Hi Chris I googled and a new 3phase motor is about $1000 and the vfd is about $500 maybe. Say $3000 for the upgrade?
Seems like the easiest to do, easier on the existing inverters, it’s the least expensive long term option. I don’t know what the transformer would provide as a fix because the pump is already 240? I’m not even going to ask if he actually needs a 7.5hp motor. Jay > On Jan 28, 2022, at 9:46 AM, Chris Sparadeo <sparadeo.ch...@gmail.com> wrote: > > > Hi all, > > 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. > > 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. > > 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? > > Any suggestions or relative experience would be greatly appreciated! > > -Kindly, > > -Chris > > -- > Chris Sparadeo > NABCEP Certified PV Installation Professional ® # 042919-015652 > NABCEP Certified PV System Inspector ® # 052920-015652 > State of Vermont Journeyman Electrician # EJ-07619 > _______________________________________________ > List sponsored by Redwood Alliance > > Pay optional member dues here: http://re-wrenches.org > > List Address: RE-wrenches@lists.re-wrenches.org > > Change listserver email address & settings: > http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org > > There are two list archives for searching. When one doesn't work, try the > other: > https://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/ > http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org > > List rules & etiquette: > http://www.re-wrenches.org/etiquette.htm > > Check out or update participant bios: > http://www.members.re-wrenches.org >
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