www.TheDoItYourselfWorld.com

Hi,

I'm from canada and I enjoy your videos. I have 2 MPPT-60 myself and I've repaired one once.

In your last video I noticed that your Max Array Voltage was at 143V dangerously close to the limit of the MPPT-60 at 150V.

Believe me you don't want to blow a MPPT-60. A shorted output MOSFET will blow out the drivers (they are surface mounted) and the board will unrepairable. I already saw this happened and I have photos to prove it.

You'd be safer if you parallel strings of 3 panels instead of 4. However with more than 2 strings in parallel you'd need to fuse each string separately.

A nice tool to use: The morningstar string calculator - http://98.115.2.6/en/strings/calc.php" onclick="window.open(this.href);return false;

Hope that helps!

Best!

Thank you. Yes I plan to reduce the strings down to 3 solar panels in series. Two sets in parallel. Then have the other two 235 watt panels in parallel on a separate charge controller

Well done.

Now with your new charge controller, you should consider putting a fuse in series with each panel if you plan to parallel more than 2.

Don't bother if using only 2 panels. If one becomes shorted, it can handle the current that will rush in from the 2nd panel.

It won't handle the current from 3 parallel panels though, hence the necessity for fuses.

http://www.cafr.ebay.ca/itm/20122675872 ... EBIDX%3AIT


Also you can find on Ebay/Amazon DB9 (serial) to USB cable converter to interface with a PC. I use that to reflash the firmware.
You won't be able to use the web interface as there is none in the PWM controller but you would be able to use the proprietary
software (MSView I think).


Finally Morningstar sells a 'Meterbus network hub' to interface 2 charge controllers to a single meter like you already have.

Lastly a quick electrical rule. If you double the current in a wire, the mimimum required wire size AWG need to be decreased by 3
e.g. is you use 10 AWG and you plan to double the current you would need 7 AWG. If you double again (quadruple in total),
4 AWG would be required.

Hope that helps!

Take care and congrats on you new landlordship. I know how you feel!

Thanks for all the tips.