Re: [RE-wrenches] Radian Question

[Jay via RE-wrenches]

Drake I forgot to ask, but I’m thinking this is a new problem on an older system that was working normally?JayOn Oct 30, 2023, at 11:15 AM, david quattro via RE-wrenches  wrote:I’m not familiar with Outback defaults but most inverters I’ve dealt with have a grid tolerance of 10% +/-  so 216 to 264VAC.On Mon, Oct 30, 2023 at 6:57 AM Drake Chamberlin via RE-wrenches  wrote:
Hi Jay,
The inverter won't even connect to the grid. It stays in the state where it is sampling the grid, AC in light blinking. 
Is the default high voltage for the nominal 240 V 280? (IE 140 V X 2). 

Thanks for your help.

Drake 

Drake Chamberlin
Athens Electric LLC
Ohio Electrical Contractor’s License 44810
NABCEP Certified PV Installation Professional
---
 


On 2023-10-29 15:45, Jay via RE-wrenches wrote:



 
Hi drake
 
The early mate 3 has a glitch which I think they changed in the 3s. 
 
You e got to set the rebulk volts above what you want it to charge at. 
 
IE if the battery volts don't get below the rebulk volts it won't charge. 
 
So if your shallow cycling the batteries it's common it won't get below the rebulk volts. If you're deep cycling it usually will with default settings 
 
The default high voltage window for ac input is default at 140v. 
 
Hope this helps
 
Jay
 
 
 
 

On Oct 29, 2023, at 11:14 AM, Drake Chamberlin via RE-wrenches  wrote:



My Radian GS 8048  intermittently will connect to the grid to charge batteries. The grid voltage seems to run high around here. Yesterday, it wouldn't connect. The grid voltage was at 251 V. Later it did connect. At that point the grid was at 246 V.
 
I am suspecting that the Radian has a voltage acceptance limit of 250 V. Is that true? Is it possible to open up the window?
 
If that isn't it, what could be the problem?
 
Thank you,
 
Drake 
 

Drake Chamberlin
Athens Electric LLC
Ohio Electrical Contractor's License 44810
NABCEP Certified PV Installation Professional

 

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Re: [RE-wrenches] AC Coupling

[Kienan Maxfield via RE-wrenches]

That is my point was that the only consideration that deals with overcharge 
that I could possibly think of is with systems that have a poor implementation 
of the frequency shift (like the older Schneiders).


I think that AC coupling gets a black eye from the old days and from brands 
that have bad implementations. They also get a black eye from installers who 
don't program the systems correctly.


So to set matters straight, IF you use good equipment, and IF you program it 
right, then you do get a nice taper charge with AC coupling. I know it hasn't 
always been that way, but we are talking about today, not 5 or 10 years ago. I 
have tested it and seen it myself. You get good smooth 3 stage charging, 
completely controlled by the battery-based inverter, and it's based on the 
inverter's voltage sensors. I'm not going to try to make any overarching 
statements beyond the brands I have hands-on experience with (Outback and 
Victron) but with these systems, it is no different than charging with a charge 
controller. The tapering effect is there whether it's open loop (traditional 
system with no comms) or whether it's closed loop, or SOC based.


Most people also misunderstand closed loop communications. With most brands, 
you can't see what's going on, but because Victron is open source, you can look 
in and see exactly what is going on. What I'm about to say may have some 
exceptions (Like the Sunny Island).
Generally speaking, the charge controllers and inverters still operate very 
similar to how they do with Lead Acid batteries, but instead of you manually 
putting in the charge voltage and current limitations, the BMS sends the Max 
Voltage and Max Current parameters, so the inverters and charge controllers 
just override their parameters based on the last instruction from the BMS. The 
BMS sends 3 parameters, Max Charge Voltage, Max Charge Current, and Max 
Discharge Current. When you start charging a discharged battery, the BMS will 
send parameters telling it to charge to a specified voltage not to exceed a 
specified maximum current (basically a bulk/absorb charge). Once the BMS 
decides that the battery is sufficiently balanced and at 100%, it ends this 
"absorb" charge by sending a new set of parameters to the system. The new set 
of parameters will have either a reduced voltage, a reduced current, or both. 
If heat is generated in the battery at any time, or if any one cell has too 
high of a voltage at any time, then the BMS will send a new set of parameters 
to reduce the charge voltage/current accordingly. The only element that SOC 
plays in the whole affair is helping the BMS to know when to send what charging 
parameters. Of course, if the batteries get too cold, the BMS will likely send 
a new set of parameters with charge current set to 0A. In any case, whether you 
like Closed Loop comms or whether you hate them, that has no bearing on AC 
coupled vs DC coupled.

