Please correct me if I'm wrong, but to summarize this issue:
1) code requires clockwise phase rotation in Panel boards, and AC disconnects,
2) even though it's not code required, it is good practice to tape those wires
black, red, blue, again left to right or clockwise. (as long as you're in the
Little beyond a pair of Outbacks, possibly a pair of Magnasine inverters, or a
quad stack of Outbacks.
R. Walters
r...@solarray.com
Solar Engineer
On Aug 26, 2010, at 2:41 PM, Joel Davidson wrote:
> Wrenches,
> Our customer has a fire protection pumping system that operates at 240VAC and
>
3:52 PM, R Ray Walters wrote:
> Little beyond a pair of Outbacks, possibly a pair of Magnasine inverters, or
> a quad stack of Outbacks.
>
> R. Walters
> r...@solarray.com
> Solar Engineer
>
>
>
>
> On Aug 26, 2010, at 2:41 PM, Joel Davidson wrote:
>
>
To: "RE-wrenches"
>> Date: Friday, August 27, 2010, 9:50 PM
>> Hi Ray,
>>
>> Thank you for your input. The pump is part of a fire
>> protection system that sucks water out of the swimming pool
>> and pumps it to roof sprinklers with fire retardant
Oh boy, just when we thought all we had to worry about was getting electrocuted
or falling off a roof.
The cooked dummy at the end of the last video is a very serious reminder.
Besides the arc flash gear, are there other things we should be watching for to
prevent this from happening? (we definit
I know, as Bill pointed out, that the Deltas are supposed to be mounted on the
exterior to allow the damage to stay outside of the combiner box. But I've also
seen a lot of old Deltas damaged by the sun, and seen them cracked off at the
1/2" nipple attachment point, which then leaves exposed THH
If its a large commercial array, I would consider using larger centralized
inverters, and then monitor with National Semiconductor's Solar magic
monitoring system. It has string level current taps, so (theoretically at
least) you could see a single module failure by the reduced string output.
I
I've used the Pathfinder for decades, so I'm partial to them. Great for on-site
discussions of shading issues with the customer, as multiple people can see the
shading at the same time on the spot.
I've also used their Assistant software, and it works pretty well. You take a
photo of the actual
The problem with all shading analysis tools I've used, is that they can't take
into account the effects partial shading has on string performance. You have to
calculate that separately, based on how you'll be wiring the strings.
2nd, I know that usually power lines (if far enough away) won't have
The nice folks at BZ Products have made me small custom voltage controllers
before, for just that application.
Prices, as I recall were less than a C40, and much smaller footprint/ weight,
which is an issue on a mobile application.
R. Walters
r...@solarray.com
Solar Engineer
On Sep 10, 2010
eally want a sealed unit as this will be on
> a vehicle and possibly get wet.
>
> thx,
>
> jay
>
> Peltz Power
>
>
> On Sep 11, 2010, at 7:45 PM, R Ray Walters wrote:
>
>> The nice folks at BZ Products have made me small custom voltage controllers
>
A picture is worth a thousand words, (hopefully this will upload)
Here's a traditional Ilsco Lug after less than 5 years near the ocean:
<>
IMHO, this is a galvanic reaction between the Cu, Al, and (our loser) the Lug
which became the anode.
No other corrosion was near this state of deterioration
;
> Peter T. Parrish, Ph.D., President
> California Solar Engineering, Inc.
> 820 Cynthia Ave., Los Angeles, CA 90065
> CA Lic. 854779, NABCEP Cert. 031806-26
> peter.parr...@calsolareng.com
> Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885
>
>
>
> -Original Mes
cking plate.
Is this also a voltage issue, for arrays over 250 v?
I'm sure I'm missing something.
I recall you once saying that UL doesn't even use the grounding hole when
testing modules, that they just clamped an alligator clip to the frame?
Thanks for giving us the "NEC and
September 12, 2010 6:50 pm
> To: "'RE-wrenches'"
>
> Are you sure that's a ILSCO GBL-4DBT lug? I am pretty sure the set screw is
> not SS, which it should be to be the genuine part.
>
> - Peter
>
>
> Peter T. Parrish, Ph.D., President
> Ca
Maybe this should be on the NABCEP test.
R. Walters
On Sep 13, 2010, at 8:04 PM, benn kilburn wrote:
> Hopefully any crew installing PV, and familiar with this debate (which they
> should be) can easily distinguish between the GBL-4 and the GBL-4DBT. The
> weight difference is quite noticeabl
You could buy several ground rods for the cost of one Delta.
Ground Impedance is the real issue. Both the Delta and the Polyphasor need a
good ground to work.
While I haven't seen much of a correlation between Deltas and reduced lightning
damage, (lots of system damage with and without)
I have fo
HI BIll;
I'm still slightly confused:
I think you are saying that the #8 can go straight to the service panel
grounding buss? (as per 690.47(C)6&8)
What about 690.47 (D) that requires an array ground to go to a supplemental
electrode installed "as close as practicable to the array."
For
It seems to me that William's original question of where does the EGC stop, and
the GEC begin, all depends on whether the Enphase inverters bond negative to
ground internally.
Did we ever get an answer from Enphase?
If they don't, then I think by definition in article 100, we would only have an
My own limited field experience in lightning country (New Mexico, Colorado,
Wyoming, Texas, Oklahoma), has definitely proven your point. Grounding and
testing of the grounding system is the first line of attack against lightning.
Also, showing an insurance company (and the customer) ground impeda
grid
measurements.
R. Walters
On Sep 14, 2010, at 8:04 PM, Dave Palumbo wrote:
> What Ray Walters said was the truth. Resistance to ground should be very low.
