<html><head></head><body bgcolor="#FFFFFF"><div>Darryl, OutBack makes GFDI in single, double and quad pole flavors: 80 Amps per pole, 1/2 Amp between the ground and grounded conductor. <br><br>The current method of ground fault protection is an imperfect beast, absolutely. However, it's been the industry standard and both the Code and standards have been written, interpreted and enforced in a manner that left installers and manufacturers little option. Like Kent, as an installer I never felt comfortable installing a device that, in a battery system, disabled the return fault current bond while leaving the inverter and DC loads operating. However, I want to call out and take exception to one of Kent's comments -- when there is a ground fault and the GF device lifts the bond, no metal object should be considered safe, no matter how securely you've grounded the array and all objects. By definition, all grounded surfaces which are normally at zero potential to ground should be considered as potentially energized when the system is indicating a fault. Think rattlesnake, loaded gun, whatever keeps your crew attentive and focused. </div><div><br></div><div>I think (but have no proof) that much of what passes as unusual or inexplicable behavior with PV arrays and ground faults resides in first-fault failures in the grounded conductors of PV arrays, to which current GFDI methods are blind. </div><div><br></div><div>I think the real solution will be when we as an industry transition to a more advanced method of GFDI, similar to what Europe does and what Bill Brooks and others are advocating. It's a better way. </div><div><br></div><div>Phil<br><br><div><br></div></div><div><br>On Apr 18, 2012, at 4:41 PM, Darryl Thayer <<a href="mailto:daryl_solar@yahoo.com">daryl_solar@yahoo.com</a>> wrote:<br><br></div><div></div><blockquote type="cite"><div><div style="color:#000; background-color:#fff; font-family:arial, helvetica, sans-serif;font-size:12pt"><div><span>Bob do you know of a 4x80 GFDI breaker? Midnight has a 2X80 correct? and Outback has a 2X80 </span></div><div><span>Wire size use the tap rule, 10 feet 10% of wire size. </span></div><div><br></div> <div style="font-family: arial, helvetica, sans-serif; font-size: 12pt;"> <div style="font-family: times new roman, new york, times, serif; font-size: 12pt;"> <div dir="ltr"> <font size="2" face="Arial"> <div style="margin: 5px 0px; padding: 0px; border: 1px solid rgb(204, 204, 204); height: 0px; line-height: 0; font-size: 0px;" class="hr" contenteditable="false" readonly="true"></div> <b><span style="font-weight: bold;">From:</span></b> "<a href="mailto:boB@midnitesolar.com">boB@midnitesolar.com</a>" <<a href="mailto:boB@midnitesolar.com">boB@midnitesolar.com</a>><br> <b><span style="font-weight: bold;">To:</span></b> RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org">re-wrenches@lists.re-wrenches.org</a>>
<br> <b><span style="font-weight: bold;">Sent:</span></b> Wednesday, April 18, 2012 5:08 PM<br> <b><span style="font-weight: bold;">Subject:</span></b> Re: [RE-wrenches] GFP and multiple charge controllers<br> </font> </div> <br>
<div id="yiv406557911">
<div>
<font face="Courier New, Courier, monospace"><br>
A lot of good replies have come by here but here goes another
one...<br>
<br>
The GFP cannot be used for dual purpose as a disconnect for
battery<br>
or PV input and y</font><font face="Courier New, Courier,
monospace"><span style="color: rgb(31, 73, 125);"><font color="#330033">ou</font>
<font color="#330033">are</font> <font color="#330033">not
allowed</font> <font color="#330033">to</font> <font color="#330033">un-ground</font> <font color="#330033">the
system by turning<br>
off the DC input or output breaker.</font></span></font><br>
<font face="Courier New, Courier, monospace"><br>
4 AWG should be fine for 80 amps. If you need/want to use smaller
wire<br>
than that required for an 80 amp GFP, MidNite makes a 63 amp GFP.<br>
<br>
boB<br>
<br>
<br>
<br>
<br>
On 4/17/2012 6:42 PM, William Miller wrote:<br>
</font>
<blockquote type="cite"><font face="Courier New, Courier, monospace">
Friends:<br>
<br>
Here is a related problem: If we use an 80 amp GFD (ground
fault
detection) breaker, even for a very small array, we have to use
3AWG CU
wire from the battery buss to the breaker and from the breaker
to the FM
or MX60. This seems like a big hassle for 5 or 10 amps of
charging. A variety of sizes of GFD breakers would be
helpful.<br>
<br>
Here is a bigger problem: GFD breakers don't really work. All
they do is turn off the charge function in hopes that someone
will find
the problem. In the meantime, the negative-to-ground bond is
removed and module mounting framework could be energized. PV
GFD
breakers are completely different from standard AC GFDI (ground
fault
detection and interruption) receptacles and circuit breakers.
