[RE-wrenches] To stack or not to stack? Off-grid 240V

Wed Oct 30 11:19:08 PDT 2013

Hilton,

Magnum Energy also has a single 4400 VA model, the MS4448PAE, that operates 120/240 split phase. It can provide 8500 Watts for 5 seconds and 40 amps (line to line) for 100ms. This might start the 3HP motor load assuming it is 240 volt induction motor and not a capacitor start. Also assuming no other high loads are operating. See if you can find out (letter code on motor) or test for the LRA of the motor.

(Allan) Battery voltage dip is proportional to load/battery capacity. I install lots of Magnum product but I have not experienced voltage dip with large loads starting. Perhaps it was related to waveform and the CFL's. Magnum Energy products are designed and built in the uSA and have been the best and most reliable inverters that I have experienced so my vote is for Magnum.

Larry

On Oct 30, 2013, at 7:57 AM, Allan Sindelar <allan at positiveenergysolar.com> wrote:

Hilton,
Kevin's comments are well taken. To add a bit:

Magnum are exceptionally easy to set up and program. The user interface is well designed. A few issues to be aware of from my experience: 
- All of our Magnum-based off grid systems have been single inverter. At 4 kW, a single inverter may not be enough for that particular 3hp motor - best to CYA with the customer on the possible need for a stacked pair. 
- Magnum allows a pretty wide voltage dip to accomplish surge capacity, so when the saw starts, expect lights to flicker. Our CF bulbs flicker when the refrigerator starts.

Our trial with Apollo a couple of years ago was probably the single most negative experience with an inverter manufacturer of my career. Kevin's comment that the most basic programming required hooking up to a computer is accurate. The computer must have their proprietary software installed, and the hookup was necessary even to initiate an equalize charge from an AC source. We have several warranty replacement and takeout units on a shelf here, from two installations (including in my own home) where the equipment was replaced after being unable to get it to work reliably. Ultimately, Apollo agreed in writing to reimburse us for the cost to replace their equipment with another brand. They never came through. 

Allan

Allan Sindelar
Allan at positiveenergysolar.com
NABCEP Certified PV Installation Professional
NABCEP Certified Technical Sales Professional
New Mexico EE98J Journeyman Electrician
Founder, Positive Energy, Inc.
A Certified B CorporationTM
3209 Richards Lane
Santa Fe, New Mexico 87507
505 424-1112 office 780-2738 cell
www.positiveenergysolar.com

> -----Original Message-----
> From: re-wrenches-bounces at lists.re-wrenches.org [mailto:re-wrenches-bounces at lists.re-wrenches.org]On Behalf Of Hilton Dier III
> Sent: October 29, 2013 6:48 PM
> To: re-wrenches at lists.re-wrenches.org
> Subject: [RE-wrenches] To stack or not to stack? Off-grid 240V
> 
> Hello Wrenches,
> 
> I have an off-grid client with a 24V system and an old Xantrex SW4024. He wants 240VAC capability with enough oomph for sometimes making a cut with his 3 hp table saw without starting the generator.
> 
> I am looking at Apollo, Magnum, and Outback inverters. I'm most familiar with Outback. I have a couple of installations out there with stacked 3.6 kW Outbacks.
> 
> However, the Apollo marketing promises that their 3.2 kW inverter will start a 3 hp motor. Will it actually, and is this a good idea even if it can?
> 
> I'd appreciate hearing about your experiences with 240V Apollo units, stacked Magnums, and stacked Outbacks. I know from experience that the Outbacks require some hundreds of dollars of extra fittings and electronics to make a proper stacked installation. How about Magnum? Any comments on reliability?
> 
> Many Thanks,
> 
> Hilton 
>  -- 
> Hilton Dier III
> Renewable Energy Design
> Partner, Solar Gain LLC
> 453 East Hill Rd.
> Middlesex, VT 05602

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