Re: [RE-wrenches] Troubleshooting Stumper - Homerun Interference in Conduit/Inverter Turning Off/On Rapidly

[Drake]

The maximizers sound like the most likely explanation to me.

That being said, one point in the diagnosis that I would still do is 
to Megger test the wiring while the wiring is in the conduit. If I 
understood correctly, the wiring was tested while out of the conduit. 
This can miss the problem since a wire can fault against the wall of 
a conduit and find nothing to fault to when out of the pipe.


At this point, I'd bet on the Tigo Maximizers being the most likely culprit.

At 12:38 PM 9/10/2016, you wrote:
Yes this is an interesting case, as are the debug suggestions given. 
The wire pairs working out of metal conduit point strongly at either 
ground faulting or inductive coupling. You seem to have eliminated 
the obvious wiring issues like polarity and grounding. Since you 
have a working system next door and you are already putting in the 
hard work of swapping inverters and wires, it is worth trying to 
swap the inverter from that working system with the non-working one. 
This would either indict or eliminate the inverter as the culprit.


It is worth noting that the TrinaSmart modules with Tigo Maximizers 
are quite capable of being the source of the problem. They attempt 
to do MPPT at the module level, and can conflict with the inverter's 
attempts at MPPT. We have had problems with other inverter brands to 
the extent that power production was impaired, although not as bad 
as your complete shutdown. It was necessary to use the inverter 
setup options to shut off MPPT. If Solectria allows this it is worth trying.
Also I have had problems with Tigo Maximizers on mismatched strings 
shutting down one string completely to "maximize" others. You may be 
seeing the effect of communication problems from the maximizer 
wireless controller. Try disabling them if possible by shutting down 
their controller with its secret software.
I'm guessing that plain dumb modules with a plain dumb inverter 
would not be suffering this shutdown problem. Something in your 
system is too smart for your own good.


Don Barch
Energy Solar

 Original Message 


-Original Message-
From: RE-wrenches 
[<mailto:re-wrenches-boun...@lists.re-wrenches.org>mailto:re-wrenches-boun...@lists.re-wrenches.org] 
On

Behalf Of Matt Partymiller
Sent: Wednesday, September 07, 2016 4:46 PM
To: 
<mailto:re-wrenches@lists.re-wrenches.org>re-wrenches@lists.re-wrenches.org

Subject: [RE-wrenches] Troubleshooting Stumper - Homerun Interference in
Conduit/Inverter Turning Off/On Rapidly

Wrenches,

One of our systems is having an issue I have not encountered before where
the inverter switches between nighttime mode and interconnection every few
seconds. I am hoping for some technical wisdom from the community.

We have an array of 20 TrinaSmart modules in two strings of 10. The array
is connected to a Solectria 3.8 kW inverter. The conduit run is simple, all
four homerun wires (#10 PVwire) in 1" EMT down to the proximity of the
Solectria inverter where the conduit switches to 1" LFMC before entering the
inverter. The run is about 20', straight down the side of the wall before
hitting the inverter. A 600V jacketed communications wire was also in the
conduit but has since been removed and run separately.

Our inverter is starting up, running for a few seconds, giving a low voltage
error, briefly showing nighttime mode, then going into startup mode again.
Solectria was gracious enough to send us a new inverter but we have the
exact same issue. They tell us their error codes (266, 274) indicate 0
volts. The transition between low voltage error and startup is almost
instant. Basically we have 20 seconds of start up, 5 seconds of run, 5
seconds of error then repeat. This is not a grid problem, the identical
system next door works fine.

In the process of troubleshooting, our technician pulled all four homerun
wires out of our conduit and meggered them. They all tested fine so he
connected to the inverter. The inverter worked fine. The technician
verified grounding of the array and conduit, pulled new homeruns back
through the conduit, and reconnected to the inverter. He had the same error
as before.

He connected each string separately to the inverter by removing the string
fuses. Either string will operate fine independently. With string one in
conduit and either homerun of string two in conduit (but not both) the
inverter operates fine. With string two in conduit but string one outside
of conduit, the inverter does not operate.

I was certain the error had something to do with homerun roof wiring so I
went out with the technician and removed and checked pretty much every
module. Everything appears fine, all connections solid, all homeruns have
been remade at least once at this point. Now I am stumped and lack the
technical knowledge to diagnose the problem. I would be extremely grateful
if an esteemed wrench can provide technical support/advice.