So whether you have closed loop communications or whether you have open loop 
communications won't really determine too much how good or bad the AC coupling 
is for Lithium batteries... If you have it set up right with frequency-Watt, 
then you'll have a nice taper charge either way. Without closed loop, you'll 
have a nice taper charge at your absorb voltage, and you'll have tapered float 
voltage. With Closed-loop, you'll have a nice tapered charge dictated by the 
voltages and currents desired by the BMS.


I want to make one thing abundantly clear before I sign off... Most AC coupled 
systems I've seen are not programmed correctly... the installer never 
programmed the Grid-direct inverter to function correctly for frequency-watt. 
In this case, then everything I have said goes out the window, and AC coupled 
systems that are set up in this way are really bad for the batteries. If this 
mistake is made, then it is really hard on the batteries just like Steve 
Higgins was talking about, and it totally makes sense that this would void the 
warranty.

Have a great day! 73,
Kienan Maxfield


Green-Go Solar Wholesale Distribution

maxfieldso...@hotmail.com

(801) 631-5584(Cell)

www.distribution.solar



From: RE-wrenches  on behalf of 
Jason Szumlanski via RE-wrenches 
Sent: Monday, October 30, 2023 8:32 AM
To: RE-wrenches 
Cc: Jason Szumlanski 
Subject: Re: [RE-wrenches] AC Coupling

I read through this thread, and I don't think one important aspect was covered 
with respect to "overcharging" batteries. There may be risk with lead acid 
batteries connected to a hybrid inverter that is AC coupled. But LiPO batteries 
have a BMS that is there, in part, to protect the battery from an overcharge 
scenario. The BMS is going to disconnect the battery before catastrophe 
strikes. In my opinion, AC Coupling is better suited to modern equipment that 
talks to each other in a closed loop. Crude algorithms for throttling PV don't 
seem particularly 

Re: [RE-wrenches] Radian Question

[david quattro via RE-wrenches]

I’m not familiar with Outback defaults but most inverters I’ve dealt with
have a grid tolerance of 10% +/-  so 216 to 264VAC.



On Mon, Oct 30, 2023 at 6:57 AM Drake Chamberlin via RE-wrenches <
re-wrenches@lists.re-wrenches.org> wrote:

> Hi Jay,
>
> The inverter won't even connect to the grid. It stays in the state where
> it is sampling the grid, AC in light blinking.
>
> Is the default high voltage for the nominal 240 V 280? (IE 140 V X 2).
>
>
> Thanks for your help.
>
>
> Drake
>
>
> *Drake Chamberlin*
>
> *Athens Electric LLC*
>
> *Ohio Electrical Contractor’s License 44810*
>
> *NABCEP Certified PV Installation Professional*
> ---
>
>
>
> On 2023-10-29 15:45, Jay via RE-wrenches wrote:
>
>
> Hi drake
>
> The early mate 3 has a glitch which I think they changed in the 3s.
>
> You e got to set the rebulk volts above what you want it to charge at.
>
> IE if the battery volts don't get below the rebulk volts it won't charge.
>
> So if your shallow cycling the batteries it's common it won't get below
> the rebulk volts. If you're deep cycling it usually will with default
> settings
>
> The default high voltage window for ac input is default at 140v.
>
> Hope this helps
>
> Jay
>
>
>
>
>
> On Oct 29, 2023, at 11:14 AM, Drake Chamberlin via RE-wrenches <
> re-wrenches@lists.re-wrenches.org> wrote:
>
> My Radian GS 8048 intermittently will connect to the grid to charge
> batteries. The grid voltage seems to run high around here. Yesterday, it
> wouldn't connect. The grid voltage was at 251 V. Later it did connect. At
> that point the grid was at 246 V.
>
> I am suspecting that the Radian has a voltage acceptance limit of 250 V.
> Is that true? Is it possible to open up the window?
>
> If that isn't it, what could be the problem?
>
> Thank you,
>
> Drake
>
>
> *Drake Chamberlin*
>
> *Athens Electric LLC*
>
> *Ohio Electrical Contractor's License 44810*
>
> *NABCEP Certified PV Installation Professional*
>
>
>
> --
>
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Re: [RE-wrenches] AC Coupling

[Jason Szumlanski via RE-wrenches]

There isn't a failsafe system. For example, if you have a battery
temperature sensor dislodged from a lead acid battery, you can have
overcharged (or undercharged) batteries. And there is no perfect algorithm
for charging based on voltage, either. And as batteries age, you have to
adjust setpoints for optimum charging (which undoubtedly doesn't happen in
many cases). There have been cases where I wish lead acid batteries did
have a shutoff to avoid catastrophe (I've "boiled" the electrolyte out of
some unattended batteries before). Fortunately, they were my own and not a
customer's. I would agree that SOC is a pretty poor metric unless a BMS can
accurately relay that to an external charging system.

