[RE-wrenches] Snow mitigation

[don energysolarnow.com via RE-wrenches]

Some time ago there was a post about SMA SunnyBoys that could send current back 
to the solar panels to melt off snow.
This was grid power; but maybe you can use genny or whatever solar power is 
generated to warm up the snowy panels, presuming some of them are uncovered.
Either that or set them steeper to shed the snow.
Don Barch
Energy Solar

Date: Sat, 9 Dec 2023 09:42:33 -0800
From: Bill Battagin 
To: offgridso...@sti.net, Wrenchlist

Subject: [RE-wrenches] Snow mitigation
Message-ID: <2755cb29-257c-427a-ab39-bc6c9c0cc...@psln.com>
Content-Type: text/plain; charset="utf-8"; Format="flowed"

I've been consulting and helping a friend with a mountaintop PV powered
radio system ~7,000' in the No.Sierras. We installed another array this
fall but at 60 degree tilt we're still having problems with snow
accumulation on the PVs, plus once the weather passes it stays too cold
to melt in the bright sun we need to get SOC back up.? Yes, there is
genny back-up, but that's no fun for a solar fanatic.

 ??? ??? ??? Some wrenches have done this kind of install I know, it
would be great to hear of ways to prevent snow from sticking?, ways to
shed it unattended, right? Laser from valley floor!

Thanks,

Bill

Feather River Solar Electric
Bill Battagin, owner
4291 Nelson St. (Shipping)
5575 Genesee Rd. (USPS, UPS)
Taylorsville, CA  95983
530-284-7849, 258-1641(cell)
CA. C10 Lic # 874049
Solar Powered since 1982
Home of the Sunny Side Up



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[RE-wrenches] Sol-Ark phantom loads

[don energysolarnow.com via RE-wrenches]

Just spent yesterday debugging a Sol-Ark 15 kW inverter phantom load weirdness.
With Work Mode set at Limited Power To Home it seemed to get a bit schizo, 
pulling around 6kW in from the grid on leg L1 and around 13 kW on the other L2 
leg, with 7kW of PV added. No house loads were involved. The monitoring called 
this a 13 kW load.
I measured something like 50 amps on L2 and neutral; 120 Volts on L1 and 125 
Volts on L2 at the house. My Fluke clamp-on amp meter does not say which way AC 
current is flowing. The utility meter showed it as  power coming in.
At the main meter panel about 150 ft away from the house the voltages were 
better balanced; probably due to proximity to the utility transformer. Those 
leg voltages were balanced when the inverter was shut down.
Oddly, this phantom loading decreased with decreasing PV production later in 
the day.
Working with Sol-Ark tech support we (of course) downloaded new firmware, then 
changed Work Mode to Limited Power To Load. After a couple of resets this had 
the effect of allowing the inverter to cover just the loads in the 
battery-backed subpanel; not those at the house main panel where the CT sensors 
are located. The phantom 13kW load has not recurred.
Has anyone seen an inverter try to mix import and export on different legs by 
creating phantom loads?

Don Barch
Energy Solar



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Re: [RE-wrenches] Inverter output fluctuations

[don energysolarnow.com via RE-wrenches]

Howie-
 it sounds like the XW+ is trying to curtail the Solar Edge by shifting 
frequency, and the loads don't like it.
When off-grid and batteries are charged there is no place for all that AC 
coupled solar power to go.
This is an issue windmill folks have too. The solution can be as simple as a 
dump load such as a water heater to absorb the excess energy.
Tell the customer to turn the hot tub up high, or something like that. Heat up 
a bathtub in a greenhouse and plant bananas.

DonBarch
Energy Solar

From: Howie Michaelson 
To: Dave Angelini , RE-wrenches

Subject: Re: [RE-wrenches] Inverter output fluctuations
Message-ID:

Content-Type: text/plain; charset="utf-8"

Hi,
I was finally able to get to the site with the light pulsating issue. It
turns out it is that it directly corresponds to the AC coupled SolarEdge
HDwave 6kW inverter.  Moreover, the pulsating gets stronger with higher
output of the SolarEdge inverter (as more sun pouches more current through
the inverter). And the hum of the XW+ very noticeably fluctuates in direct
proportion to light fluxuations. It affects all the lights in the house,
regardless of manufacturer, wattage or age. I did not have an oscilloscope,
but looking at the Hz, it does sag very slightly to 59.9 when the SolarEdge
is producing, down from a rock solid 60 Hz when the SE is not producing.
The output voltage does not change at all.  The fluctuations in both the
lights and the inverter hum immediately stops when the SolarEdge production
is shut off. So it is clearly some interaction between the 2 inverters
causing this issue.

Has anyone dealt with this issue before? Does anyone have any suggestions
for dealing with this, short of replacing the SolarEdge with a Schneider
high voltage Charge Controller?
Thanks,
Howie

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[RE-wrenches] AFCI tripping on SB 4000US-12

[don energysolarnow.com via RE-wrenches]

You should also check the AC wiring. AFCI is detected as radio frequency noise 
from some kind of arc fault. It can be either AC or DC arcing.
I had some AFCI tripping issues that turned out to be loose wiring at the AC 
connector inside the SunnyBoy. It was easily fixed by tightening the screws. 
Since this connector is much closer than the DC wiring it would take less 
faulting to set off the alarm.