Thanks,

Matt




Matthew Partymiller
Sola

Re: [RE-wrenches] Troubleshooting Stumper - Homerun Interference in Conduit/Inverter Turning Off/On Rapidly

[don]

Yes this is an interesting case, as are the debug suggestions given. The wire pairs working out of metal conduit point strongly at either ground faulting or inductive coupling. You seem to have eliminated the obvious wiring issues like polarity and grounding. Since you have a working system next door and you are already putting in the 
hard work of swapping inverters and wires, it is worth trying to 
swap the inverter from that working system with the non-working one. 
This would either indict or eliminate the inverter as the culprit. It is worth noting that the TrinaSmart modules with Tigo Maximizers are quite capable of being the source of the problem. They attempt to do MPPT at the module level, and can conflict with the inverter's attempts at MPPT. We have had problems with other inverter brands to the extent that power production was impaired, although not as bad as your complete shutdown. It was necessary to use the inverter setup options to shut off MPPT. If Solectria allows this it is worth trying. Also I have had problems with Tigo Maximizers on mismatched strings shutting down one string completely to "maximize" others. You may be seeing the effect of communication problems from the maximizer wireless controller. Try disabling them if possible by shutting down their controller with its secret software.I'm guessing that plain dumb modules with a plain dumb inverter would not be suffering this shutdown problem. Something in your system is too smart for your own good.Don BarchEnergy Solar


 Original Message 

-Original Message-
From: RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] On
Behalf Of Matt Partymiller
Sent: Wednesday, September 07, 2016 4:46 PM
To: re-wrenches@lists.re-wrenches.org
Subject: [RE-wrenches] Troubleshooting Stumper - Homerun Interference in
Conduit/Inverter Turning Off/On Rapidly

Wrenches,

One of our systems is having an issue I have not encountered before where
the inverter switches between nighttime mode and interconnection every few
seconds.  I am hoping for some technical wisdom from the community.

We have an array of 20 TrinaSmart modules in two strings of 10.  The array
is connected to a Solectria 3.8 kW inverter.  The conduit run is simple, all
four homerun wires (#10 PVwire) in 1" EMT down to the proximity of the
Solectria inverter where the conduit switches to 1" LFMC before entering the
inverter.  The run is about 20', straight down the side of the wall before
hitting the inverter.  A 600V jacketed communications wire was also in the
conduit but has since been removed and run separately.

Our inverter is starting up, running for a few seconds, giving a low voltage
error, briefly showing nighttime mode, then going into startup mode again.
Solectria was gracious enough to send us a new inverter but we have the
exact same issue.  They tell us their error codes (266, 274) indicate 0
volts.  The transition between low voltage error and startup is almost
instant.  Basically we have 20 seconds of start up, 5 seconds of run, 5
seconds of error then repeat.  This is not a grid problem, the identical
system next door works fine.

In the process of troubleshooting, our technician pulled all four homerun
wires out of our conduit and meggered them.  They all tested fine so he
connected to the inverter.  The inverter worked fine.  The technician
verified grounding of the array and conduit, pulled new homeruns back
through the conduit, and reconnected to the inverter.  He had the same error
as before.

He connected each string separately to the inverter by removing the string
fuses.  Either string will operate fine independently.  With string one in
conduit and either homerun of string two in conduit (but not both) the
inverter operates fine.  With string two in conduit but string one outside
of conduit, the inverter does not operate.

I was certain the error had something to do with homerun roof wiring so I
went out with the technician and removed and checked pretty much every
module.  Everything appears fine, all connections solid, all homeruns have
been remade at least once at this point.  Now I am stumped and lack the
technical knowledge to diagnose the problem.  I would be extremely grateful
if an esteemed wrench can provide technical support/advice.

Thanks,

Matt




Matthew Partymiller
Solar Energy Solutions LLC
(877) 312-7456
m...@solar-energy-solutions.com


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Re: [RE-wrenches] Troubleshooting Stumper - Homerun Interference in Conduit/Inverter Turning Off/On Rapidly

[August Goers]

Certainly seems like a stumper so far! I'd still check voltage and
polarity with the strings through the conduit but not landed in the
inverter. We've seen all kinds of mistakes where the negatives were
mixed-up between strings, etc, causing strange behavior. Voltages can test
fine when landed in inverters (even with fuses pulled) but exhibit
different behavior when completely isolated. The fact that the system ran
at first would lead us to believe that the wiring was done properly,
however. It seems like the other suggestion of some sort of mild ground
fault is a good path to follow. I also would highly question how those
Tigo optimizers might be adding to the equation. You could also run the
inverter with everything wired up and your volt meter on the DC inputs to
see what is happening. The conduit factor here can only be causing ground
issues or possibly some kind of inductance hokey pokey, but that seems
unlikely.