In my opinion, the safest and best way to AC Couple is with a single
manufacturer handling all aspects. The number of Enphase battery systems
out there is very quickly growing, and aside from wireless communication
issues in the past generation, I have not experienced or heard of any
significant issues. Battery charging safety is not impaired by
communication issues since the batteries simply will not charge or
discharge in this error state. And since the system is modular, a single
battery failure does not take down the entire system, which is admittedly a
problem with some AC Coupled solutions (the potential black start issue).
But Enphase has that resolved for systems using the IQ8 microinverters,
which have black start capability (they call it Sunlight Jump Start). Of
course, Enphase doesn't do off-grid, so it's a moot point for non-grid tied
systems.

There are a lot of unknowns in new technology, so I am tiptoeing into AC
Coupling with other solutions that have closed-loop communication.
Admittedly, I have my concerns, but I'm also pretty confident that the
manufacturers of the equipment are working very closely together based on
what I have seen. However, there is risk in that as well. I have concerns,
for example, with Sol-Ark starting to sell their own battery. I'm not
saying they will stop cooperating with other brands, but they do have an
incentive to push their own brand of battery, I would assume.

Jason Szumlanski
Principal Solar Designer | Florida Solar Design Group
NABCEP Certified Solar Professional (PVIP)
Florida State Certified Solar Contractor CVC56956


On Mon, Oct 30, 2023 at 10:54 AM William Miller via RE-wrenches <
re-wrenches@lists.re-wrenches.org> wrote:

> Jason:
>
>
>
> Thanks for contributing to this thread.  I did not realize it would create
> so much interest.  My main point is to establish a definition for
> AC-coupling, and I believe we do have consensus on that.  The next question
> to ask is AC-coupling a good thing?
>
>
>
> You make the point that BMS systems protect lithium batteries from
> damage.  They do so by shutting down, not correcting the problem.  But what
> good is a system that shuts down?  When that happens someone has to roll a
> truck to reset the system.  We should not design outages into our systems.
>
>
>
> I spoke at length this weekend with a very knowledgeable member of this
> forum (thank you, sir) about closed loop.  Their experience is that there
> were packet losses in the communications and when that occurred the system
> shut down.  I am going to set up my first closed loop today and I hope I do
> not have the same experience.
>
>
>
> Traditional charge controllers may seem “crude” but they operate on real,
> measured values of voltage and current, values that are at the core of
> battery care.  Modern charging systems seem to rely at least partially on
> sate of charge.  State of charge is a calculated value that is notorious
> for being inaccurate and drifting more so over time.  Every SOC scheme I
> know needs to be recalibrated frequently.  The recalibration requires
> hitting certain charge parameters and if you can’t hit those you don’t
> recalibrate.
>
>
>
> I assumed that a BMS system provided within a lithium battery assembly by
> the manufacturer would be accurate.  I spoke with a tech support person
> from a prominent LFP manufacturer at length recently and was told their BMS
> is not foolproof on calculating SOC.  I am not confident that any of them
> are.
>
>
>
> I am new to lithium battery systems.  It may be my inexperience talking,
> but it seems they incorporate a lot of complexity that may make them
> unreliable unless charged and discharged very carefully.  I do not believe
> AC-coupled charging is a good way to charge lithium batteries, or any
> battery.
>
>
>
> William Miller
>
>
>
> Miller Solar
>
> 17395 Oak Road, Atascadero, CA 93422
>
> 805-438-5600
>
> www.millersolar.com
>
> CA Lic. 773985
>
>
>
>
>
> *From:* RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] *On
> Behalf Of *Jason Szumlanski via RE-wrenches
> *Sent:* Monday, October 30, 2023 7:33 AM
> *To:* RE-wrenches
> *Cc:* Jason Szumlanski
> *Subject:* Re: [RE-wrenches] AC Coupling
>
>
>
> I read through this thread, and I don't think one important aspect 

Re: [RE-wrenches] AC Coupling

[Steve Higgins via RE-wrenches]

Good Morning Wrenches,

AC-coupled systems are generally not pleasant to batteries of any type.  I
would not AC Couple any Valve Regulated Battery system as you are, in
essence, "overcharging" them at times, and this can and has led to battery
failures (usually overcharging and swelling) that all battery
manufacturers will not cover under warranty.Flooded batteries can take
this abuse a bit more, but this can still result in drying the batteries
out and corrosion or degradation of the negative plate due to heat.

