<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div dir="ltr"></div><div dir="ltr">Hi Dave</div><div dir="ltr">It might be that the utility transformer is where the extra voltage rise is coming from?</div><div dir="ltr"><br></div><div dir="ltr">Jay</div><div dir="ltr"><br></div><div dir="ltr"><br></div><div dir="ltr"><br><blockquote type="cite">On Feb 23, 2023, at 10:03 AM, Dave Tedeyan via RE-wrenches <re-wrenches@lists.re-wrenches.org> wrote:<br><br></blockquote></div><blockquote type="cite"><div dir="ltr"><div dir="ltr">Hi All,<div><br></div><div>I've got a customer who is having issues with high voltage at their house. This first became an issue after installing 23.1kw of AC solar output. They have some GREE heat pumps which have been having some failures. The heat pump people are saying that the problem is that the voltage is above 252V. </div><div><br></div><div>The grid voltage was measured at 246V with the solar off, and 260V with the solar cranking. The inverters are within 10' of the MSP where there is a line side connection. Then there is 4/0 AL cable which has to go roughly 175' before it reaches the transformer. At 246V and 92A, there should only be about a 3.6V rise, or maybe 4V including the wire from the inverters to the combiner to the MSP. Yet somehow there is about 14V of rise. </div><div><br></div><div>The service entrance cable is buried. It is in conduit where it goes into and out of the ground, but I have no idea whether there is conduit for most of the run underground. Maybe there is a nick in the cable underground which has caused corrosion? Does anyone have any ideas of how to find the cause of the increased resistance? I should go back out there with an IR camera to check the connections that I can at least get to in the house. </div><div><br></div><div>I have suggested that they install a buck/boost transformer on the heat pump circuits to bring down the voltage a little bit. But they are also concerned about the high voltage causing issues with other electrical appliances in the house. Does anyone have any anecdata to show whether there are other hidden issues if the house is at 260V during times of high solar production?</div><div><br></div><div>Thanks!</div><div>-Dave<br><div><div><br></div>-- <br><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div dir="ltr"></div></div></div></div><div dir="ltr"><table cellpadding="0" cellspacing="0" style="border-spacing:0px;border-collapse:collapse;color:rgb(68,68,68);width:525px;font-size:11pt;font-family:Arial,sans-serif"><tbody><tr><td width="125" valign="top" rowspan="6" style="font-family:Arial,sans-serif;padding:0px 10px 0px 0px;font-size:10pt;border-right:1px solid rgb(236,189,0);width:125px;vertical-align:top"><a href="https://www.sungineersolar.com/" style="color:rgb(51,122,183);background-color:transparent" target="_blank"><img border="0" alt="Logo" width="105" src="https://sungineersolar.com/wp-content/uploads/2019/08/Logo-Image-Only-1.png" style="border:0px;vertical-align:middle;width:105px;height:auto" data-unique-identifier=""></a></td><td style="padding:0px 0px 0px 10px"><table cellpadding="0" cellspacing="0" style="border-spacing:0px;border-collapse:collapse;background-color:transparent"><tbody><tr><td valign="top" style="font-family:Arial,sans-serif;padding:0px 0px 5px 10px;width:400px;vertical-align:top"><span style="color:rgb(236,189,0);font-size:11pt;font-weight:700">Dave Tedeyan, P.E.<br></span><span style="font-size:11pt;font-weight:700"><font color="#ecbd00">Owner | Sungineer Solar</font><br></span></td></tr><tr><td valign="top" style="font-family:Arial,sans-serif;padding:5px 0px 5px 10px;font-size:10pt;vertical-align:top;line-height:17px"><span style="color:rgb(236,189,0)"><span style="font-weight:700">p: </span></span><span style="font-size:13.3333px"><span style="font-size:10pt;color:rgb(0,0,0)">he | him | his</span></span><span style="color:rgb(236,189,0)"><span style="font-weight:700"><br>a: </span></span><span style="font-size:10pt;color:rgb(0,0,0)">1653 Slaterville Rd.</span> <span style="font-size:10pt;color:rgb(0,0,0)">| Ithaca, NY 14850</span><br><span style="color:rgb(236,189,0)"><span style="font-weight:700">w:</span></span><a href="http://www.sungineersolar.com/" rel="noopener" style="color:rgb(51,122,183);background-color:transparent" target="_blank"><span style="font-size:10pt;color:rgb(0,0,0)"> www.sungineersolar.com</span></a><br><span style="color:rgb(236,189,0)"><span style="font-weight:700">c:</span></span><span style="font-size:10pt;color:rgb(0,0,0)"> (607) 288-2898</span></td></tr></tbody></table></td></tr></tbody></table></div></div></div></div></div></div></div>
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