August

-Original Message-
From: RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] On
Behalf Of Matt Partymiller
Sent: Wednesday, September 07, 2016 6:55 PM
To: RE-wrenches
Subject: Re: [RE-wrenches] Troubleshooting Stumper - Homerun Interference
in Conduit/Inverter Turning Off/On Rapidly

Thanks for all the questions and interest in my troubleshooting.

The polarities are definitely correct.  When testing wires at the inverter
with the DC disco off and fuses pulled, we see correct voltage on each
string.

We have tried using two clamp meters to measure current on each string
while operating the inverter with our homeruns in the conduit.  Using the
max function we never saw a meter get above about 1.5A (even less earlier
in the day).  String two seemed to be consistently lower but I really
wasn't sure if that was an inverter function or not as it ramps up towards
max power.  With the homeruns outside of conduit the inverter operates
fine and both strings show similar, but not identical, current.  Doing the
math it appeared each string was producing roughly half of inverter output
at that time.

To Jerry's question, the system did operate fine for about a week and 65
kWh.  The inverter then failed.  Our technician replaced that inverter
with a new Solectria 3.8 kW unit, restarted the unit, and noted the
problem.  With Solectria's help he arrived at the idea that we had a
faulty inverter, got a new one in, and noted the exact same error codes
and began trying to troubleshoot.  He left the third inverter installed
and also installed a new Tigo Cloud Connect and Gateway for the Trinasmart
system.

The modules are 255 Trinasmarts with the integral Tigos.  The folks at
Tigo insist the issue is not theirs and, given that either string works
fine by itself and both strings work fine when not in conduit, I tend to
believe them.  I just don't appreciate how having 20' of undamaged homerun
wire in conduit as opposed to free air can make an inverter stop
operating.

Thanks,

Matt



On Wed, September 7, 2016 8:58 pm, jay wrote:
> hate to ask the obvious here, but you mean to say that volts and
> polarity are correct on both sets of wires at the inverter when not
connected?
>
> and
>
> 2. what wattage modules are you using?
>
>
> jay peltz power
>
>
>
>
>
>
>
>
>> On Sep 7, 2016, at 2:45 PM, Matt Partymiller
>> <m...@solar-energy-solutions.com> wrote:
>>
>>
>> Wrenches,
>>
>>
>> One of our systems is having an issue I have not encountered before
>> where the inverter switches between nighttime mode and
>> interconnection every few seconds.  I am hoping for some technical
>> wisdom from the community.
>>
>> We have an array of 20 TrinaSmart modules in two strings of 10.  The
>> array is connected to a Solectria 3.8 kW inverter.  The conduit run
>> is simple, all four homerun wires (#10 PVwire) in 1" EMT down to the
>> proximity of the Solectria inverter where the conduit switches to 1"
>> LFMC before entering
>> the inverter.  The run is about 20', straight down the side of the
>> wall before hitting the inverter.  A 600V jacketed communications
>> wire was also in the conduit but has since been removed and run
separately.
>>
>> Our inverter is starting up, running for a few seconds, giving a low
>> voltage error, briefly showing nighttime mode, then going into
>> startup mode again.  Solectria was gracious enough to send us a new
>> inverter but we have the exact same issue.  They tell us their error
>> codes (266,
>> 274)
>> indicate 0 volts.  The transition between low voltage error and
>> startup is almost instant.  Basically we have 20 seconds of start up,
>> 5 seconds of run, 5 seconds of error then repeat.  This is not a grid
>> problem, the  identical system next door works fine.
>>
>> In the process of troublesh

Re: [RE-wrenches] Troubleshooting Stumper - Homerun Interference in Conduit/Inverter Turning Off/On Rapidly

[Matthew Sirum]

Greetings Matt,

I like the troubleshooting thoughts others have given.  If all else
leaves you with the issue persisting I would also consider checking
for current on the grounding system and on bonded conductive
materials/items on the property.  It may be helpful to see if there is
any current on the Equipment Grounding Conductors, Grounding Electrode
Conductor(s), metallic conduits & raceways, PV mounting system, and
etc.  If the inverter in this system has an AC Neutral connection
intended only for instrumentation and L1 & L2 voltage reference it
would be interesting to measure the actual current on it.  It is good
you have a similar system installed next door, you may need to compare
test measurements and readings.  If you run out of tests and
troubleshooting ideas it may be helpful to open (turn off) all the
circuits in the house/on the service and see how the PV system
performs while being the only item connected to the service.

