1.5 HP well pump [RE-wrenches]

[Travis Creswell, Ozark Solar]

Hello Todd,

I'm kind of surprised they won't start it. 

What's the starting and running amps?  This is a three wire pump, right?  It
should say right on the box what the starting and running amps is supposed
to be.  What's the battery bank dipping down to?  A few bad batteries could
really pull the bank down.  I've seen that several times.  And see if you
can't talk them into eliminating a few of those parallel strings.

Are the battery cables already 4/0?  When it's close to working, the
shortest and largest battery cables possible can really help with surge
problems.  I did a lot of playing around with this one time to get too small
of an inverter to start an AC unit for an RV.

What's the pressure switch set at?  If it's a 40/60 you might solve the
problem most of the time by changing out to a 20/40.

What about using the 240v well pump to fill atmospheric storage tank?  Then
using a small pump (12 volt DC?) for pressure?  You could prove if this
would work by testing to see how reliably the pump would start when the
pressure is 0 psi.  Turn the well breaker off - then open a tap until the
water stops running - turn the breaker back on, etc.

Good Luck,

Travis Creswell

-----------------
From: Todd Cory, Mt. Shasta Energy Services toddcory at finestplanet.com
Date: Sun, 07 Aug 2005 08:55:45 -0700
To: RE-wrenches at topica.com
Subject: 1.5 HP well pump [RE-wrenches]

Wrenches,

I inherited a poorly designed off grid system I am working on. It has a
stacked (240 volt) pair of DR1512 inverters fed by 12 L-16H batteries
(12 volts at 2500 a/h!!) trying to start a 1.5 HP well pump! The
inverters amazingly can occasionally start the pump when the batteries
are fully charged, but you know this has got to be a struggle for them.

I recall at one time someone saying increasing the capacitance of the
starting capacitor would ease the starting. It has a 240 volt 120 MFD
one now. What would people suggest (other than larger inverters) to make
this pump start reliably? Doesn't someone make a soft start control for
a well pump?

Thanks,

Todd