Lithium batteries do not like this, but the BMS will shut off the charge to
the battery bank. It doesn't power off the battery but stops the excessive
charge to the battery, but these unloaded voltages on the input of the
battery can stress the BMS depending on how much voltage is seen.

Ideally, if you are AC coupling, it's better to use a system that tapers
charging and voltage depending on SOC, to do this you'll need closed loop
communication, with the inverter/charger so the battery can shut down or
slow charging depending on SOC.



 
 
 
 
 
 
 
 
 
Steve Higgins ⋅ Technical Services Manager
t +1.902.597.4020  m +1.206.790.5840
f +1.902.597.8447  e st...@surrette.com










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On Mon, Oct 30, 2023 at 8:53 AM William Miller via RE-wrenches <
re-wrenches@lists.re-wrenches.org> wrote:

> Jason:
>
>
>
> Thanks for contributing to this thread.  I did not realize it would create
> so much interest.  My main point is to establish a definition for
> AC-coupling, and I believe we do have consensus on that.  The next question
> to ask is AC-coupling a good thing?
>
>
>
> You make the point that BMS systems protect lithium batteries from
> damage.  They do so by shutting down, not correcting the problem.  But what
> good is a system that shuts down?  When that happens someone has to roll a
> truck to reset the system.  We should not design outages into our systems.
>
>
>
> I spoke at length this weekend with a very knowledgeable member of this
> forum (thank you, sir) about closed loop.  Their experience is that there
> were packet losses in the communications and when that occurred the system
> shut down.  I am going to set up my first closed loop today and I hope I do
> not have the same experience.
>
>
>
> Traditional charge controllers may seem “crude” but they operate on real,
> measured values of voltage and current, values that are at the core of
> battery care.  Modern charging systems seem to rely at least partially on
> sate of charge.  State of charge is a calculated value that is notorious
> for being inaccurate and drifting more so over time.  Every SOC scheme I
> know needs to be recalibrated frequently.  The recalibration requires
> hitting certain charge parameters and if you can’t hit those you don’t
> recalibrate.
>
>
>
> I assumed that a BMS system provided within a lithium battery assembly by
> the manufacturer would be accurate.  I spoke with a tech support person
> from a prominent LFP manufacturer at length recently and was told their BMS
> is not foolproof on calculating SOC.  I am not confident that any of them
> are.
>
>
>
> I am new to lithium battery systems.  It may be my inexperience talking,
> but it seems they incorporate a lot of complexity that may make them
> unreliable unless charged and discharged very carefully.  I do not believe
> AC-coupled charging is a good way to charge lithium batteries, or any
> battery.
>
>
>
> William Miller
>
>
>
> Miller Solar
>
> 17395 Oak Road, Atascadero, CA 93422
>
> 805-438-5600
>
> 

Re: [RE-wrenches] AC Coupling

[William Miller via RE-wrenches]

Jason:



Thanks for contributing to this thread.  I did not realize it would create
so much interest.  My main point is to establish a definition for
AC-coupling, and I believe we do have consensus on that.  The next question
to ask is AC-coupling a good thing?



You make the point that BMS systems protect lithium batteries from damage.
They do so by shutting down, not correcting the problem.  But what good is
a system that shuts down?  When that happens someone has to roll a truck to
reset the system.  We should not design outages into our systems.



I spoke at length this weekend with a very knowledgeable member of this
forum (thank you, sir) about closed loop.  Their experience is that there
were packet losses in the communications and when that occurred the system
shut down.  I am going to set up my first closed loop today and I hope I do
not have the same experience.



Traditional charge controllers may seem “crude” but they operate on real,
measured values of voltage and current, values that are at the core of
battery care.  Modern charging systems seem to rely at least partially on
sate of charge.  State of charge is a calculated value that is notorious
for being inaccurate and drifting more so over time.  Every SOC scheme I
know needs to be recalibrated frequently.  The recalibration requires
hitting certain charge parameters and if you can’t hit those you don’t
recalibrate.