The "smart" modules/optimizers may be making system troubleshooting
more challenging.  I wonder what Trina & Tigo has/can offer(ed) to
assist with troubleshooting?... and if there is an approved/safe
megger (insulation resistance) test for these modules?  This is an
interesting case.  I'll be continuing to follow the thread.  I hope we
can all learn something from this.

Best regards,

MATT

Matthew Sirum
P.O. Box 1227
Greenfield, MA 01302-1227  USA
phone: +1.413.773.0611
email: matthewsi...@gmail.com

Date: Wed, 7 Sep 2016 17:45:32 -0400
From: "Matt Partymiller" <m...@solar-energy-solutions.com>
To: re-wrenches@lists.re-wrenches.org
Subject: [RE-wrenches] Troubleshooting Stumper - Homerun Interference
in Conduit/Inverter Turning Off/On Rapidly

Wrenches,

One of our systems is having an issue I have not encountered before
where the inverter switches between nighttime mode and interconnection
every few seconds.  I am hoping for some technical wisdom from the
community.

We have an array of 20 TrinaSmart modules in two strings of 10.  The
array is connected to a Solectria 3.8 kW inverter.  The conduit run is
simple, all four homerun wires (#10 PVwire) in 1" EMT down to the
proximity of the Solectria inverter where the conduit switches to 1"
LFMC before entering the inverter.  The run is about 20', straight
down the side of the wall before hitting the inverter.  A 600V
jacketed communications wire was also in the conduit but has since
been removed and run separately.

Our inverter is starting up, running for a few seconds, giving a low
voltage error, briefly showing nighttime mode, then going into startup
mode again.  Solectria was gracious enough to send us a new inverter
but we have the exact same issue.  They tell us their error codes
(266, 274) indicate 0 volts.  The transition between low voltage error
and startup is almost instant.  Basically we have 20 seconds of start
up, 5 seconds of run, 5 seconds of error then repeat.  This is not a
grid problem, the identical system next door works fine.

In the process of troubleshooting, our technician pulled all four homerun
wires out of our conduit and meggered them.  They all tested fine so he
connected to the inverter.  The inverter worked fine.  The technician
verified grounding of the array and conduit, pulled new homeruns back
through the conduit, and reconnected to the inverter.  He had the same
error as before.

He connected each string separately to the inverter by removing the
string fuses.  Either string will operate fine independently.  With
string one in conduit and either homerun of string two in conduit (but
not both) the inverter operates fine.  With string two in conduit but
string one outside of conduit, the inverter does not operate.

I was certain the error had something to do with homerun roof wiring so I
went out with the technician and removed and checked pretty much every
module.  Everything appears fine, all connections solid, all homeruns
have been remade at least once at this point.  Now I am stumped and
lack the technical knowledge to diagnose the problem.  I would be
extremely grateful if an esteemed wrench can provide technical
support/advice.

Thanks,

Matt

Matthew Partymiller
Solar Energy Solutions LLC
(877) 312-7456
m...@solar-energy-solutions.com
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Re: [RE-wrenches] Troubleshooting Stumper - Homerun Interference in Conduit/Inverter Turning Off/On Rapidly

[Maverick Brown [Maverick Solar]]

"string two in conduit but string one outside of conduit, the inverter does
not operate"...

Maybe string two has a mild ground fault at the last module, positive side,
or at its internal diode. ???

Basically why can't string two operate in the conduit?



-Original Message-
From: RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] On
Behalf Of Matt Partymiller
Sent: Wednesday, September 07, 2016 4:46 PM
To: re-wrenches@lists.re-wrenches.org
Subject: [RE-wrenches] Troubleshooting Stumper - Homerun Interference in
Conduit/Inverter Turning Off/On Rapidly

Wrenches,

One of our systems is having an issue I have not encountered before where
the inverter switches between nighttime mode and interconnection every few
seconds.  I am hoping for some technical wisdom from the community.

