Adding a second lot of panels

Bigfillly

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Aug 20, 2017
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103
Hi,
I have 10 panels on a roof that faces south going to my pip 48v inverter, I want to add another lot of 10 panels on another roof that faces west to get the last of sun from 14:00 till it goes down, can I connect the second lot of panels to the inverters input (where the other 10 panels are connected) or do I need to put them in series with the other panels?
Thanks very much,
Phil.
 
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Agreed, panels facing different directions should be on separate charge controllers. Putting them together you could actually end up with less solar input then you have at the moment.
 

Bigfillly

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Aug 20, 2017
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I probably should have said the first lot are going to my pip5048 charge controller/inverter as I have batteries,
are you saying I cant join them at the charge controller and I need another charge controller/inverter for the second lot of panels?
Is there not a way round fitting them to the same charge controller/inverter.
Thanks,
Phil.
 

Sean

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BaronVonChickenPants said:
Agreed, panels facing different directions should be on separate charge controllers. Putting them together you could actually end up with less solar input then you have at the moment.

How are you defining "less input"
 
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There are a lot of variables to consider such asshade, fuses, back-feed diodes, total array voltages, individual panel specs, etc. but as a simple answer to a simple question with limited information provided, merging two arrays facing separate directions could result in less overall charge being delivered to the batteries.

If the panels are similarly spec'ed and you were to install back feed diodes to each string, you could add additional panels in parallel strings, you would also need to consider the total array size compared to the rated capacity of your charge controller.

It can be done but it would be easier and is recommended to use a separate charge controller.
 

Sean

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BaronVonChickenPants said:
......merging two arrays facing separate directions could result in less overall charge being delivered to the batteries.

"charge" being measured in what units ?


Bigfillly said:
Hi,
I have 10 panels on a roof that faces south going to my pip 48v inverter, I want to add another lot of 10 panels on another roof that faces west to get the last of sun from 14:00 till it goes down, can I connect the second lot of panels to the inverters input (where the other 10 panels are connected) or do I need to put them in series with the other panels?
Thanks very much,
Phil.

Assuming both arrays are reasonably well matched in terms of string power and voltage, and are not overly shaded, andthe inverter is able to safely handle theinput current, combining 2 arrays into a single MPPT input will likely result in a few percentage points of decrease in maximum power, but due to virtual tracking the daily production will be greatly increased.

Multiple, dual aspect matched arrays into a single MPPT inverter was common practice untill multi MPPT inverters became more readily available - you do realise that the west facing array will be very unproductive during November through till late March - sooverall you'll see a lower peak daily power, but longer productive hours with splitarrays.


BaronVonChickenPants said:
There are a lot of variables to consider such asshade, fuses, back-feed diodes, total array voltages, individual panel specs, etc. but as a simple answer to a simple question with limited information provided, merging two arrays facing separate directions could result in less overall charge being delivered to the batteries.

If the panels are similarly spec'ed and you were to install back feed diodes to each string, you could add additional panels in parallel strings, you would also need to consider the total array size compared to the rated capacity of your charge controller.

It can be done but it would be easier and is recommended to use a separate charge controller
.

Well edited.

I disagree with the last sentence.
 

Korishan

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2 different charge controllers should be used when panels are facing different directions. Each set of panels will have different maximum power points. If they are connected in parallel they will be dragged down to the lower voltage. If they are in series, they will be dragged down the lowest amperage.

2 different charge controllers doesn't mean 2 physical controllers. If a controller has 2 inputs, then it probably has 2 mppt controllers built in. Some have 3, others have 4. Just depends on what you bought. But I don't believe the PIP5048 has more than 1 controller built in.
 

OffGridInTheCity

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Dec 15, 2018
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Its not clear to me from your initial comments that you have separate charge controller from the inverter. If you do, you can add a 2nd charge controller (for the new PV array) and combine that output with the other charge controller to the single battery/inverter. This works great - just match charge settings on each controller to be the same for the single battery. If you actually have a charge controller/inverter as a single device, then to add a 2nd (similar) device would leave you with 2 separate inverter outputs. If this is off-grid, then not so easy to see how you would consume the 2 different AC output streams... and you might want to go to a separate controller / inverter system - and then have 2 controllers as discussed above.
 

Bigfillly

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Aug 20, 2017
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103
Wow, Thanks for all the comments,
I cant see another input for panels on my pip5048 So I guess it only has one mppt,
This is my setup

image_ehchmc.jpg


image_fveeoq.jpg


image_ijgxzy.jpg

As you can see I also have a pcm60x to charge the batteries,
I wanted to fit another lot of panels in with the first lot of panels on the only input (the yellow line in pic one)
The panels I have are very close to the other panels Im using on the pip5048
I realise that there wont be must gain in the winter month but where my panels are it gets shaded around 16:00 but the front of my house still has sun, I want to get ther last 3-4 hours of sun in the West,
What Im trying to say is, when the West panels are fitted and working (16:00 onwards) my south panels are in the shade, so as long as when I first plug the second (West) lot in, my system doesnt drop to the lowest it sees (the west side panels) it should be ok,
I think I might need a few back feed diodes though.
 

OffGridInTheCity

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Dec 15, 2018
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I looked up a pip5048 this is what I found.

image_ayzjpj.jpg



Based on this, I would suggest you buy a 2nd pip5048 and hook up the 2nd PV Array to it, hook this 2nd one tothe existing battery bank, and perhaps ignore the 230v output as presumably you are happy with the exiting AC wiring on the 1st one. This second one will thingtake in the power from the 2ndPV array and charge the battery bank (for use by the 1st one to generate AC power).

Full disclosure - I use mutliple Midnite Classics to same battery just fine... but I'm not anMPP Solar (equipement/settings) expert. So please confirm this suggestion elsewhere before spending $$.
 

Powersaver

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Jan 8, 2019
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As Sean says, you should be able to install a second set of panels on the same MPPT without a lot of losses. (So you run you panels as 10S2P). If you want absolute maximum output you need a second MPPT but i'm not sure it's worth it.

I would install the new set of panels in parallel on your existing setup and see what you get. If it's not providing as expected i would then look into getting another MPPT, but just a basic battery charger, not a whole inverter package as OffGridInTheCity recommends. It would be a total waste of money to buy a new inverter if you don't need the extra DC to AC capacity.
 

Redpacket

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Feb 28, 2018
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Like others have posted, having 2 MPPT inputs would be best
But acceptable to be two isolation diodes & feeding the PIP's 1x input.
Another option might be to use another MPPT charger only (ie vs a combined charger inverter)
 

RikH

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Nov 22, 2018
Messages
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Bigfilly everybody is assuming your PIP has a MPPT controller. But as fa as I can see you have a PIP5048HS and the HS series have PWM controllers. Here are the specs. It also has a max of 90 Voc input and since most panels have higher than 30 volts Voc you can only make series of 2 panels and you have to parallel 5. result is very high currents (which the PIP can handle) and thus big fat cables. I would recommend another MPPT charger preferably with a high input voltage. Are you off grid or are you feeding back in as well?
 
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