Deep water... [RE-wrenches]

[Windy Dankoff, Dankoff Solar]

<x-flowed>Allan Sindelar <allan at positivenergy.com> said

Gary,
>You have a good grasp of the options available.  Sometimes you just can't
>get there from here. Being a SunRise fan for its simplicity and 
>efficiency here in the arid
>Southwest, I would try to back up to the big picture first.
>...
>
>I mentioned your question to Windy Dankoff ... He'll have better advice.


Thanks, Allan.  I would take your approach and question the water 
requirement. Assuming that Gary (being a qualified "wrench") has have 
already done that, I offer the following correction to the discussion 
so far:

Trace is overly conservative in sizing inverters to run pumps. Also, 
the mod-sine DR-series will require more energy than a sine inverter 
because the pump will run less efficiently. For a full discussion of 
the issue, see our web site:

http://www.dankoffsolar.com/reference/invertersizing.html

Explanation: Trace recommends that the inverter be sized to handle 
the locked rotor amps. However, the pump only draws so at the instant 
of start-up IF the power source can actually supply that much, and 
that's a maximum based on no voltage drop etc. It is NOT a 
specification of starting surge requirement. The pump motor 
manufacturer lists locked rotor amps for the purpose of specifying 
overload protection. The pump does NOT normally require that much 
current to start.

Trace does not acknowledge this, so they are overly conservative. Our 
information in the above article was gathered from field experience.

This is for your information. I am not implying that the Trace 
inverter is necessarily the best solution to this system design 
problem. If the customer needs so much water, then given the budget, 
you may need to simply concentrate on setting him up with the best 
possible generator-based system, with an eye to future adaptation.
-- 

	===========================

	From the solar powered office of
	     Windy Dankoff, President

	===========================

Dankoff Solar Products, Inc.

    Wholesale distributor of solar-electric equipment
    Manufacturer & distributor of solar water pumps

2810 Industrial Rd.
Santa Fe, NM  87505

(505) 473-3800
FAX  473-3830
E-mail:	  info at dankoffsolar.com

SEE OUR INFORMATIVE WEB SITE AT:

http://www.dankoffsolar.com

	===========================

	To contact Windy Dankoff directly:
	Most days I am at my home office
	e-mail:  windy at dankoffsolar.com
	   tel/fax:  (505) 466-0059
	   ~ amateur radio KE5HV ~

	===========================

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