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 âconcurrently, you may
experience issues. As long as your customer
understands the limitations and possibilities, you may be just fine.
Jason Szumlanski
âFafco Solarâ
[]
On Wed, Jul 2, 2014 at 11:00 AM, Jason
Szumlanski <<mailto:ja...@fafcosolar.com>ja...@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
âFafco Solarâ
On Wed, Jul 2, 2014 at 10:47 AM, Allan Sindelar
<<mailto:al...@sindelarsolar.com>al...@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:al...@sindelarsolar.com>al...@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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