<div dir="auto">Hi i have a single phase motor at a old install that i replaced about 8 years ago. Would it help if i made some starting load surge measurments?</div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Jan 28, 2022, 11:52 PM Darryl Thayer <<a href="mailto:darylsolar1@gmail.com">darylsolar1@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div dir="ltr"><div class="gmail_default" style="font-family:times new roman,serif;font-size:large">Hi Chris, In the past, I was able to start a 5 hp pump motor using a VFD. , I can not remember the make, of the VFD but I think it was an ABB 7.5 or 10 HP connected to a single-phase motor. I started it on two Outback 3548s (or maybe 3024s). Now for the tricky part, I have done this several times over the years so I keep confusing the systems. you must power the VFD before starting the motor to charge the capacitors as the VFD will also have a loading surge.( one time on maybe 10 HP I did a homemade resistor) The VFD has a large capacitance and will have a surge. Most water pumps do not have a high zero-speed torque requirement, meaning low inertia, so you can use a slower ramp to speed. watch your speed as the VFD can Overspeed the motor increasing the load. The advantage of the VFD is it can run at a lower speed reducing the load on the inverter. I also think an Auto Transformer will balance the load between the inverters, but may not be necessary.</div><div class="gmail_default" style="font-family:times new roman,serif;font-size:large">Also be aware that starting surge is on the battery also, If your motor has aGH motor it can have a 4 to7 times the running loads on starting. NEC 430,7 I think. This can be well over 100 amps. The inverter will sag in voltage during startup but they may draw 400 or 500 amps from the battery. If my memory is correct the 10 HP VFD has the possibility of adding an extra capacitor which reduces AC starting draw.</div><div class="gmail_default" style="font-family:times new roman,serif;font-size:large">Sorry, this was so long, it was more than 20 years ago for me. </div><div class="gmail_default" style="font-family:times new roman,serif;font-size:large"><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Jan 28, 2022 at 10:46 AM Chris Sparadeo <<a href="mailto:sparadeo.chris@gmail.com" target="_blank" rel="noreferrer">sparadeo.chris@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr">Hi all,<div><br></div><div>I currently have an off-grid client that has a 120/240VAC 7.5 HP - 40A FLC single phase pool pump. Locked rotor current is around 110 A. I had initially (and naively) thought that two Sol Ark 12k units would be able to handle this load. Due to the lack of a transformer, the unit's just can't output the required inductive startup inrush. Now getting clarification from Sol Ark that max inductive HP output is 2.5 HP per unit. We had installed an amply sized SR35 soft starter, with no avail. The 20 kW generator can start the motor, but it is noticeably shaken with the intense load drop. </div><div><br></div><div>I am toying with the idea of installing a VFD and upgrading the pool pump to a three phase motor. Would make for a much smoother ramp and self start. The client is a bit hesitant to upgrade and would like to continue using their clunky, non-self starting single phase motor. </div><div><br></div><div>My other thought was to implement an autotransformer to add some copper to the equation and help the Sol Ark's get the job done. Has anyone had any experience with the Victron 100A autotransformer for both 120/240 input and output? </div><div><br></div><div>Any suggestions or relative experience would be greatly appreciated!</div><div><br></div><div>-Kindly,</div><div><br></div><div>-Chris</div><div><div><br></div>--<div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div><p style="color:rgb(0,0,0);margin:0in 0in 0.0001pt;line-height:1.25"><strong style="font-size:11pt;font-family:Arial,sans-serif;color:rgb(0,51,0)"><em>Chris Sparadeo </em></strong></p><p style="color:rgb(0,0,0);margin:0in 0in 0.0001pt;line-height:1.25"><strong style="font-size:11pt;font-family:Arial,sans-serif;color:rgb(0,51,0)"><em>NABCEP Certified PV Installation Professional </em></strong><em style="color:rgb(32,33,36)"><b><span style="font-family:Arial,sans-serif;color:rgb(0,51,0)"><font size="1">®</font></span><span style="font-size:11pt;font-family:Arial,sans-serif;color:rgb(0,51,0)"> </span></b></em><strong style="font-size:11pt;font-family:Arial,sans-serif;color:rgb(0,51,0)"><em># 042919-015652</em></strong></p><p style="color:rgb(0,0,0);margin:0in 0in 0.0001pt;line-height:1.25;font-family:Calibri,sans-serif"><strong style="font-size:11pt;color:rgb(0,51,0);font-family:Arial,sans-serif"><em>NABCEP Certified PV System Inspector </em></strong><em style="font-family:Arial,Helvetica,sans-serif;color:rgb(32,33,36)"><b><span style="font-family:Arial,sans-serif;color:rgb(0,51,0)"><font size="1">®</font></span></b></em><strong style="font-size:11pt;color:rgb(0,51,0);font-family:Arial,sans-serif"><em> # 052920-015652 </em></strong></p><p style="color:rgb(32,33,36);margin:0in 0in 0.0001pt;line-height:1.25"><font color="#003300" face="Arial, sans-serif"><span style="font-size:14.6667px"><b><i>State of Vermont Journeyman Electrician # EJ-07619</i></b></span></font></p></div><div></div></div></div></div></div></div></div>
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