<div dir="ltr">Hi Larry. We did this recently. We settled on a Square D 60A 600VDC disconnect feeding a Midnite Solar Transfer switch with 60A, 300VDC breakers. We put an engraved placard on the transfer switch instructing the customer to turn off the disconnect first then to operate the transfer switch and when the transfer either way is completed to turn on the disconnect again. . It could have worked without the disconnect but we felt that it was probably an abundance of caution to operate the transfer switch with PV disconnected. <div>Our application was switching from a Grundfos pump in the summer to a Fronius inverter in fall and the reverse in spring. . This was a seasonal transfer instead of daily transfer. Certainly not automated. But relatively fool proof and safe. </div><div>Good luck. </div></div><div class="gmail_extra"><br clear="all"><div><div class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr">Sunny Regards,<br>Kirpal Khalsa</div><div dir="ltr">Oregon LRT#25<br>NABCEP Certified PV Installation Professional<br>Oregon Solarworks LLC<br><a href="http://www.oregonsolarworks.com" target="_blank">www.oregonsolarworks.com</a><br>541-299-0402</div></div></div></div></div></div></div>
<br><div class="gmail_quote">On Thu, Feb 16, 2017 at 4:24 PM, Roy Rakobitsch <span dir="ltr"><<a href="mailto:windsine@gmail.com" target="_blank">windsine@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="auto">Arcing would only happen when disconnecting pump during sunny periods, why not disconnect at dusk? Connecting pump will not arc due to soft start. Not sure about that particular charge controller, but some controllers can use Aux relay logic to do this upon full SOC. The Midnite Classic comes to mind. Swithcing can be done with contactor.<div dir="auto">Just a thought. <br><br><div data-smartmail="gmail_signature" dir="auto"><br>Roy Rakobitsch<br>NABCEP Certified Small Wind Installer®<br>Certified Advanced Tower Climbing, Safety & Rescue<br>Wind/PV Design Engineer<br>Windsine LLC<br><a href="tel:(631)%20514-4166" value="+16315144166" target="_blank">631-514-4166</a><br><a href="http://www.windsine.org" target="_blank">www.windsine.org</a></div></div></div><div class="gmail_extra"><br><div class="gmail_quote"><div><div class="h5">On Feb 16, 2017 4:24 PM, "Starlight Solar Power Systems" <<a href="mailto:larry@starlightsolar.com" target="_blank">larry@starlightsolar.com</a>> wrote:<br type="attribution"></div></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div class="h5"><div style="word-wrap:break-word">Hello Wrenches,<div><br></div><div>A customer has 3250 Watt PV array @ 139Voc. The PV controller is Magnum PT100. He wants to install a Grundfos SQFlex pump and be able to switch the DC from the PV controller to run the pump directly. He would like to switch midday after the battery (48V) is at a high SoC.<div><br></div><div>I’m looking for a switching arrangement to do this without arcing since it will be used a few times each week. Any have a recommendation? <br><div>
<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;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;word-wrap:break-word"><div style="color:rgb(0,0,0);letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;word-wrap:break-word"><div style="color:rgb(0,0,0);letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;word-wrap:break-word"><span><br class="m_209654119535949398m_9074264266585012395Apple-interchange-newline">Thank you,</span><br><br><span>Larry Crutcher</span><br><span>Starlight Solar Power Systems</span><br><br></div><br class="m_209654119535949398m_9074264266585012395Apple-interchange-newline"></div><br class="m_209654119535949398m_9074264266585012395Apple-interchange-newline"></div><br class="m_209654119535949398m_9074264266585012395Apple-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;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px"><br class="m_209654119535949398m_9074264266585012395Apple-interchange-newline">
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