June 26, 2017, 09:10:10 AM by Frank B »
Linux:  Free, open, elegant.
06 GMC 3500 Duramax crew/long pulling 2010 Arctic Fox 30U with 1700 lb Reese Titan Class 5.
1.2 kw solar

 

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