I assumed that a BMS system provided within a lithium battery assembly by
the manufacturer would be accurate.  I spoke with a tech support person
from a prominent LFP manufacturer at length recently and was told their BMS
is not foolproof on calculating SOC.  I am not confident that any of them
are.



I am new to lithium battery systems.  It may be my inexperience talking,
but it seems they incorporate a lot of complexity that may make them
unreliable unless charged and discharged very carefully.  I do not believe
AC-coupled charging is a good way to charge lithium batteries, or any
battery.



William Miller



Miller Solar

17395 Oak Road, Atascadero, CA 93422

805-438-5600

www.millersolar.com

CA Lic. 773985





*From:* RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] *On
Behalf Of *Jason Szumlanski via RE-wrenches
*Sent:* Monday, October 30, 2023 7:33 AM
*To:* RE-wrenches
*Cc:* Jason Szumlanski
*Subject:* Re: [RE-wrenches] AC Coupling



I read through this thread, and I don't think one important aspect was
covered with respect to "overcharging" batteries. There may be risk with
lead acid batteries connected to a hybrid inverter that is AC coupled. But
LiPO batteries have a BMS that is there, in part, to protect the battery
from an overcharge scenario. The BMS is going to disconnect the battery
before catastrophe strikes. In my opinion, AC Coupling is better suited to
modern equipment that talks to each other in a closed loop. Crude
algorithms for throttling PV don't seem particularly confidence-inspiring.
This is one argument for sticking with a single manufacturer system
architecture (i.e. Enphase). While there are obvious downsides and
limitations to that, the system should work safely and flawlessly in an AC
Coupled scenario.



With respect to mixed systems with DC and AC Coupling, while I see the
advantages, it really complicates the design and installation. It also
greatly confuses the monitoring aspect for PV production. I think it
depends on the scenario, but going one way or the other makes the most
sense to me in most situations. With that said, there are exceptions. For
example, I have a Sol-Ark 15K client right now where all of the MPPT inputs
are taken, and reconfiguring the DC coupled strings is not easily achieved.
So, to add more PV, the obvious choice is to AC couple. But this system has
a generator, so the AC Coupled PV needs to be on the AC load output,
meaning it will not be monitored by the Sol-Ark. That's not ideal, but it's
nice to have that flexibility.


Jason Szumlanski

Principal Solar Designer | Florida Solar Design Group
NABCEP Certified Solar Professional (PVIP)
Florida State Certified Solar Contractor CVC56956





On Sun, Oct 29, 2023 at 4:19 PM Kienan Maxfield via RE-wrenches <
re-wrenches@lists.re-wrenches.org> wrote:

William,



My whole email is in regards to the point you made when you said

"This is not how battery inverters were originally designed to operate.
These systems require careful consideration to avoid battery overcharging."



I both agree and disagree with these statements... depending on what you
mean. I don't think it's super helpful to say that careful considerations
are required without mentioning what those considerations are, and I'll get
to those below.











When you say that the battery inverters "weren't *originally* designed for
this" I'd agree to an extent.. The "original" battery based inverters 25
years ago were certainly not designed for AC coupling. They weren't
"originally" designed for it. But that was then and this is now.

Re: [RE-wrenches] Metal Truss Roofs

[Daryl DeJoy via RE-wrenches]

We have used Marutek molybdenum self tapping screws successfully for the
past fifteen years in the Bahamas on metal truss roofs. On the East Coat,
Manasquan Fasteners is our go-to fastener company.

Daryl DeJoy

On Mon, Oct 30, 2023, 10:46 AM Jason Szumlanski via RE-wrenches <
re-wrenches@lists.re-wrenches.org> wrote:

> I agree that you can get impressive pull-out resistance from fasteners in
> plywood decking only. Two brands that publish pull-out values are
> OMG/Drill-Tec and Blazer. The #15 OMG screws are what we lean toward.
>
> John Mansville also has a "High Load Fastener," but I think it's just a
> rebranded OMG. It comes in #14, #15, and even #21. They have published
> pull-out values that are really high. If you use a base plate with 4
> fasteners with a 3x safety factor, you still get enormous pull-out values.
>
> Jason Szumlanski
> Principal Solar Designer | Florida Solar Design Group
> NABCEP Certified Solar Professional (PVIP)
> Florida State Certified Solar Contractor CVC56956
>
>
> On Thu, Oct 26, 2023 at 2:06 PM August Goers via RE-wrenches <
> re-wrenches@lists.re-wrenches.org> wrote:
>
>> Hi James,
>>
>> I haven't had an application exactly as you describe with a tile roof /
>> plywood deck over metal trusses. However, we have installed systems with
>> metal roof support structures many times. Metal self-drilling screws have
>> impressive pullouts, so you might be able to use them with any sort of
>> mount that you want that works with the tiles you have on site. We have
>> used ELCO screws in the past, and they are now part of the DeWalt brands,
>> but here is an example:
>>
>> https://anchors.dewalt.com/anchors/products/screw-fasteners/
>>
>> and a Drill-Flex example:
>>
>>
>> https://anchors.dewalt.com/anchors/_documents/uploads/DWANF_DrilFlex-TP-EN-rA_DDS1.pdf?1698346503
>>
>> Some of these fasteners are completely self drilling while others require
>> a pilot hole.
>>
>> Best,
>>
>> August
>> Luminalt
>>
>>
>> On Thu, Oct 26, 2023 at 10:17 AM James Rudolph via RE-wrenches <
>> re-wrenches@lists.re-wrenches.org> wrote:
>>
>>> Mahalo for your response Sam. That makes me feel a little better.
>>>
>>>
>>> James B. Rudolph
>>>
>>>
>>> Independent Energy
>>>
>>> C-39784 ES #10816
>>>
>>> NABCEP Certified PV Installer since 2009  #091209-155
>>>
>>> C. 808.313.9701
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> On Thu, Oct 26, 2023 at 6:08 AM Sam Haraldson 
>>> wrote:
>>>
 James,

 I can think of one install I performed in 2017 that was a metal roof
 over metal purlins and we opted to through-bolt the entire array using one
 installer on a ladder inside and another on the roof.  We employed butyl
 mastic and large fender washers to attach a strut frame to the roof, and
 then we installed traditional L-feet and rails atop the strut.  I have zero
 experience working with tile so I don't know what your best methodology is
 there but I can attest that the through-bolting has held up well at that
 site the past five years.

 Sincerely,
 Sam Haraldson

 [image: OnSite Energy]
 

 SAM HARALDSON
 Field Operations Director
 (406) 551-6135
 1515 N. Rouse Ave Bozeman, MT 59715
 Locally owned and operated since 2012
 [image: B Corporation]
 

>>> ___
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Re: [RE-wrenches] Metal Truss Roofs

[Jason Szumlanski via RE-wrenches]

I agree that you can get impressive pull-out resistance from fasteners in
plywood decking only. Two brands that publish pull-out values are
OMG/Drill-Tec and Blazer. The #15 OMG screws are what we lean toward.

John Mansville also has a "High Load Fastener," but I think it's just a
rebranded OMG. It comes in #14, #15, and even #21. They have published
pull-out values that are really high. If you use a base plate with 4
fasteners with a 3x safety factor, you still get enormous pull-out values.

Jason Szumlanski
Principal Solar Designer | Florida Solar Design Group
NABCEP Certified Solar Professional (PVIP)
Florida State Certified Solar Contractor CVC56956


On Thu, Oct 26, 2023 at 2:06 PM August Goers via RE-wrenches <
re-wrenches@lists.re-wrenches.org> wrote:

> Hi James,
>
> I haven't had an application exactly as you describe with a tile roof /
> plywood deck over metal trusses. However, we have installed systems with
> metal roof support structures many times. Metal self-drilling screws have
> impressive pullouts, so you might be able to use them with any sort of
> mount that you want that works with the tiles you have on site. We have
> used ELCO screws in the past, and they are now part of the DeWalt brands,
> but here is an example:
>
> https://anchors.dewalt.com/anchors/products/screw-fasteners/
>
> and a Drill-Flex example:
>
>
> https://anchors.dewalt.com/anchors/_documents/uploads/DWANF_DrilFlex-TP-EN-rA_DDS1.pdf?1698346503
>
> Some of these fasteners are completely self drilling while others require
> a pilot hole.
>
> Best,
>
> August
> Luminalt
>
>
> On Thu, Oct 26, 2023 at 10:17 AM James Rudolph via RE-wrenches <
> re-wrenches@lists.re-wrenches.org> wrote:
>
>> Mahalo for your response Sam. That makes me feel a little better.
>>
>>
>> James B. Rudolph
>>
>>
>> Independent Energy
>>
>> C-39784 ES #10816
>>
>> NABCEP Certified PV Installer since 2009  #091209-155
>>
>> C. 808.313.9701
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> On Thu, Oct 26, 2023 at 6:08 AM Sam Haraldson 
>> wrote:
>>
>>> James,
>>>
>>> I can think of one install I performed in 2017 that was a metal roof
>>> over metal purlins and we opted to through-bolt the entire array using one
>>> installer on a ladder inside and another on the roof.  We employed butyl
>>> mastic and large fender washers to attach a strut frame to the roof, and
>>> then we installed traditional L-feet and rails atop the strut.  I have zero
>>> experience working with tile so I don't know what your best methodology is
>>> there but I can attest that the through-bolting has held up well at that
>>> site the past five years.
>>>
>>> Sincerely,
>>> Sam Haraldson
>>>
>>> [image: OnSite Energy]
>>> 
>>>
>>> SAM HARALDSON
>>> Field Operations Director
>>> (406) 551-6135
>>> 1515 N. Rouse Ave Bozeman, MT 59715
>>> Locally owned and operated since 2012
>>> [image: B Corporation]
>>> 
>>>
>> ___
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Re: [RE-wrenches] Discoloring Solar World panels

