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Post by JohnV on Nov 15, 2016 13:27:28 GMT
Solar is a new field for me, never having had any dealings with it before (In my book, it's ok knowing the theory but there ain't nuffin like hands on experience) I was considering getting from Bimble as follows for a 24V system3 x 260 W panels an MPPT controller However I was thinking of getting the 60 A Outback MPPT controller Instead of the 40A MPPT controller that Bimble recommend for that number of panels (My reasoning behind the Outback controller was to allow for increasing the number of panels to 4 or even 6 at a later date) What does the panel think Am I being OTT with the controller ? (Existing battery bank is a fairly new 280 Ah bank of Varta LFD140 sealed leisure and existing inverter is a 1500W there are no plans to change these at the moment)
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Post by tonyqj on Nov 15, 2016 14:15:15 GMT
What voltage are the panels?
It's sometimes better to have a second controller when you expand the system in the future as it allows better for one of the panels to be in shade etc, but that's a personal choice.
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Post by JohnV on Nov 15, 2016 14:28:57 GMT
High Tony O/C 37.85V S/C current 8.8A
If you are using more than 1 controller can they just be paralleled then? and do the controllers (as a general rule) need to be the same make or just the same type (I.e. MPPT or PWM)
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Post by bodger on Nov 15, 2016 14:31:39 GMT
because these controllers actively monitor and respond to system voltages, I can't see how you could use 2 in parallel; they may end up fighting with one another because they will not receive identical data.
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Post by smileypete on Nov 15, 2016 15:09:53 GMT
Solar is a new field for me, never having had any dealings with it before (In my book, it's ok knowing the theory but there ain't nuffin like hands on experience) I was considering getting from Bimble as follows for a 24V system3 x 260 W panels an MPPT controller However I was thinking of getting the 60 A Outback MPPT controller Instead of the 40A MPPT controller that Bimble recommend for that number of panels (My reasoning behind the Outback controller was to allow for increasing the number of panels to 4 or even 6 at a later date) What does the panel think Am I being OTT with the controller ? (Existing battery bank is a fairly new 280 Ah bank of Varta LFD140 sealed leisure and existing inverter is a 1500W there are no plans to change these at the moment) I'd tend to go with Bimble and get the Tracer 4215BN. But if you really want the Outback and can easily afford it then why not buy it? If you're off grid liveaboard with plenty of roof space (barge?) then maybe consider getting 4x 260W panels up front, it'll help stretch the solar 'season' further into early spring/late autumn. Have you done a power audit to see how much is being used at the moment? Inverters tend to be the big users so one way is just put some sort of AC power monitor on it, plenty on Ebay I'd have thought.
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Post by JohnV on Nov 15, 2016 15:12:17 GMT
What voltage are the panels? as they are in series and producing a high voltage should I use an ELCB or a 10mA RCD or an RCBO ...........
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Post by Deleted on Nov 15, 2016 15:15:41 GMT
Provided the two controllers are the same type ie MPPT or PWM then there shouldn't be a problem with having them operate in parallel. The common thing between them is the battery and they should both be set up for your battery type. On the panel side the two systems will be independent, ie one set of panels on one controller the other set on the other controller. Back to the original question, I would go for the recommended controller and if I added more panels later I would give them their own controller that way if one end of the boat is shaded the other half can keep going at max output.
I would look for a controller with a remote battery temperature sensor. So the controller can be in the warm and dry whilst still compensating for cold batteries.
Top Cat
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Post by JohnV on Nov 15, 2016 15:26:21 GMT
Solar is a new field for me, never having had any dealings with it before (In my book, it's ok knowing the theory but there ain't nuffin like hands on experience) I was considering getting from Bimble as follows for a 24V system3 x 260 W panels an MPPT controller However I was thinking of getting the 60 A Outback MPPT controller Instead of the 40A MPPT controller that Bimble recommend for that number of panels (My reasoning behind the Outback controller was to allow for increasing the number of panels to 4 or even 6 at a later date) What does the panel think Am I being OTT with the controller ? (Existing battery bank is a fairly new 280 Ah bank of Varta LFD140 sealed leisure and existing inverter is a 1500W there are no plans to change these at the moment) I'd tend to go with Bimble and get the Tracer 4215BN. But if you really want the Outback and can easily afford it then why not buy it? If you're off grid liveaboard with plenty of roof space (barge?) then why not get 4x 260W panels now if you definitely see them being used in future, possibly easier than mixing and matching different panels down the line. Mostly on grid but next summer will probably be off grid ..... did wonder about starting with 4, wired as pairs in series then paralleled giving the option of adding another pair in series at a later date, with no wiring alterations. Suppose really for a less than 20% extra cash it would be better. Do I gather from you saying that the 40A MPPT controller that it would handle the output of possibly 6 panels ? I had presumed the max current rating of the controller was the charge output to the batteries ( i.e. @24v) and not the current input from the panels ? was I leading myself astray there ? this was the reason that I was looking at the 60A outback controller.
