Solar Panel Installation - Montana Owners Club

**scottz** · 06-23-2017, 11:47 PM

Ok, starting to plan my solar panel system installation. I purchased the Renogy 400W kit with the Adventurer controller.

I'm thinking of installing the controller in the cabinet above the InCommand control panel and tying into the DC system on the back of the Progressive Dynamics Power Control Center. I'll come through the roof directly into the wall behind this cabinet. This will save me the trouble of pulling wires to the front battery compartment; in any case, there is not enough cable in the kit to reach the battery compartment.

The only issue I see with this is not being able to use the connections from the controller to the batteries (AGM) for temperature and voltage sense. As I understand it, these are optional.

Anyone see any problems with this plan?

Thanks

WaltBennett · 06-24-2017, 04:27 PM

Only caution I'd give you would be that it's most important to have your DC runs as short as possible and as large a gauge wire as possible. AC doesn't matter all that much, but that's probably why those cables that came with your kit are shorter than you'd like. I mounted my panels pretty much above our bedroom and bath, and ran the cables down from the roof through a dead space behind the medicine cabinet, straight down into behind the back basement wall. From there, through the basement to the front bulkhead where I mounted my Morningstar charge controller next to the batteries. My inverter is back on the other side of the bulkhead in the basement, and I ran two AC lines between the inverter across the top to the AC panel. The inverter has a remote and I mounted it next to my Triminic battery monitor. See my post here: http://www.montanaowners.com/forums/...ighlight=solar

Lenny K · 06-24-2017, 08:02 PM

Walt has it right. Get that charge controller as close to you batteries as possible as well as the inverter.

**scottz** · 06-24-2017, 10:25 PM

Thanks.

I've been out there for several hours planning it. I came to the same conclusions. I think I will run the PV cables (they gave me 30') into the basement and mount the controller next to my inverter on the front wall. The other side of the wall is the battery compartment.

I have to order fuses and fuse holders so I won't be able to finish this weekend. It would be nice if they supplied those.

They did provide a roof entry; that was nice.

WaltBennett · 06-25-2017, 05:54 AM

I just used air conditioner disconnect boxes. The heavier duty ones are at HD or Lowe's. Wired one side of one between the panels and charge controller and the other side of it from the charge controller to a marine distribution strip (Amazon) that has the batteries, inverter, the old converter and the 12 volt feed to the trailer. Used a second box's one side to fuse the batteries. The other side of it fuses the inverter. Only issue I've had is that the eBay purchased 4kw inverter I've got can put out more than 80 amps DC to charge the batteries and will blow fuses if the batteries are below about 85% on the Triminic. (That AIMS inverter is a monster!) I'll either let the solar charge them or turn on the old converter - it won't do more than 50 or so amps.

Mudchief · 06-25-2017, 09:00 AM

I don't know what size wire they sent you but the loss between the solar panel and the controller is very important. 12 volt panels need larger wire than 24 volt panels.

**scottz** · 06-25-2017, 01:00 PM

The sent me 30' of #10 for the connection to the panels. Some more #10 to go to the batteries.

**scottz** · 06-25-2017, 01:03 PM

Quote:

Originally Posted by WaltBennett

Only issue I've had is that the eBay purchased 4kw inverter I've got can put out more than 80 amps DC

And here I thought an inverter took DC in and put out AC.

WaltBennett · 06-25-2017, 01:28 PM

Quote:

Originally Posted by scottz

And here I thought an inverter took DC in and put out AC.

It's an inverter/charger - even has a solar charge controller in it, but I'd already put in the Morningstar. I'm still surprised the eBay seller let me have it for $615. I figured that since I would only be using about 1kw of it's 4kw capacity typically, even though it was an AIMS, it should last. So far it has.

WaltBennett · 06-25-2017, 01:30 PM

Quote:

Originally Posted by scottz

The sent me 30' of #10 for the connection to the panels. Some more #10 to go to the batteries.

That should be good from the panels to the controller, but I'd go heavier from the controller to the batteries. It's the amount of current you will have going through them (as well as being DC and the voltage).

**scottz** · 06-25-2017, 05:15 PM

Quote:

Originally Posted by WaltBennett

It's an inverter/charger - even has a solar charge controller in it, but I'd already put in the Morningstar. I'm still surprised the eBay seller let me have it for $615. I figured that since I would only be using about 1kw of it's 4kw capacity typically, even though it was an AIMS, it should last. So far it has.

I figured it must be some kind of combination unit. That's a good price. I paid $499 for my 2k pure sign wave inverter.

Mel B. · 06-25-2017, 05:50 PM

Quote:

Originally Posted by WaltBennett

It's an inverter/charger - even has a solar charge controller in it, but I'd already put in the Morningstar. I'm still surprised the eBay seller let me have it for $615. I figured that since I would only be using about 1kw of it's 4kw capacity typically, even though it was an AIMS, it should last. So far it has.

Walt
How many amps does it draw at Idle? must be alot. And my Renogy 2000 watt inverte/charger ,is 70 amp charger but it has a adjustment so I can go from 70a to 0a as needed. Nice feature

Mudchief · 06-25-2017, 07:00 PM

Scott, 10 is ok for 24 volt panels but if yours are 12 volt I would not use anything smaller than number 4.

**scottz** · 06-25-2017, 10:32 PM

Quote:

Originally Posted by Mudchief

Scott, 10 is ok for 24 volt panels but if yours are 12 volt I would not use anything smaller than number 4.

I wonder why they sent #10 with the kit?

https://www.renogy.com/renogy-400-wa...-solar-rv-kit/

mjammersc · 06-26-2017, 05:49 AM

#10 from the panels to the charge controller may be OK depending on where your kit combined the panels together. The diagram on the link looks like they parallel them together so after they are paralleled (the 2 into 1 * 2 junctions) will be where you will need shorter runs of 10 or larger gauge wire preferred. Your panels actually run ~17-18V and put out 5-6A. As you combine them, the voltage is staying the same but the current is adding so that is where larger gage wire would be better.. From the charge controller to the battery is where you will need larger as well because the charger will be putting out ~25-30A when you have good sun.

Best thing to do is do some calculations using the voltage drop calculator such as in this link, as you should try to keep the total line loss from the panel to the battery at less than 3%. Make sure to use the right voltages (~17.5V & 5.5A from each panel) and ~14.5V and 27.5A from the charger to the battery - this is around the peak bulk charge voltage and current). Your wires between batteries and from the batteries tot he inverter are the ones to watch even more as a 2000W inverter will pull over 150A if you max it - running the microwave or something like that will be in the 125A range.

http://www.calculator.net/voltage-drop-calculator.html

**scottz** · 06-26-2017, 09:11 AM

Thanks!

Using that calculator and 10awg, my voltage drop between the panels and the controller (30') is 1.89%. From the controllers to the batteries it is 4.1% if I use all 10’ of cable; I think I will only need about half that for a drop of 2%.

I use 2/0 welding cable between batteries and to connect the inverter to the batteries.