[Jason Szumlanski via RE-wrenches]

I have the same question as Jerry. It's not brand-specific, either. We have
had panels from various manufacturers over the years where we installed
them, and clients noticed a difference in color/look/reflectivity from day
one essentially. Sometimes, it's just the angle you are looking at them. We
have replaced modules from time to time to "fix" this problem, which isn't
a performance issue but an aesthetic one.

Jason Szumlanski
Principal Solar Designer | Florida Solar Design Group
NABCEP Certified Solar Professional (PVIP)
Florida State Certified Solar Contractor CVC56956


On Sun, Oct 29, 2023 at 12:23 AM Jerry Shafer via RE-wrenches <
re-wrenches@lists.re-wrenches.org> wrote:

> Wrenches
> Are you 100% sure there was not a difference when new. I have seen
> different colors with sharps way back when out of the box, solarworld with
> some b on b had different shades so unles it's getting hotter then it may
> be best to monitor and watch over time, it's not like you can call
> solarworld and get help.
> Funtimes
>
> On Fri, Oct 27, 2023, 5:11 PM Solar Energy Solutions via RE-wrenches <
> re-wrenches@lists.re-wrenches.org> wrote:
>
>> Dear Amazing Wrenchs,
>>
>> A client of ours just sent us a photo of a system we installed a while
>> ago using SolarWorld 300 panels. He, and now I, am concerned about the
>> discoloration.  Thoughts???
>>
>> [image: image0.jpeg]
>>
>> *Andrew Koyaanisqatsi*
>> *President*
>> *Solar Energy Solutions, Inc.*
>> *The BRIGHT CHOICE*
>>
>> *Since 1987,** helping you and your Portland neighbors move** towards an
>> environmentally sustainable future.*
>>
>> *503-238-4502www.SolarEnergyOregon.com
>> *
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Re: [RE-wrenches] AC Coupling

[Jason Szumlanski via RE-wrenches]

I read through this thread, and I don't think one important aspect was
covered with respect to "overcharging" batteries. There may be risk with
lead acid batteries connected to a hybrid inverter that is AC coupled. But
LiPO batteries have a BMS that is there, in part, to protect the battery
from an overcharge scenario. The BMS is going to disconnect the battery
before catastrophe strikes. In my opinion, AC Coupling is better suited to
modern equipment that talks to each other in a closed loop. Crude
algorithms for throttling PV don't seem particularly confidence-inspiring.
This is one argument for sticking with a single manufacturer system
architecture (i.e. Enphase). While there are obvious downsides and
limitations to that, the system should work safely and flawlessly in an AC
Coupled scenario.

With respect to mixed systems with DC and AC Coupling, while I see the
advantages, it really complicates the design and installation. It also
greatly confuses the monitoring aspect for PV production. I think it
depends on the scenario, but going one way or the other makes the most
sense to me in most situations. With that said, there are exceptions. For
example, I have a Sol-Ark 15K client right now where all of the MPPT inputs
are taken, and reconfiguring the DC coupled strings is not easily achieved.
So, to add more PV, the obvious choice is to AC couple. But this system has
a generator, so the AC Coupled PV needs to be on the AC load output,
meaning it will not be monitored by the Sol-Ark. That's not ideal, but it's
nice to have that flexibility.

