[RE-wrenches] Conext SW4048 not charging from generator

[Ray]

Definitely the generator.  Harbor Freight?  4 kW into a 4 kW charger?  
What's the altitude?   I believe that 4 kW generator is actually only 
3.5 kW continuous rated.   By the time you derate for altitude, and then 
account for the generator not being built to be a prime power unit, its 
probably reasonable to derate it 50%.  Then yet another thing,  those 
gennies are 240/120 so you only get half the rated power at 120 vac, and 
it unbalances the load on the generator.  Is that Conext 240/ 120 or 
just 120vac ?

Its just going to be a head ache for everyone until they buy something 
much better.  They really need something in the 6.5 kW to 9 kW range, 
and 240 to 120 transformer if the Conext is not the 240/120 model, so 
that the generator is loaded evenly.

Ray Walters
Remote Solar
303 505-8760

On 12/15/20 1:57 PM, Sindelar Solar wrote:
>
> Dave,
>
> I would first suspect the generator, not the inverter. Check its 
> output voltage and Hz under load. If it's overloading, either (or 
> both) voltage and frequency will drop below the acceptable range and 
> the inverter will unlatch its input relays, wait for a bit, relatch 
> and ramp up input amps until it again overloads and the cycle repeats. 
> You may reduce either (or both) charging amps and overall input amps, 
> broaden the frequency and minimum voltage acceptance ranges (I don't 
> recommend this), adjust the AC output voltage of the generator, or 
> advise them to get a better gennie.
>
> Allan
>
> On 12/15/2020 11:14 AM, Dave Tedeyan wrote:
>> Hi All,
>>
>> I am going to service a system where the homeowner is telling me that 
>> their Conext SW4048 had been working fine for 14 months, and then all 
>> of a sudden recently stopped being able to charge the batteries from 
>> the generator. It is an off grid system.
>>
>> The inverter would start charging the batteries, but then about a 
>> minute later they would hear a relay click and the charging would 
>> stop. Then it would just keep cycling. If they turned everything off 
>> for a while, they could then turn it back on and charge for maybe 10 
>> minutes before it would start cycling. They just have a crappy 4kw 
>> generator from Harbor Freight.
>>
>> I have not laid my own eyes on it yet, but will be there in the next 
>> day or two. Just wondering if anyone has experienced these symptoms 
>> and have a good idea of what to look for first.
>>
>> Thanks!
>> -Dave
>>
>> *Dave Tedeyan, PE*
>> Senior Engineer | Taitem Engineering, PC
>>
>> 110 South Albany Street | Ithaca, NY 14850
>> o. _607.277.1118 x121_  f. 607.277.2119
>> www.taitem.com <http://www.taitem.com>
>>
>> Solar •Sustainability • Energy • Design
>> Certified B-Corporation since 2013
>>
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> -- 
>
> *Allan Sindelar*
> allan at sindelarsolar.com <mailto:allan at sindelarsolar.com>
> NABCEP Certified PV Installation Professional
> New Mexico EE98J Journeyman Electrician
> Founder (Retired), Positive Energy, Inc.
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>
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