[RE-wrenches] Magnum and Pumps

Wed Jul 2 12:15:29 PDT 2014

Even at 9600W, which is above the 5 second surge rating of the inverter,
we're looking at about 200A on the DC side, which would be a 1-hr rate on
an L-16 string. While that is high, it should not be an issue. Even at the
1ms surge of 16,800W, a 48 string of L16's should be able to handle that.

Jason Szumlanski

Fafco Solar

On Wed, Jul 2, 2014 at 2:35 PM, Roy Butler <roy at four-winds-energy.com>
wrote:

>  I haven't seen anyone mention the battery bank. If I understand
> correctly, there's a single string of sealed
> L16 batteries on this inverter. I have my doubts as to whether or not that
> bank can provide the high current
> the inverter needs to start this load.
>
> Roy Butler
> NABCEP Certified Solar PV Installer®
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>
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>
>
> On 7/2/2014 2:10 PM, Jason Szumlanski wrote:
>
>  To further qualify my statements, the inverter will start the pump
> without issue, but I should echo the warnings by others that if there are
> other loads present, especially other motor loads that could start
> concurrently, you may experience issues. As long as your customer
> understands the limitations and possibilities, you may be just fine.
>
>
>   Jason Szumlanski
>
>  Fafco Solar
>
>
>
> On Wed, Jul 2, 2014 at 11:00 AM, Jason Szumlanski <jason at fafcosolar.com>
> wrote:
>
>>  For what it's worth, I've run a single speed 1.5HP pool pump with a
>> MS4448PAE in a mobile application on a 38.4kWh battery bank (sixteen Rolls
>> S-530's). I have also run a 2.5HP Hayward EcoStar Variable Speed pool pump
>> at full RPM, but that startup current is likely less than you well pump.
>>
>>  I'm going to guess your 3/4HP well pump will be a breeze to start with
>> this inverter.
>>
>>
>>   Jason Szumlanski
>>
>>  Fafco Solar
>>
>>
>>
>>  On Wed, Jul 2, 2014 at 10:47 AM, Allan Sindelar <allan at sindelarsolar.com
>> > wrote:
>>
>>>  Drake,
>>> As a normal CYA, I'll always gently let a customer know that this (or
>>> any) particular combination of inverter and load sometimes proves
>>> incompatible, just in case the unexpected happens. (We once had a MS4448
>>> that would not reliably start and run a condensing boiler; a switch to a
>>> different boiler resolved the issue.)
>>>
>>> Having said that note of caution, I wouldn't give it any concern. 3/4 HP
>>> and 1 HP well pumps have never been an issue; I would expect 1.5 HP to be
>>> easy to run. At 2 HP I'd be asking these questions here.
>>>
>>> You might check that it's a 3-wire, capacitor-start motor, but nowadays
>>> nearly all are. Two-wire pumps (with no control box) can add 50% to the
>>> surge.
>>>
>>> The Magnum has a fairly poor voltage regulation response. Sometimes the
>>> AC voltage can drop to ~80 VAC momentarily. So you might also caution your
>>> customer that the lights may flicker when the pump starts. In our home we
>>> know whenever our Kenmore fridge turns on.
>>>
>>> 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*
>>>
>>>
>>>   On 7/2/2014 8:17 AM, Drake wrote:
>>>
>>>  Hello Wrenches,
>>>
>>> We are hoping to use a Magnum PAE 4448 to back up a household that
>>> includes a 3/4 HP deep well pump. There is about 120 feet of vertical rise
>>> and about 1000 feet of horizontal distance.
>>>
>>> I have been told that there is a correlation between the locked rotor
>>> current of a pump and the predictable ability of a specified inverter to
>>> power that pump.
>>>
>>> The plumber who installed the pump left no paperwork and retained no
>>> records of what pump he put in the hole last year. He could only say it was
>>> a 3/4 HP pump. We are therefore unable to obtain the manufacturer's
>>> nameplate specifications.
>>>
>>> The Magnum PAE 4448 has a 1 mS surge of 70 A (at 240 V) and a 100 MS
>>> surge of 40 A. According to the NEC Table 430.251(A), a 3/4 HP motor has a
>>> locked rotor current of 41.4 amps at 230 V.
>>>
>>> This inverter can surge at 35.4 A for 5 seconds. The specified battery
>>> bank will be 8 Full River  L-16 AGMs. Can anyone say if:
>>>
>>>    - Is there enough information to know if this setup will handle the
>>>    pump, and if so, will it?
>>>    - How can an inverter's ability to power a motor or pump be
>>>    calculated by knowing its locked rotor current? Which surge periods should
>>>    be compared to the locked rotor current?
>>>    - Does the surge current need to equal locked rotor. How long must
>>>    the inverter meet its required maximum surge?
>>>    - From experience with Magnums and pumps, does this seem like a good
>>>    combination?
>>>
>>>
>>> Thank you,
>>>
>>> Drake
>>>
>>> Drake Chamberlin
>>>
>>>
>>>
>>>
>>>
>>> *Athens Electric LLC OH License 44810 CO License 3773 NABCEP Certified
>>> Solar PV 740-448-7328 <740-448-7328> *http://athens-electric.com/
>>>
>>>
>
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