Jason Szumlanski
Principal Solar Designer | Florida Solar Design Group
NABCEP Certified Solar Professional (PVIP)
Florida State Certified Solar Contractor CVC56956


On Sun, Oct 29, 2023 at 4:19 PM Kienan Maxfield via RE-wrenches <
re-wrenches@lists.re-wrenches.org> wrote:

> William,
>
> My whole email is in regards to the point you made when you said
>
> "This is not how battery inverters were originally designed to operate.
> These systems require careful consideration to avoid battery overcharging."
>
>
> I both agree and disagree with these statements... depending on what you
> mean. I don't think it's super helpful to say that careful considerations
> are required without mentioning what those considerations are, and I'll get
> to those below.
>
>
>
>
>
> When you say that the battery inverters "weren't *originally* designed
> for this" I'd agree to an extent.. The "original" battery based
> inverters 25 years ago were certainly not designed for AC coupling. They
> weren't "originally" designed for it. But that was then and this is now.
>
>
>
>
>
> Now William is correct that the Gen input becomes an AC output, and you
> can't wire the gen into that "input" if you are using it as a PV input...
> that being said, Jay didn't think otherwise, he was just critiquing the
> wiring diagram in the original post to say that it wires up differently, so
> I'd say that you are both right on this one. That said, I don't think
> anyone says you have to wire it into the gen port, I think that even with
> the hybrid inverters, the way in William's original post is still a fully
> acceptable way to do it.
>
>
>
> I am not a huge fan of AC coupling, however, I have done it a fair amount
> and I have a fair amount of experience with it off-grid with Lithium and
> with Lead Acid. Most of my experience is with Outback and Victron, but I
> have some experience with Schneider as well. These systems have been
> working really well for a good while, but that being said, Schneider had
> some real problems at first (major headache).
>
>
> Now when it comes to hybrid inverters, I'm still not a huge fan... but I'm
> starting to try them out. I have not tested AC coupling with any of them
> yet. I was at a conference less than a year ago and one of the major brands
> was saying that there is no hybrid inverter that supports both AC coupled
> PV and a generator at the same time for a grid tied system. They said "you
> can't have it all." There may be an exception to that, I've never looked
> into it, but with the Victron and Outback (and probably Scheider... IDK)
> it's easy to have it all. I've done it and it works well in every mode. The
> frequency changes super fast and assuming you have a properly programmed
> rule 21 compliant Grid tied inverter, it responds very quickly, and in the
> systems I've monitored, the frequency never had to go above 62 Hz, which is
> good enough for most sensitive loads. The inverters are totally designed
> for this these days, but if you have highly sensitive loads, then it may
> not work well.
>
>
>
> *Considerations...*
> First of all, I will be assuming that you are using quality rule 21
> grid-direct inverters and a good battery inverter that works as well as the
> Outback Radian or the Victron. The early Schneiders were too slow in
> changing their frequency, and special considerations had to be accounted
> for because of that, but I heard that was 

Re: [RE-wrenches] Radian Question

[Drake Chamberlin via RE-wrenches]

Hi Jay, 


The inverter won't even connect to the grid. It stays in the state where
it is sampling the grid, AC in light blinking. 

Is the default high voltage for the nominal 240 V 280? (IE 140 V X 2). 

Thanks for your help. 

Drake 

_Drake Chamberlin_ 

_Athens Electric LLC_ 

_Ohio Electrical Contractor's License 44810_ 


_NABCEP Certified PV Installation Professional_

---

On 2023-10-29 15:45, Jay via RE-wrenches wrote:

Hi drake 

The early mate 3 has a glitch which I think they changed in the 3s.  

You e got to set the rebulk volts above what you want it to charge at.  

IE if the battery volts don't get below the rebulk volts it won't charge.  

So if your shallow cycling the batteries it's common it won't get below the rebulk volts. If you're deep cycling it usually will with default settings  

The default high voltage window for ac input is default at 140v.  

Hope this helps 

Jay 


On Oct 29, 2023, at 11:14 AM, Drake Chamberlin via RE-wrenches 
 wrote:


My Radian GS 8048 intermittently will connect to the grid to charge batteries. The grid voltage seems to run high around here. Yesterday, it wouldn't connect. The grid voltage was at 251 V. Later it did connect. At that point the grid was at 246 V. 

I am suspecting that the Radian has a voltage acceptance limit of 250 V. Is that true? Is it possible to open up the window? 

If that isn't it, what could be the problem? 

Thank you, 

Drake 

_Drake Chamberlin_ 

_Athens Electric LLC_ 

_Ohio Electrical Contractor's License 44810_ 

_NABCEP Certified PV Installation Professional_ 


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