[RE-wrenches] Long transmission line inductance and LED light flicker

[Jerry Shafer]

I have had this issue with hanging LED's and it was in the inverter
programming, I only had 2 SI installed. I can't recall what the program
issue was but it was easy to see
Jerry
On Feb 12, 2014 8:14 AM, "Exeltech" <exeltech at yahoo.com> wrote:

> Troy,
>
> Elsewhere in this thread, boB (Midnite) suggested connecting one of the
> problematic lights and dimmers directly at the inverter output.
>
> This is a very sound recommendation, and would immediately rule in .. or
> rule out the conductors (and related circuits) as an issue.
>
> Another Wrench suggested using an oscilloscope to check the waveform at
> the load end.  This too is excellent advice, and would be even more telling
> than connecting the lamps and dimmer directly at the inverter.  The 'scope
> will reveal the AC voltage AND a visual indication of any waveform
> distortion, either aspect of which could potentially cause the flicker you
> describe.
>
> If you don't have access to a 'scope, boB's comment about connecting at
> the inverter won't require any test equipment.
>
> At a minimum, set your DVM to record the voltage minimum; connect it the
> lamp circuit, and turn on the 1 kW load you described.  If the voltage is
> dropping notably, this too would introduce visible flicker.  The DVM method
> is less accurate than an oscilloscope, but better than nothing, and depends
> greatly on the quality (or not) of your DVM.
>
> The above aside, anything else would be strictly conjecture .. which we
> can do all day, and never be correct.
>
>
> Dan
>
>
>
> --------------------------------------------
> On Wed, 2/12/14, August Goers <august at luminalt.com> wrote:
>
>  Subject: Re: [RE-wrenches] Long transmission line inductance and LED
> light flicker
>  To: "RE-wrenches" <re-wrenches at lists.re-wrenches.org>
>  Date: Wednesday, February 12, 2014, 9:01 AM
>
>  Hi Troy,
>
> Have you double checked that your grounding systems both in the house and
> at the inverters/array are all up to snuff?
>
> Sorry I can't offer any help with the inductance issue.
>
> Best,
>
> August
>
>
>
> From: re-wrenches-bounces at lists.re-wrenches.org [mailto:
> re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Troy Harvey
> Sent: Tuesday, February 11, 2014 5:45 PM
> To: RE-wrenches
> Subject: Re: [RE-wrenches] Long transmission line inductance and LED light
> flicker
>
>
> Richard,
>
>
> The system configuration is:
> Approx 24.7kW of modules connected to:
>             2 x 9kW Sunnyboys
>             1 x 5kW Sunnyboys
>
> Plus
> 4 x 6kW sunnyislands, with 2 Parallel 48V Strings of (12 x 4V Surrettes )
> using 350MCM cable
>
>
>
> Wire
>
> The wire is about 1000 feet long 350 MCM in a "twisted" bundle to this
> outbuilding
>
> Conditions
>
> The conditions were during the day with full sun, so during the test there
> is approx. 47kW of available inverter pointed at only >15 amps (120V) of
> load(!).
>
> The steady state conditions was a few LED lights, maybe 60 watts worth,
> plus a handful of vampire loads, maybe 100-200 watts total. When a pure
> resistance load, like a 1000W curling iron was turned on the lights would
> flicker.
>
> Since the lights flickered from a resistive load, but didn't stay dim, I
> assumed it was from a reactive-phase issues due to the transient  turn-on -
> screwing with the LED dimmer circuits which are already doing a bit of
> magic to turn TRIAC waveforms into a DC constant current.
>
> thanks,
>
> Troy Harvey
> ---------------------
> Principal Engineer
> Heliocentric
> 801-453-9434
> taharvey at heliocentric.org
>
>
>
> _______________________________________________
> List sponsored by Home Power magazine
>
> List Address: RE-wrenches at lists.re-wrenches.org
>
> Change email address & settings:
> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>
> List-Archive:
> http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
>
> List rules & etiquette:
> www.re-wrenches.org/etiquette.htm
>
> Check out participant bios:
> www.members.re-wrenches.org
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20140213/23b4f77a/attachment-0004.html>