The
AC versions interrupt power upstream, the PV versions interrupt
power
<i>downstream</i> from the fault.<br>
<br>
See:
<a href="http://millersolar.com/MillerSolar/case_studies/ground_fauilt/_ground_fault.html">http://millersolar.com/MillerSolar/case_studies/ground_fauilt/_ground_fault.html</a>
for some musings on the subject.<br>
<br>
As they say on TV: "There had to be a better way!"<br>
<br>
William Miller<br>
<br>
<br>
<br>
At 05:54 PM 4/17/2012, Kent Osterberg wrote:</font>
<font face="Courier New, Courier, monospace"><br>
</font>
<blockquote class="yiv406557911cite" cite="" type="cite"><font face="Courier
New, Courier, monospace">Nathan,<br>
<br>
I don't think anyone makes a 100-amp PV GFP. The panel mount
breaker model that's being used for the PV GFP doesn't include
a 100-amp breaker.</font>
<font face="Courier New, Courier, monospace"><br>
<br>
The Classic has a built-in GFP so you shouldn't need an
external GFP for it. You will need to add a GFP for the FM60 -
a single 80-amp GFP would work.<br>
<br>
You can use the dual 80-amp GFP and shut down both PV arrays
at the same time if the GFP is wired to disconnect the PV
array from the charge controller input. That's where Outback's
instructions used to show the GFP, and it is a better place
for it than on the charge controller output anyway. Midnite's
instructions show the GFP on the charge controller input, but
their 80-amp GFP is a single.<br>
<br>
</font>
<pre><font face="Courier New, Courier, monospace">Kent Osterberg
Blue Mountain Solar, Inc.
<a href="http://www.bluemountainsolar.com" rel="nofollow" target="_blank">www.bluemountainsolar.com</a>
</font></pre>
<font face="Courier New, Courier, monospace"><br>
On 4/17/2012 11:08 AM, Nathan Stumpff wrote: <br>
</font>
<blockquote class="yiv406557911cite" cite="" type="cite"><font face="Courier
New, Courier, monospace">Wrenches,<br>
<br>
In a job coming up I have a customer with an existing FM60
controller, 520 watt (!!) array. We are doing a ton of
work, including adding a 4 kW solar array with Classic 150
charge controller. I am trying to figure out how to handle
the GFP.<br>
<br>
For the Classic, I need a 90 or 100 A output breaker
minimum. 80 A is not an option. The OutBack dual GFP is 80
A, and so it not an option.<br>
<br>
Is there a 100 A GFP breaker assembly I have just never
seen? Is there a way to use the Classic’s GFP to run an
external relay via AUX (to trip the FM60 output breaker at
the same time)? Any ideas?<br>
<br>
Thanks,<br>
-Nathan<br>
<br>
Nathan J. Stumpff - Arctic Sun, LLC<br>
NABCEP Ceritified PV Installer #091209-175<br>
<a href="mailto:nathan@arcticsun-llc.com" rel="nofollow" target="_blank" ymailto="mailto:nathan@arcticsun-llc.com">nathan@arcticsun-llc.com</a></font>
<font face="Courier New, Courier, monospace"><br>
Office: 907/457-1297<br>
</font>
</blockquote>
<font face="Courier New, Courier, monospace">_________<br>
</font></blockquote>
<font face="Courier New, Courier, monospace">
<div>
Voice :805-438-5600<br>
email: <a class="yiv406557911moz-txt-link-abbreviated" href="mailto:william@millersolar.com" rel="nofollow" target="_blank" ymailto="mailto:william@millersolar.com">william@millersolar.com</a><br>
<a href="http://millersolar.com/" rel="nofollow" target="_blank">http://millersolar.com<br>
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