Outback generator support [WAS Advice sought for large off grid PV system;

[Davis Terrell]

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The FX will back off charging when passing through down to 5A AC (per 
inverter I think), but if your loads + 5A > the generator CB rating then 
your out of luck.   (page 51 of the FX manual)



-- 
Davis Terrell
Bright Earth Solar
(802) 492-2273 / brightearthsolar.com

Jeff Wongstrom wrote:
>
>
> Thanks Allan, I am an Outback fan and appreciate the constructive 
> criticism.
>
> I have this issue in an Outback system that originally had a single 
> VFX 3524 and 800ah battery which had no problem with tripping the 
> breakers of a 6.5KW Onan full output 120VAC.  When a second inverter 
> was added the generator breakers started to trip during the usual 
> laundry and vacuuming routine.  The 'solution' has been to drop the 
> second charger out by turning down the charge rate.  Unfortunately, 
> this drops the charge rate back to less than C/10 as a single charger 
> does not put out more than 70a.  We do a lot of winter generator 
> charging in NW Montana and do not mind hitting the batteries with C/5.
>
> I had thought that the charger would back off and allow the generator 
> to power loads without tripping gen breakers by limiting generator 
> input with AC2/GEN INPUT LIMIT.  Is this the same as 'the inverter 
> won't limit the pass-through load' ?
>
> Jeff Wongstrom
> NABCEP Certified Solar Installer
> Thirsty Lake Solar
> 406-889-5324
>
>
> On Apr 1, 2007, at 11:22 PM, Allan Sindelar wrote:
>
>>
>> No, Outback doesn't have generator support, at least not yet.
>>
>> The lack of generator support is a real issue. Somehow I just hadn't
>> realized the consequence of this, even after four years of working 
>> with FX
>> inverters. So I am calling attention to this now so others don't make 
>> the
>> same mistake.
>>
>> You can set the charge rate for the inverter, but you can't size the
>> inverter to optimize generator charging. This is because the inverter 
>> won't
>> limit the pass-through load. Outback suggests about 50% overcapacity 
>> beyond
>> what is necessary for charging.
>>
>> At our elevation range, a 3kW inverter-generator will put out around 
>> 18-19A
>> AC continuous, which is ideally suited for charging with one Outback, 
>> which
>> draws 19A maximum for charging purposes. However, if charging is set 
>> at this
>> level, there is no headroom for additional pass-through loads.
>>
>> The Yamaha 3kW inverter-generator will just lug, I have learned, 
>> until the
>> load is reduced. But the 3kW Honda inverter-generator will trip its 
>> output
>> breaker, which requires manual restart of the gennie.
>>
>> I understand that Outback is working on this obvious shortcoming. My 
>> hope is
>> that it will be available as a field upgrade, at least for existing 
>> non-GT
>> models.
>>
>> For now, on the one single-FX off-grid system that has an existing 3kW
>> Honda, we instructed the customer to turn off the main AC load 
>> breaker when
>> charging from the generator. It's a less than satisfactory solution, 
>> but so
>> is arbitrarily turning down the charge rate.
>>
>> Be forewarned, and avoid my mistake.
>>
>> Allan at Positive Energy
>>
>> ----- Original Message -----
>> From: "William Miller" <wrmiller at charter.net>
>> Sent: Thursday, March 29, 2007 9:48 AM
>>>
>>> Outback has generator support?  That is news to me!  When did this 
>>> occur?
>>>
>>> William Miller
>>>
>>>
>>> At 08:53 PM 3/28/2007, you wrote:
>>>
>>>> Outback and xantrex can support generator power, I
>>>> have a 3 phase support system that was originally to
>>>> be 55kW, and I found it to be cost effective up to the
>>>> 55 kW.  Also Outback, and Xantrex, and SMA have
>>>> products that can generator support and inverter
>>>> support.
>>>>
>>>> What is wrong with using transformers?
>>>>
>>>> Darryl
>>
>
>
> -- 
> [Non-text portions of this message have been removed]
>
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