[RE-wrenches] two VFX3524's and a Franklin 3hp sub pump

Kurt Albershardt rewrench at sw-ei.com
Thu Jun 24 10:41:49 PDT 2010


Once you determine the real pump requirements (as others have mentioned, this is critical - IME particularly if the "well guy" sized and sold the pump) and if a larger than SQflex pump is needed, I have had good luck using VFDs to drive three-phase pumps with single phase power.  You can pay Franklin the big $$ for their system, but a commodity VFD from someone like Automation Direct will set you back about $100/HP and (up to 3 HP) will accept single phase input power.  This gets you sophisticated motor protection, programmable ramp soft starts, restart delays, and a plethora of input and output terminals for shutdown switches, PID sensor inputs, etc. and will allow you to create all manner of interesting system behavior.  Most also include a (software programmable) runtime limitation or alarm which can prevent  scenarios like Chris described below.  3-phase motors are more efficient anyway so I seriously doubt we will sell a traditional single phase pump or fan again.





On Jun 19, 2010, at 22:37 , frenergy wrote:
> Ray,
>  
>         Yes, thus my qualification:"seems to be pretty bombproof". 
>  
>         Also though, a deatil I left out which would have a major longevity impact on this tank shut-off/on set-up is that the pump supplying water to the tank only comes on once a day (ala digital timer), thus the tank valve, seal, float, rod, etc. are only cycled once/day.  The daily water consumption draw down is only about 15% of tank capacity, so we chose to pump water once a day.  I guess this scenario also acts as a safety for an event like the one you described, months of pumping for naught do to failed float shaft.
>  
>  
> Bill
> Feather River Solar Electric
> 4291 Nelson St.
> Taylorsville, CA  95983
> 530-284-7849/6544 fax
> ----- Original Message -----
> From: R Ray Walters
> To: RE-wrenches
> Sent: Thursday, June 17, 2010 8:10 AM
> Subject: Re: [RE-wrenches] two VFX3524's and a Franklin 3hp sub pump
> 
> Float valves too have been problematic. Seals wear and leak after several years, and just a couple of months ago, we had the brass shaft that connects the float to the valve break off. In this case the tank had an over flow that went into the septic. So nothing was damaged by the over filling, but no one knew that was happening either. We were called to troubleshoot a grid tie system that wasn't running the meter backwards, then the well pump guy came out, and then finally the plumber who had done the tank system. By then, the pump had run 24/7 at 10 gpm for a couple of months of fresh clean well water straight into the septic. Our customer's electric bill was in the hundreds of dollars.
> I wouldn't quite say they're bomb proof.
> 
> R. Walters
> ray at solarray.com
> Solar Engineer
> 
> 
> 
> 
> On Jun 16, 2010, at 10:32 PM, frenergy wrote:
> 
>> Chris,
>>  
>>         I've seen a bladder tank modulate the "shut-down" process in a up-the-hill gravity feed tank when using a (IMO) more reliable float valve rather than a float switch.  Watts model number 1250 is an example of a toilet tank method of stopping/starting flow to a tank.  With the bladder tank and a standard issue Sq D. pressure switch (in the vicinity of the wellhead) it seems to be a pretty bomb -proof set-up.
>>  
>> Bill Battagin
>>  
>> Feather River Solar Electric
>> 4291 Nelson St.
>> Taylorsville, CA  95983
>> 530-284-7849/6544 fax
>>  
>>  
>> ----- Original Message -----
>> From: Chris Worcester
>> To: Allan at positiveenergysolar.com ; 'RE-wrenches'
>> Sent: Wednesday, June 16, 2010 1:34 PM
>> Subject: Re: [RE-wrenches] two VFX3524's and a Franklin 3hp sub pump
>> 
>> Great ideas on load management to save the DC/AC system sizing. I haven’t spent time researching their need for this 3hp pump or age and all, but definitely worth looking at that side. Since it does pump to the 3000g gravity feed tank up the hill. What’s strange is there is still a bladder tank in the garage, possibly decommissioned when they added the gravity system.
>> Sincerely,
>> 
>> Chris Worcester
>> Solar Wind Works
>> NABCEP Certified PV Installer
>> Phone: 530-582-4503
>> Fax: 530-582-4603
>> www.solarwindworks.com
>> chris at solarwindworks.com
>> "Proven Energy Solutions"
>> From: re-wrenches-bounces at lists.re-wrenches.org [mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Allan Sindelar
>> Sent: Tuesday, June 15, 2010 8:48 PM
>> To: jryago at netscape.com; RE-wrenches
>> Subject: Re: [RE-wrenches] two VFX3524's and a Franklin 3hp sub pump
>> Chris,
>> We deal with deep wells routinely.
>> 
>> Recently we installed a GTWB system for a very enjoyable retired couple. Their needs included the goat milker, sheep barn, two freezers and a fridge, and irrigation well pump, with the system sized for continuous operation in the event of a long-term (i.e. permanent) loss of the grid. This was on one acre in the suburbs south of Albuquerque. We used an XW4548, as it was the only battery-based, 120/240, single-inverter, grid-tie unit available currently.
>> 
>> As part of the normal load-reduction process, we determined that the 2hp conventional well pump could be replaced with a 1hp soft-start SQ and have adequate head and flow for their sprinklers. Changing out the pump way more than paid for itself in the amount of inverter capacity we didn't need. 
>> 
>> I would encourage you to look at both of these related issues carefully as part of this situation: could a smaller pump meet the head and flow requirements of this site, and is a soft-start pump available? Usually, if an inverter or stack of them can't handle a big inductive load like a conventional pump, it's because of the starting surge. I suspect a smaller soft-start pump may be doable in your situation.
>> Allan
>> 
>> Allan Sindelar
>> Allan at positiveenergysolar.com
>> NABCEP Certified Photovoltaic Installer
>> EE98J Journeyman Electrician
>> Positive Energy, Inc.
>> 3201 Calle Marie
>> Santa Fe, New Mexico 87507
>> 505 424-1112
>> www.positiveenergysolar.com
>> 
>> Hello offgrid Wrenches,
>> I just inherited an off grid system with one VFX3524 inverter running the home loads, and a 17kW Guardian Generac they use for charging (through an X-240 back into the inverter) & to run their Franklin 3hp 240 VAC well pump, S. F. max amp 17.0 ( rated on its controller)
>> This is a really convoluted system as they have another 120/240 VAC Transformer to have the inverter talk to the 240 volt signal the gen set needs to see. Yikes.
>> So I am proposing to add a second inverter if it can run the well pump and eliminate the extra transformer. This will also reduce gen set run time in half while battery charging, a big plus with the nice 24V Hawker battery bank, 1020 AH at the 6 hour rate.
>> There aren’t any other unusual large AC loads in the home, just the fridge, washer, computer, and such. LPG for cooking, water heating, clothes dryer.
>> Thanks in advance for all ideas here!
>> Sincerely,
>> 
>> Chris Worcester
>> Solar Wind Works
>> NABCEP Certified PV Installer
>> Phone: 530-582-4503
>> Fax: 530-582-4603
>> www.solarwindworks.com
>> chris at solarwindworks.com
>> "Proven Energy Solutions"

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