[RE-wrenches] Magnum and Pumps

[Drake]

This information helps greatly. I really appreciate all of your expert advice.

One other wild card in the installation is that 
the inverter is going to be AC coupled with an 
Enphase system. The Enphase system will 
contribute greatly to the overall power available 
in the protected loads panel. But, with Magnum's 
slow voltage response I'm not sure if the Enphase 
system will drop off line when the pump surges, 
or if the Enphase power will be available to help with the startup surge.

Any insights on this?

Thank you,

Drake



At 02:10 PM 7/2/2014, you 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 <<mailto:jason at fafcosolar.com>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 SzumlanskiÂ
>
>​Fafco Solar​
>
>
>
>On Wed, Jul 2, 2014 at 10:47 AM, Allan Sindelar 
><<mailto:allan at sindelarsolar.com>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
><mailto:allan at sindelarsolar.com>allan at sindelarsolar.com
>NABCEP Certified PV Installation Professional
>NABCEP Certified Technical Sales Professional
>New Mexico EE98J Journeyman Electrician
>Founder (Retired), Positive Energy, Inc.
><tel:505%20780-2738>505 780-2738 cell
>
>Â
>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
>><tel:740-448-7328>740-448-7328
>><http://athens-electric.com/>http://athens-electric.com/Â
>
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