We have an array of 20 TrinaSmart modules in two strings of 10.  The array
is connected to a Solectria 3.8 kW inverter.  The conduit run is simple, all
four homerun wires (#10 PVwire) in 1" EMT down to the proximity of the
Solectria inverter where the conduit switches to 1" LFMC before entering the
inverter.  The run is about 20', straight down the side of the wall before
hitting the inverter.  A 600V jacketed communications wire was also in the
conduit but has since been removed and run separately.

Our inverter is starting up, running for a few seconds, giving a low voltage
error, briefly showing nighttime mode, then going into startup mode again.
Solectria was gracious enough to send us a new inverter but we have the
exact same issue.  They tell us their error codes (266, 274) indicate 0
volts.  The transition between low voltage error and startup is almost
instant.  Basically we have 20 seconds of start up, 5 seconds of run, 5
seconds of error then repeat.  This is not a grid problem, the identical
system next door works fine.

In the process of troubleshooting, our technician pulled all four homerun
wires out of our conduit and meggered them.  They all tested fine so he
connected to the inverter.  The inverter worked fine.  The technician
verified grounding of the array and conduit, pulled new homeruns back
through the conduit, and reconnected to the inverter.  He had the same error
as before.

He connected each string separately to the inverter by removing the string
fuses.  Either string will operate fine independently.  With string one in
conduit and either homerun of string two in conduit (but not both) the
inverter operates fine.  With string two in conduit but string one outside
of conduit, the inverter does not operate.

I was certain the error had something to do with homerun roof wiring so I
went out with the technician and removed and checked pretty much every
module.  Everything appears fine, all connections solid, all homeruns have
been remade at least once at this point.  Now I am stumped and lack the
technical knowledge to diagnose the problem.  I would be extremely grateful
if an esteemed wrench can provide technical support/advice.

Thanks,

Matt




Matthew Partymiller
Solar Energy Solutions LLC
(877) 312-7456
m...@solar-energy-solutions.com


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Re: [RE-wrenches] Troubleshooting Stumper - Homerun Interference in Conduit/Inverter Turning Off/On Rapidly

[Lloyd Hoffstatter]

I was thinking the same, done with battery cables to reduce inductance,
Lloyd

Sent from my iPhone

On Sep 7, 2016, at 10:16 PM, 
"toddc...@finestplanet.com" 
> wrote:


im not sure why i am even suggesting this, but have you tried twisting the 
separate string's pairs before running them through the conduit?



todd










On Wednesday, September 7, 2016 6:55pm, "Matt Partymiller" 
> said:


> Thanks for all the questions and interest in my troubleshooting.
>
> The polarities are definitely correct. When testing wires at the inverter
> with the DC disco off and fuses pulled, we see correct voltage on each
> string.
>
> We have tried using two clamp meters to measure current on each string
> while operating the inverter with our homeruns in the conduit. Using the
> max function we never saw a meter get above about 1.5A (even less earlier
> in the day). String two seemed to be consistently lower but I really
> wasn't sure if that was an inverter function or not as it ramps up towards
> max power. With the homeruns outside of conduit the inverter operates
> fine and both strings show similar, but not identical, current. Doing the
> math it appeared each string was producing roughly half of inverter output
> at that time.
>
> To Jerry's question, the system did operate fine for about a week and 65
> kWh. The inverter then failed. Our technician replaced that inverter
> with a new Solectria 3.8 kW unit, restarted the unit, and noted the
> problem. With Solectria's help he arrived at the idea that we had a
> faulty inverter, got a new one in, and noted the exact same error codes
> and began trying to troubleshoot. He left the third inverter installed
> and also installed a new Tigo Cloud Connect and Gateway for the Trinasmart
> system.
>
> The modules are 255 Trinasmarts with the integral Tigos. The folks at
> Tigo insist the issue is not theirs and, given that either string works
> fine by itself and both strings work fine when not in conduit, I tend to
> believe them. I just don't appreciate how having 20' of undamaged homerun
> wire in conduit as opposed to free air can make an inverter stop
> operating.
>
> Thanks,
>
> Matt
>
>
>
> On Wed, September 7, 2016 8:58 pm, jay wrote:
> > hate to ask the obvious here, but you mean to say that volts and polarity
> > are correct on both sets of wires at the inverter when not connected?
> >
> > and
> >
> > 2. what wattage modules are you using?
> >
> >
> > jay peltz power
> >
> >
> >
> >
> >
> >
> >
> >
> >> On Sep 7, 2016, at 2:45 PM, Matt Partymiller
> >> > 
> >> wrote:
> >>
> >>
> >> Wrenches,
> >>
> >>
> >> One of our systems is having an issue I have not encountered before
> >> where the inverter switches between nighttime mode and interconnection
> >> every few seconds. I am hoping for some technical wisdom from the
> >> community.
> >>
> >> We have an array of 20 TrinaSmart modules in two strings of 10. The
> >> array is connected to a Solectria 3.8 kW inverter. The conduit run is
> >> simple, all four homerun wires (#10 PVwire) in 1" EMT down to the
> >> proximity of the Solectria inverter where the conduit switches to 1"
> >> LFMC before entering
> >> the inverter. The run is about 20', straight down the side of the wall
> >> before hitting the inverter. A 600V jacketed communications wire was
> >> also in the conduit but has since been removed and run separately.
> >>
> >> Our inverter is starting up, running for a few seconds, giving a low
> >> voltage error, briefly showing nighttime mode, then going into startup
> >> mode again. Solectria was gracious enough to send us a new inverter
> >> but we have the exact same issue. They tell us their error codes (266,
> >> 274)
> >> indicate 0 volts. The transition between low voltage error and startup
> >> is almost instant. Basically we have 20 seconds of start up, 5 seconds
> >> of run, 5 seconds of error then repeat. This is not a grid problem, the
> >> identical system next door works fine.
> >>
> >> In the process of troubleshooting, our technician pulled all four
> >> homerun wires out of our conduit and meggered them. They all tested
> >> fine so he connected to the inverter. The inverter worked fine. The
> >> technician verified grounding of the array and conduit, pulled new
> >> homeruns back through the conduit, and reconnected to the inverter. He
> >> had the same error as before.
> >>
> >> He connected each string separately to the inverter by removing the
> >> string fuses. Either string will operate fine independently. With
> >> string one in conduit and either homerun of string two in conduit (but
> >> not both) the inverter operates fine. With string two in conduit but
> >> string one outside of conduit, the inverter does not operate.
> >>
> >> I was certain 

Re: [RE-wrenches] Troubleshooting Stumper - Homerun Interference in Conduit/Inverter Turning Off/On Rapidly

[toddcory]

im not sure why i am even suggesting this, but have you tried twisting the 
separate string's pairs before running them through the conduit?
 
todd
 
 
 
 


On Wednesday, September 7, 2016 6:55pm, "Matt Partymiller" 
 said:



