<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Hello Jeff,<div class=""><br class=""></div><div class="">Why mess with the grids unreliable and potentially harmful power. Go with your question 2\u2026. using the power inverters full time with no AC input, no transfer switch. You will need a power supply/battery charger large enough to power the loads through the inverter and maintain the battery at 100%. Protect the PS with the appropriate AC surge or LV protection. With this setup your AC power is always on with no brownouts or loss of power. <div class=""><div style="color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div class=""><br style="orphans: 2; widows: 2;" class=""><span style="orphans: 2; widows: 2;" class="">Larry Crutcher</span><br style="orphans: 2; widows: 2;" class=""><span style="orphans: 2; widows: 2;" class="">Starlight Solar Power Systems</span><br style="orphans: 2; widows: 2;" class=""></div></div></div><br class="Apple-interchange-newline"></div><br class="Apple-interchange-newline" style="color: rgb(0, 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;"><br class="Apple-interchange-newline">
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<br class=""><div><div class="">On Mar 13, 2020, at 12:02 PM, Jeff Clearwater <<a href="mailto:jeffc@villagepowerdesign.com" class="">jeffc@villagepowerdesign.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class="">
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Good Day Esteemed Wrenchers,<br class="">
<br class="">
So we are doing more work in developing countries where the grid is
super unreliable but on for some hours almost daily.<br class="">
<br class="">
So let's say we have a grid that's on 9 AM - 11 AM and 4 PM - 7 PM each
day but often browns-out during those hours and comes on and off during
those hours. 230 VAC voltage can drop to 160-180 periodically or go
above 260 in spikes.<br class="">
<br class="">
The present practice in many of these situations is for battery based
system designers/installers is to set up an off-grid system in parallel
to the mains but not relying on them - so the grid AC IN is not
connected. They just install a transfer switch and manually switch or
they wire a critical loads panel to the solar.<br class="">
<br class="">
This avoids constant switching and nuisance shut-downs from the battery
inverter and protects it from burning out trying to handle the grid.<br class="">
<br class="">
<span style="font-weight: bold;" class="">MY QUESTION:</span><br class="">
<br class="">
I'm wondering what we can do to use the grid when it is up for
opportunity charging of the batteries while at the same time not
subjecting our nice new battery inverters to constant brown-out tripping
and possibly long term damage.<br class="">
<br class="">
<span style="font-weight: bold;" class="">So question #1 </span>- Is anyone
using existing battery inverters but succesfully navigating such a grid
variablity settings such that you are able to take advantage of the grid
even if browning out often?<br class="">
<br class="">
<span style="font-weight: bold;" class="">or question #2</span> - Can we add
some sort of high Voltage and Frequency tolerant battery charger to the
system - keep the battery inverter/charger off grid - but charge the
batteries from something able to handle the wonky grid without
constantly nuisance charging or burning itself up?<br class="">
<br class="">
Your thoughts and wisdom I await!!!<br class="">
<br class="">
Best,<br class="">
<br class="">
Jeff<br class="">
<br class="">
<br class="">
<div class="moz-signature">-- <br class=""><span class="">~~~~~~~~~~~<br class="">
</span>
<div class="moz-signature">
<span class="">Jeff Clearwater</span><span class=""><span class=""><br class="">
</span>Village Power Design<br class="">
</span><span class=""><span class=""><span class=""><a href="https://www.linkedin.com/in/jeff-clearwater-0622a312/" class="">linkedin</a>
</span></span></span><br class="">
<span class=""><span class=""><a href="http://www.villagepowerdesign.com/" class="">www.villagepowerdesign.com</a></span><br class="">
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