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Post by Deleted on Nov 15, 2016 15:39:31 GMT
On our Victron controller they specify the max panel voltage which must not be exceeded and the max panel current that can. All that happens if your panels produce more current ( up to a point) than the controller can handle is it limits the current to that maximun. In practice this means you can connect a bit more panel capacity provided you dont go over the voltage limit. For example on my house I have 4Kw of panels feecing a 3.5Kw controller and everything has worked for 6 1/2 yrs.
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Post by JohnV on Nov 15, 2016 15:48:25 GMT
On our Victron controller they specify the max panel voltage which must not be exceeded and the max panel current that can. All that happens if your panels produce more current ( up to a point) than the controller can handle is it limits the current to that maximun. In practice this means you can connect a bit more panel capacity provided you dont go over the voltage limit. For example on my house I have 4Kw of panels feecing a 3.5Kw controller and everything has worked for 6 1/2 yrs. Top Cat Thanks Topcat It's making a bit of sense now. Right Gentlemen thank you very much. Modified spec then 4 Panels wire in 2 chains of 2 total power 1.04 Kw 4215BN 40 Amp MPPT controller. If I find I need to increase the array then use say 2 extra panels with a smaller MPPT controller running in parallel That gives me a 25% bigger array than I originally planned for a similar cash layout Thanks again
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Post by Deleted on Nov 15, 2016 16:18:45 GMT
Bear in mind that on days like today solar power doesn't do much. Today my home system has delivered 4% of what it can do on a good summers day, the output briefy peaked at 15% of maximum.
Panels only deliver their rated output under very specific conditions, usually cold , at 90 degrees to full tropical sun (read your panel spec carefully).
I seem to recall that some time ago Bimble solar were selling second hand or reject panels bougnt cheap from an Australian project. I have no idea what they are currently selling but a close look at the description would probably be a good idea.
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Post by JohnV on Nov 15, 2016 16:32:31 GMT
Bear in mind that on days like today solar power doesn't do much. Today my home system has delivered 4% of what it can do on a good summers day, the output briefy peaked at 15% of maximum. Panels only deliver their rated output under very specific conditions, usually cold , at 90 degrees to full tropical sun (read your panel spec carefully). I seem to recall that some time ago Bimble solar were selling second hand or reject panels bougnt cheap from an Australian project. I have no idea what they are currently selling but a close look at the description would probably be a good idea. Top Cat No, these are new grade A panels
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Post by smileypete on Nov 15, 2016 17:03:49 GMT
Probably still worth doing some sort of power audit, as a 1kW setup might be wayyy above what's needed, especially as they'll only get used in summer.
If you're after a winter project could always put 2 panels on now and a 20A Tracer controller, leave extra wiring in so you could double up later with another 2 plus another 20A controller if needs must.
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Post by Deleted on Nov 15, 2016 17:26:19 GMT
Good point Pete, we manage quite nicely on 200W in the summer, mind you we dont stay put for more than a day or so and we are frugal with power.
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Post by JohnV on Nov 15, 2016 17:47:44 GMT
Probably still worth doing some sort of power audit, as a 1kW setup might be wayyy above what's needed, I have an auto, power fail changeover system on the existing inverter. A back up for lights, central heating, fridge freezer and TV. I could split the system at that point and put insert a power consumption meter ........ I've got one kicking around somewhere. Probably not a bad thought ....... the central heating could be dropped off that circuit as I wouldn't have to budget for that in the summer. It's a big boat and even the lighting adds up to a fair amount (It's all 240v ...... yeah I know.....It seemed like a good idea at the time ..... it's a long story) I need to have a system up and running early next year so I am loth to delay the installation by splitting it into two installs. (I'm a geriatric boater so these jobs take 5 times as long as they used to when I was a mere whippersnapper in my 50's )
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