[RE-wrenches] Retrofit variable speed drive to old well pump?

[Dan Fink]

Allan - my understanding is that with a 2-wire pump, the start capacitor is
integrated into the pump housing, underwater. I've never dealt with a
2-wire pump either....my experience has been with start capacitors in
3-wire pumps being located conveniently above ground in the pump control
enclosure.

Dan Fink
Adjunct Professor of Solar Energy Technology, Ecotech Institute
IREC Certified Instructor™ for:
~ PV Installation Professional
~ Small Wind Installer
Executive Director, Buckville Energy
NABCEP Registered Continuing Education Providers™
970.672.4342



On Sat, Dec 10, 2016 at 3:02 PM, Allan Sindelar <allan at sindelarsolar.com>
wrote:

> Dan,
> I have never had to work with a two-wire pump, so I'm on shaky ground
> here, but I refer back to what I learned years ago from Windy. The third
> wire in a three-wire pump carries the starting surge from the capacitor. A
> two-wire pump lacks this, and thus gets its entire surge-under-load from
> the AC source. This will be intrinsically difficult for an inverter, as
> compared to grid. So Shasta's surge question below is relevant. I'd
> determine both instantaneous surge and voltage drop; it may be that the
> combination - of battery voltage leading to reduced AC from the Magnum,
> voltage drop on the wires, and simply using the Magnum - will keep it
> always problematic.
>
> Years ago, when Dankoff Solar Products was in its prime as a distributor,
> Phil U did a load capacity test on various inverters of the time, including
> the Magnum MS4024. It had remarkably strong surge capacity, but did this by
> allowing a much greater voltage drop - down to around 80 VAC, if I recall,
> on a 120 VAC inverter.
>
> You may be dealing with a structural issue, for which upgrading the pump
> may be the best solution.
> Allan
>
> *Allan Sindelar*
> allan at sindelarsolar.com
> NABCEP Certified PV Installation Professional
> NABCEP Certified Technical Sales Professional
> New Mexico EE98J Journeyman Electrician
> Founder (Retired), Positive Energy, Inc.
> *505 780-2738 <(505)%20780-2738> cell*
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20161210/21c18b16/attachment-0002.html>