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<div class="moz-cite-prefix">Allen,<br>
<br>
I agree with Kirpal's comments. In fact, because the 300-volt
breakers take up so much extra space, I'd stay with the
three-modules-in-series design even if using the Classic charge
controller; unless the PV array was so far away that you need the
extra voltage to reduce wiring losses. But, for the example you
are talking about with four modules in series you would want a
Classic 200 not the Classic 150 because the Classic 150 would goes
into non-operational hyper-Voc mode at 28°C (82°F), measured at
the cell. <br>
<br>
The fact that the FM charge controller will talk to the Mate has
advantages: 1) Only one temperature sensor is needed, 2) Voltage
adjustment for grid-tie mode, and 3) Synchronization of equalize,
absorb, and float modes. Not one of these is a significant enough
issue to merit choosing the FM, and suffering from it's lower
efficiency and poor MPPT tracking, over the Midnite Classic or
Morningstar TriStar MPPT charge controllers.<br>
<pre class="moz-signature" cols="72">Kent Osterberg
Blue Mountain Solar, Inc.
<a class="moz-txt-link-abbreviated" href="http://www.bluemountainsolar.com">www.bluemountainsolar.com</a>
</pre>
On 12/16/2012 10:51 AM, Kirpal Khalsa wrote:<br>
</div>
<blockquote
cite="mid:CAM5ziKc4wUL8-eeCge4_eZZ65o4=BUzPK20TjGbHNu-o6gne0Q@mail.gmail.com"
type="cite">Allan...indeed this is a limitation....and yes i agree
with you that a higher voltage charge controller would be a
welcome update to Outbacks line up.....Looking at the DPW top of
pole list, i would suggest to you a design using 15 255 watt
modules with the FM80 charge controller which would both meet your
total wattage requirements, would still only need one charge
controller, as well as conform to the 3 module multiplication
requirement....additionally it would require less
foundation/excavation work, but would in fact be a honker of an
array....just an idea! Locally in your area I know Focused Energy
has a good price and availability of the US made SolarWorld 255's
which we use often...
<div>
Good luck.</div>
<div>Kirpal<br>
<br>
<div class="gmail_quote">On Sun, Dec 16, 2012 at 10:41 AM, Allan
Sindelar <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:allan@positiveenergysolar.com"
target="_blank">allan@positiveenergysolar.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF"> Wrenches,<br>
Please tell me if I'm overlooking something, in what
appears to be a design weakness:<br>
<br>
I would like to use an Outback Radian system for a
standard GTBB system. In order to take full advantage of
the system's capabilities, I have to use all of Outback's
main components; in this case the FM60 or FM80 charge
controller. The problem is that the most common (and
lower-cost) modules today are 60-cell, meaning 20
Vnominal. Given the 150V DC hard maximum voltage limit of
the FM-series charge controller, in our cold climate I can
only use these 20V modules in 60 Vnominal series strings;
that is, in multiples of three modules. As the Radian is
(wisely) offered in 48V only, pairs of modules would
provide too low a voltage, and series strings of four
modules would exceed 150 Voc in cold weather. <br>
<br>
The base Midnite Classic 150 will safely operate to 198
VDC in this application, but it won't communicate with the
Mate3.<br>
<br>
Is this a fundamental design limitation in the Radian
system, suggesting that Outback is due for a controller
upgrade, or am I missing something obvious? It appears
that arrays and racks have to be sized in ~720-watt sets
of three-module series strings, which can be problematic
in some designs. In the design in question I would like to
use 16 240W modules on two 8-module pole-top racks (for
seasonal adjustability); nothing in sets of three meets
the customer's output and aesthetic needs. <br>
<br>
Any solutions would be welcome.<br>
Thank you,<br>
Allan<span class="HOEnZb"><font color="#888888"><br>
<div>-- <br>
<font face="Times New Roman, Times, serif"><b>Allan
Sindelar</b></font><br>
<small><a moz-do-not-send="true"
href="mailto:Allan@positiveenergysolar.com"
target="_blank"><font color="#000099"
face="Times New Roman, Times, serif"><u>Allan@positiveenergysolar.com</u></font></a></small><font
face="Times New Roman, Times, serif"><br>
<span style="font-size:10pt">NABCEP Certified
Photovoltaic Installer<br>
NABCEP Certified Technical Sales Professional<br>
New Mexico EE98J Journeyman Electrician<br>
Founder and Chief Technology Officer<br>
<b>Positive Energy, Inc.</b><br>
3209 Richards Lane (note new address)<br>
Santa Fe, New Mexico 87507<br>
<b><a moz-do-not-send="true"
href="tel:505%20424-1112"
value="+15054241112" target="_blank">505
424-1112</a></b><br>
<a moz-do-not-send="true"
href="http://www.positiveenergysolar.com/"
target="_blank"><u>www.positiveenergysolar.com</u></a></span></font>
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