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Wrenches,<br>
What are you using when you need a shunt larger than the standard
500A/50mV?<br>
<br>
The application: four Sunny Islands and a Radian in a large grid-tie
with backup system. Total current flow through B- is rated 850A
(using 125A SI DC breakers) or 1,050A (using 175A DC breakers) on a
single large battery bank. Given uncertain continuous amperage, I
should use a 1,000A shunt or even a 1,200A shunt, as Deltec
recommends never exceeding 67% of a shunt's current rating for long.
Deltec makes both; see <a class="moz-txt-link-freetext" href="http://www.deltecco.com/MKC-DC.html">http://www.deltecco.com/MKC-DC.html</a>. The
shunt will be installed inside of a Nottagutter-8, with a Midnite
shunt bus on each side. The shunt will be used with the Sunny Island
master to control overall SOC and charging parameters; there's no
plan for a Tri-Metric in this system, as a Sunny Webbox will handle
online monitoring per the customer's wishes.<br>
<br>
The 1,000 and 1,200A series MKC Deltec shunts are the same physical
dimensions as the common 500A/50mV units. However, the larger units
are still 50mV. Ralph Heisey of Bogart Engineering, in his
"Information on Shunts" reference article
(<a class="moz-txt-link-freetext" href="http://www.deltecco.com/MKC-DC.html">http://www.deltecco.com/MKC-DC.html</a>), tells us to match the ratio
of voltage drop to current - that is, just as a 500A shunt drops
50mV, a larger shunt with 1,000A flowing through it should drop
100mV. But all of the larger Deltec shunts are still rated 50mV.<br>
<br>
Who has done this and resolved the issue? What shunt did you use?<br>
<br>
Thank you,<br>
Allan <br>
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<font face="Times New Roman, Times, serif"><b>Allan Sindelar</b></font><br>
<small><a href="mailto:Allan@positiveenergysolar.com"><font
color="#000099" face="Times New Roman, Times, serif"><u>Allan@positiveenergysolar.com</u></font></a></small><font
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<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>505 424-1112</b><br>
<a href="http://www.positiveenergysolar.com/" target="_blank"><u>www.positiveenergysolar.com</u></a><o:p></o:p></span></font>
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