Don Barch
Energy Solar

>Friends:
>
> We installed a bunch of Shell SQ-150-PC modules on a ground mount almost
> 20 years ago.  The original SB2500 inverters died so we upgraded to
> SB4000US-21 inverters.  We had some ground fault or AFCI issues a number of
> years ago so we replaced all homeruns with PV wire which resolved the
> problem.
>
> These panels have J-boxes which we interconnected with 1/2? NMLT.  The
> home runs are with PV wire with absolutely no splices and the inter-panel
> jumpers are THWN.
>
> Recently we started getting AFCI disturbances on one inverter.  We
> isolated the fault to one string.  We opened every pull box and panel J-box
> and all of the wiring looks dry, clean and tightly connected.  We inspected
> every panel front and back and see no hotspots or visible corrosion.
>
> I have a megger I have never used.  The homerun is kind of long so maybe
> it has insulation problems.  I could isolate the homerun and megger those
> leads.  I am researching if I can megger PV modules.  It looks like this is
> commonly done.  That looks like my next step.
>
> Does anyone have any ideas on what I should do next? I suppose I could
> start swapping each of the 10 modules in the problem string with panels in
> the non-problem strings, but that seems like a lot of work.
>
> Thanks in advance.
>
> William Miller
>
> Miller Solar
>
> 17395 Oak Road, Atascadero, CA 93422
>
> 805-438-5600
>
> www.millersolar.com
>
> CA Lic. 773985

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Re: [RE-wrenches] Envoy R replacement (Dave Tedayan)

[don energysolarnow.com via RE-wrenches]

Hi Dave
You can get a used Envoy-R to talk to the local microinverters, but you will 
not be able to reassign it to the new site. You will have to beg Enphase to do 
this for you. Sometimes this costs money if they think you are reassigning the 
whole system to a new owner.
But why bother? The Envoy-R was superseded by the Envoy-S that can do Wifi and 
talk to the app in AP mode as well.

Don Barch
Energy Solar




Message: 1
Date: Fri, 13 Jan 2023 13:20:25 -0500
From: Dave Tedeyan 
To: RE-wrenches 
Subject: [RE-wrenches] Envoy-R replacement
Message-ID:

Content-Type: text/plain; charset="utf-8"

Hi all,

Does anyone know if you can get any old used Envoy-R (the one in the
attached image) off ebay to replace a failed one? If the used one used to
be associated with another site, would there be issues with installing it
somewhere else?

Cheers,
Dave

--
[image: Logo] 
Dave Tedeyan, P.E.
Owner | Sungineer Solar
p: he | him | his
a: 1653 Slaterville Rd. | Ithaca, NY 14850
w: www.sungineersolar.com 

c: (607) 288-2898


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Re: [RE-wrenches] wire management on Qcell AC module

[don energysolarnow.com via RE-wrenches]

No you certainly cannot rely on that tape for long.
We use stainless wire clips like Heyco SunRunner or RevRunner attached to the 
module frame.
https://www.heyco.com/Solar_Power_Components/?sub=wire-management

The QCells AC modules have the microinverters attached so they hang down past 
the module frame so that the support rails cannot be within 12" of the module 
edge. Also it makes attaching the Enphase trunk cable difficult.
I find this inconvenient and no longer use the AC modules.

DonBarch
d...@energysolarnow.com

On Thu, Jun 2, 2022 at 9:37 AM Dave Tedeyan via RE-wrenches <
re-wrenches@lists.re-wrenches.org> wrote:

> Hi All,
>
> I just got some of the Qcell 360w AC modules that have the Enphase
> microinverter factory applied to the back. The module is the half cut cell
> type with the DC leads coming from either side of the middle of the module.
> The modules come with the wires taped to the back of the module. If you
> remove that tape, there appears to be almost no way to properly manage
> those wires. Is that tape meant to just keep the wire on the back of the
> module forever? Would that even last more than a year? I am curious what
> other people have done for these if they have used them or something
> similar. Maybe if you get the rail in the right spot, the wires will just
> sit on the rail...
>
> I realize that we have had a thread on wire management with half cut cell
> modules before, but this is a little different, as I am specifically asking
> about that tape and if anyone knows if it holds up over time.
>
> Cheers,
> Dave
>
> --
> [image: Logo] 
> Dave Tedeyan, P.E.
> Owner | Sungineer Solar
> p: he | him | his
> a: 1653 Slaterville Rd. | Ithaca, NY 14850
> w: www.sungineersolar.com 
> 
> c: (607) 288-2898
> 
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[RE-wrenches] SMA Rapid Shutdown and Secure Power Supply

[don energysolarnow.com via RE-wrenches]

Date: Wed, 27 Apr 2022 12:08:24 -0400
From: Dave Tedeyan 
To: RE-wrenches 
Subject: [RE-wrenches] SMA Rapid Shutdown and Secure Power Supply
Message-ID:

Content-Type: text/plain; charset="utf-8"

Hi All,

The last SMA-41 inverter I commissioned, had the option for SunSpec rapid
shutdown with Secure Power Supply. I just talked to a level one tech who
was not particularly familiar, but told me that with a sunspec rapid
shutdown device like the JMS-F, you can still use the Secure Power Supply
as if there was no rapid shutdown. I had stopped installing the SPS on
rooftop systems, because if losing grid power initiates rapid shutdown,
then you clearly do not have the power to run a SPS. But it sounds like
maybe the inverter has the smarts to wake the solar back up once you flip
the switch to activate the SPS. Can anyone here verify this? Have you done
this, and does it work as expected with no extra hardware needed?

Cheers,
Dave

--
[image: Logo] 
Dave Tedeyan, P.E.
Owner | Sungineer Solar
p: he | him | his
a: 1653 Slaterville Rd. | Ithaca, NY 14850
w: www.sungineersolar.com 

c: (607) 288-2898

Hi Dave
I just installed a pair of SB7.7-US41 inverters with the JMS-F Sunspec devices.
The onboard software setup specifies that the Secure Power outlet will not work 
with the JMS-F devices.
These are de-activated when the AC power is off, so even if you connected the 
Secure Power outlet there is no signal to turn on the JMS-F switches.

Don Barch
Energy Solar
707-483-4751
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