Quick MPPT question

[BradKW]

I considered Blue Sky, but it seems they focus on smaller solar setups...I never saw a product for 1kW applications. But I've found that even when looking at a manufacturer's site, it's easy to miss what you're looking for do to poor site designs, so if you know of something please link it...

 

[SternWake]

I think the strategy employed by blue sky is multiple controllers in parallel.  I know my IPN pro remote can supposedly parallel and monitor input from 7 different BS controllers.

I understand the desire for just one larger controller though.

 

[Canine]

Bid on 2 mppt controllers on ebay and "WON"(their term).Both are 30 amp,so I will be able to compare them to my pwm controllers much easier.I won't be able to install them until fall,but I'll take them apart and check the components,soldering etc.If they work as I have been led to believe,I'll buy 4 more for the rest of the system.

 

[rvpopeye]

More info please !
Brands , winning bids , specs , and PICS !

 

[blars]

Some of the ebay "mppt" controllers aren't even decent pwm controllers.

 

[jimindenver]

Bob

What units did you win? When taking them apart look for a induction coil for the buck converter. That is required for MPPT.

 

[Canine]

Blue Sky.30 amp.I normally have plenty of power but can use a little more on cloudy days.If they work as advertised,I'll go mppt all the way.And apologize to Bob for doubting the benefits he claimed.

 

[jimindenver]

Not too shabby especially with a good deal. It will be good to have a side by side comparison not just of peak output but of early on when the voltage is low as well as cloudy conditions. Everyone goes for the peak when the real advantage is in the other two. Just think, you might just be the next poster boy for MPPT.

I seem to remember you having a good sized system. What are the panels and what is the voltage of the bank?

 

[Canine]

Poster Boy?Does that require me to remove my clothing?I have 24 panels,all 100 watt.Set up for 12 volt.I am going to put 4 panels on the camper and leave them there if the new controllers work out.

 

[jimindenver]

400 watts is a comfortable fit for 30a. So you will use two panels in series and two sets in parallel. That will give you the voltage for the MPPT to do its job while not being so high it affects your efficiency and create excess heat. You could run all four in series but make sure it won't exceed the controllers Voc limit. Unlike clipping amps, over voltage will kill the controller fast.

 

[frater secessus]

I suggest calling Morningstar and asking if the warranty will replace a unit that has been over paneled and stops functioning.

From this Morningstar PDF:

"Q2. Can I exceed the nominal wattage ratings of MPPT controllers? Will it void the warranty? 

You can size Morningstar’s MPPT controllers well above the Maximum Nominal Solar PV Input rating without damaging the controller and without the charging current exceeding the maximum output current rating. The controller can limit output current and will run at 100% of rated current output and not higher. The controller was designed with this power-shaving capability and when oversized it does not void the warranty. "  <-- emphasis added