> Thanks for all the questions and interest in my troubleshooting.
> 
> The polarities are definitely correct. When testing wires at the inverter
> with the DC disco off and fuses pulled, we see correct voltage on each
> string.
> 
> We have tried using two clamp meters to measure current on each string
> while operating the inverter with our homeruns in the conduit. Using the
> max function we never saw a meter get above about 1.5A (even less earlier
> in the day). String two seemed to be consistently lower but I really
> wasn't sure if that was an inverter function or not as it ramps up towards
> max power. With the homeruns outside of conduit the inverter operates
> fine and both strings show similar, but not identical, current. Doing the
> math it appeared each string was producing roughly half of inverter output
> at that time.
> 
> To Jerry's question, the system did operate fine for about a week and 65
> kWh. The inverter then failed. Our technician replaced that inverter
> with a new Solectria 3.8 kW unit, restarted the unit, and noted the
> problem. With Solectria's help he arrived at the idea that we had a
> faulty inverter, got a new one in, and noted the exact same error codes
> and began trying to troubleshoot. He left the third inverter installed
> and also installed a new Tigo Cloud Connect and Gateway for the Trinasmart
> system.
> 
> The modules are 255 Trinasmarts with the integral Tigos. The folks at
> Tigo insist the issue is not theirs and, given that either string works
> fine by itself and both strings work fine when not in conduit, I tend to
> believe them. I just don't appreciate how having 20' of undamaged homerun
> wire in conduit as opposed to free air can make an inverter stop
> operating.
> 
> Thanks,
> 
> Matt
> 
> 
> 
> On Wed, September 7, 2016 8:58 pm, jay wrote:
> > hate to ask the obvious here, but you mean to say that volts and polarity
> > are correct on both sets of wires at the inverter when not connected?
> >
> > and
> >
> > 2. what wattage modules are you using?
> >
> >
> > jay peltz power
> >
> >
> >
> >
> >
> >
> >
> >
> >> On Sep 7, 2016, at 2:45 PM, Matt Partymiller
> >>  wrote:
> >>
> >>
> >> Wrenches,
> >>
> >>
> >> One of our systems is having an issue I have not encountered before
> >> where the inverter switches between nighttime mode and interconnection
> >> every few seconds. I am hoping for some technical wisdom from the
> >> community.
> >>
> >> We have an array of 20 TrinaSmart modules in two strings of 10. The
> >> array is connected to a Solectria 3.8 kW inverter. The conduit run is
> >> simple, all four homerun wires (#10 PVwire) in 1" EMT down to the
> >> proximity of the Solectria inverter where the conduit switches to 1"
> >> LFMC before entering
> >> the inverter. The run is about 20', straight down the side of the wall
> >> before hitting the inverter. A 600V jacketed communications wire was
> >> also in the conduit but has since been removed and run separately.
> >>
> >> Our inverter is starting up, running for a few seconds, giving a low
> >> voltage error, briefly showing nighttime mode, then going into startup
> >> mode again. Solectria was gracious enough to send us a new inverter
> >> but we have the exact same issue. They tell us their error codes (266,
> >> 274)
> >> indicate 0 volts. The transition between low voltage error and startup
> >> is almost instant. Basically we have 20 seconds of start up, 5 seconds
> >> of run, 5 seconds of error then repeat. This is not a grid problem, the
> >> identical system next door works fine.
> >>
> >> In the process of troubleshooting, our technician pulled all four
> >> homerun wires out of our conduit and meggered them. They all tested
> >> fine so he connected to the inverter. The inverter worked fine. The
> >> technician verified grounding of the array and conduit, pulled new
> >> homeruns back through the conduit, and reconnected to the inverter. He
> >> had the same error as before.
> >>
> >> He connected each string separately to the inverter by removing the
> >> string fuses. Either string will operate fine independently. With
> >> string one in conduit and either homerun of string two in conduit (but
> >> not both) the inverter operates fine. With string two in conduit but
> >> string one outside of conduit, the inverter does not operate.
> >>
> >> I was certain the error had something to do with homerun roof wiring so
> >> I
> >> went out with the technician and removed and checked pretty much every
> >> module. Everything appears fine, all connections solid, all homeruns
> >> have been remade at least once at this point. Now I am stumped and lack
> >> the technical knowledge to diagnose the 

Re: [RE-wrenches] Troubleshooting Stumper - Homerun Interference in Conduit/Inverter Turning Off/On Rapidly

[August Goers]

Definitely check polarity on each string. Could be positives and negatives
are mixed up and the wire colors are adding to the confusion.



August





*From:* RE-wrenches [mailto:re-wrenches-boun...@lists.re-wrenches.org] *On
Behalf Of *Roy Rakobitsch
*Sent:* Wednesday, September 07, 2016 3:35 PM
*To:* RE-wrenches
*Subject:* Re: [RE-wrenches] Troubleshooting Stumper - Homerun Interference
in Conduit/Inverter Turning Off/On Rapidly



Have you measured the current of each string simultaneously while the issue
was happening? Have you verified correct polarity on each string?

Roy Rakobitsch
NABCEP Certified Small Wind Installer®
Certified Advanced Tower Climbing, Safety & Rescue
Wind/PV Design Engineer
Windsine LLC
631-514-4166
www.windsine.org



On Sep 7, 2016 4:45 PM, "Matt Partymiller" <m...@solar-energy-solutions.com>
wrote:

Wrenches,

One of our systems is having an issue I have not encountered before where
the inverter switches between nighttime mode and interconnection every few
seconds.  I am hoping for some technical wisdom from the community.

We have an array of 20 TrinaSmart modules in two strings of 10.  The array
is connected to a Solectria 3.8 kW inverter.  The conduit run is simple,
all four homerun wires (#10 PVwire) in 1" EMT down to the proximity of the
Solectria inverter where the conduit switches to 1" LFMC before entering
the inverter.  The run is about 20', straight down the side of the wall
before hitting the inverter.  A 600V jacketed communications wire was also
in the conduit but has since been removed and run separately.

Our inverter is starting up, running for a few seconds, giving a low
voltage error, briefly showing nighttime mode, then going into startup
mode again.  Solectria was gracious enough to send us a new inverter but
we have the exact same issue.  They tell us their error codes (266, 274)
indicate 0 volts.  The transition between low voltage error and startup is
almost instant.  Basically we have 20 seconds of start up, 5 seconds of
run, 5 seconds of error then repeat.  This is not a grid problem, the
identical system next door works fine.

In the process of troubleshooting, our technician pulled all four homerun
wires out of our conduit and meggered them.  They all tested fine so he
connected to the inverter.  The inverter worked fine.  The technician
verified grounding of the array and conduit, pulled new homeruns back
through the conduit, and reconnected to the inverter.  He had the same
error as before.

He connected each string separately to the inverter by removing the string
fuses.  Either string will operate fine independently.  With string one in
conduit and either homerun of string two in conduit (but not both) the
inverter operates fine.  With string two in conduit but string one outside
of conduit, the inverter does not operate.

I was certain the error had something to do with homerun roof wiring so I
went out with the technician and removed and checked pretty much every
module.  Everything appears fine, all connections solid, all homeruns have
been remade at least once at this point.  Now I am stumped and lack the
technical knowledge to diagnose the problem.  I would be extremely
grateful if an esteemed wrench can provide technical support/advice.

Thanks,

Matt




Matthew Partymiller
Solar Energy Solutions LLC
(877) 312-7456
m...@solar-energy-solutions.com


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Re: [RE-wrenches] Troubleshooting Stumper - Homerun Interference in Conduit/Inverter Turning Off/On Rapidly

[Roy Rakobitsch]

Have you measured the current of each string simultaneously while the issue
was happening? Have you verified correct polarity on each string?

Roy Rakobitsch
NABCEP Certified Small Wind Installer®
Certified Advanced Tower Climbing, Safety & Rescue
Wind/PV Design Engineer
Windsine LLC
631-514-4166
www.windsine.org

On Sep 7, 2016 4:45 PM, "Matt Partymiller" 
wrote:

> Wrenches,
>
> One of our systems is having an issue I have not encountered before where
> the inverter switches between nighttime mode and interconnection every few
> seconds.  I am hoping for some technical wisdom from the community.
>
> We have an array of 20 TrinaSmart modules in two strings of 10.  The array
> is connected to a Solectria 3.8 kW inverter.  The conduit run is simple,
> all four homerun wires (#10 PVwire) in 1" EMT down to the proximity of the
> Solectria inverter where the conduit switches to 1" LFMC before entering
> the inverter.  The run is about 20', straight down the side of the wall
> before hitting the inverter.  A 600V jacketed communications wire was also
> in the conduit but has since been removed and run separately.
>
> Our inverter is starting up, running for a few seconds, giving a low
> voltage error, briefly showing nighttime mode, then going into startup
> mode again.  Solectria was gracious enough to send us a new inverter but
> we have the exact same issue.  They tell us their error codes (266, 274)
> indicate 0 volts.  The transition between low voltage error and startup is
> almost instant.  Basically we have 20 seconds of start up, 5 seconds of
> run, 5 seconds of error then repeat.  This is not a grid problem, the
> identical system next door works fine.
>
> In the process of troubleshooting, our technician pulled all four homerun
> wires out of our conduit and meggered them.  They all tested fine so he
> connected to the inverter.  The inverter worked fine.  The technician
> verified grounding of the array and conduit, pulled new homeruns back
> through the conduit, and reconnected to the inverter.  He had the same
> error as before.
>
> He connected each string separately to the inverter by removing the string
> fuses.  Either string will operate fine independently.  With string one in
> conduit and either homerun of string two in conduit (but not both) the
> inverter operates fine.  With string two in conduit but string one outside
> of conduit, the inverter does not operate.
>
> I was certain the error had something to do with homerun roof wiring so I
> went out with the technician and removed and checked pretty much every
> module.  Everything appears fine, all connections solid, all homeruns have
> been remade at least once at this point.  Now I am stumped and lack the
> technical knowledge to diagnose the problem.  I would be extremely
> grateful if an esteemed wrench can provide technical support/advice.
>
> Thanks,
>
> Matt
>
>
>
>
> Matthew Partymiller
> Solar Energy Solutions LLC
> (877) 312-7456
> m...@solar-energy-solutions.com
>
>
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