> How many dollars is that tester you use Ray? We don’t own one. On the wish
ween them? Also what is the lowest Ohm reading your DGC
> 1000 meter can read?
> Thanks
>
> --- On Wed, 9/15/10, R Ray Walters wrote:
>
> From: R Ray Walters
> Subject: Re: [RE-wrenches] Lightning protection (was Delta LA's)
> To: "RE-wrenches"
>
HI Allan;
I found the 175s play very well when mixed with the 165s on an MX 60. We've
done it several times.
What's interesting is that the Solarworlds often outperform their nameplate
rating, I've seen the 165s close to the 175 numbers.
Essentially they're all the same module, just flash tests
I agree Nick, that's what the wrenches list is for: to protect our fellow
wrenches and our customers. If Solar CIty is taking the business, they better
be able to take the heat. I'm very concerned that they are not hiring
experienced designers. They're about to give the whole industry a black ey
At one point at the top, he has both hands free, while he messes with the
lanyard. At another point he "ties off" by just hooking the lanyard to the
ladder rung, but its open on the side, allowing the hook to slide off the end.
I'm glad you let us know that was "not an approved climbing method".
I take the generator concern one step further:
We had a "solar dealer" selling Y2K generator specials that included a Male to
Male extension cord!
Just plug that bad boy into any outlet and fire the whole place (and the
utility line) up.
I confiscated one of these cables, and show it to new inspe
My long field experience with Solarworld modules measured in conjunction with
an irradiance meter, shows that they do consistently out perform their STC
ratings.
Of course that's not a "take it to the bank" lab test. I've also seen Sunpower
outperform its STC ratings.
R. Walters
r...@solarray.c
I still haven't found a substitute for the venerable SW series inverters from
Trace/ Xantrex/ Schneider?.
Even after the Outback inverters came out, I still used the SWs for autostart
projects. Otherwise it was just too much hassle.
90% of my generator projects,though, I talked the customer into
was under the
impression that they had to have positive bonded to ground to function
properly. Your proposed "Temporary Ground Lift" circuit would probably be the
best way for Sunpower modules?
Thanks for your always thorough education of us numb nuts in the field,
Ray Walters
>
I can confirm at least one reverse marked battery as well; another reason I
hammer everyone on my projects to confirm polarity with a multimeter, and mark
the wires as John Wiles has advocated:
Red = Positive, Black = negative for ungrounded systems
Red = positive, white = negative for neg ground
Corrugated is really a pain to flash, but the ProPanel type roofing is really
easy to work with. It has large (6 to 8"? wide) sections to put mounting feet
down on.
Only problem is if the rafter you need, ends up falling under a metal ridge.
Snow slides off metal roofs all at once in big clumps,
rounded. This solves SunPower polarization issue and is the way many of
> their systems are installed in Europe.
>
> Bill.
>
> From: re-wrenches-boun...@lists.re-wrenches.org
> [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of R Ray Walters
> Sent: Tuesday, Oc
Hi Jay;
I'd second (3rd, 4th?) everyone else's comments that it probably isn't a good
idea.
I'd add that the diode will eat at least a volt, so that's not good for MPPT,
or balancing.
The one possible way to do this, might be to use a Vanner battery equalizer,
which is designed to split an inco
;>
>> the client may be willing to try and see how it goes with the controllers,
>> at this point hes aware that it could blow up and its not a warranty issue.
>>
>> Will keep you up to date about what smokes or not.
>>
>> j
>>
>> peltz power
&g
Why does the side mounted breakers make the Midnite non compliant?
Apparently I missed Robin's post on that.
Or do I not want to know?
Thanks,
R. Walters
r...@solarray.com
Solar Engineer
> . Midnite enclosures, with the breakers on the sides, are not compliant, as
> Robin has acknowledged, but
I agree with Phil's always excellent posts, except for the quote below.
> On Oct 21, 2010, at 9:29 PM, Phil Undercuffler wrote:
>
>> risk splitting the top chord of the beam. If you split that, I would
>> immediately stop what you're doing and consult with the I-beam manufacturer.
>> Big lia
Hi Nathan;
I agree that too many strings can cause problems, as you mentioned, but I've
seen 2 major problems with single battery strings, too:
1) A single cell failure, or corroded connection takes the entire system out of
commission.
2) Most batteries do not have enough current to meet the s
How is the CD version for 2008? Is it easier to look stuff up (ie indexed
better)?
I've never tried anything but the hard copies.
R. Walters
r...@solarray.com
Solar Engineer
On Oct 25, 2010, at 12:06 PM, Matt Lafferty wrote:
> Hi Drake,
>
> 2011 NEC is available now in Looseleaf (3-Ring bin
I've worked on a couple of commercial projects where birds were trouble. On
one, we would clean the array, and in less than a week, it would have crap all
over it. Definitely dropped output.
An owl decoy seemed to not have much effect.
On another project, they had installed the high frequency sou
HI Allan;
I just recently used some flexible stainless steel line on an old radiator/
boiler system here. It had special fittings, that I was a little dubious of at
first, but it all worked well, and was easy to install.
I believe it was the Easy flex product.
The only problem I encountered, was
The large batteries as everyone else noted are definitely the way to go on off
grid systems.
You are strengthening the weakest link. However, consider 2 parallel strings.
I no longer consider a single string to be optimum, after having a large pump
on a pair of Outback inverters cause low volta
Nick;
How many of the failures are polycrystalline vs. mono?
Both Solarex (then later BP) had failures of their poly stuff, are those the
ones you are referring too?
Photowatt comes to mind
I've had my best luck though with the Made in USA monocrystalline.
R. Walters
r...@solarray.com
Solar
I've seen inverters do just fine under construction of the house. As long as it
isn't being overloaded every day.
As for bad connections, if the main DC connects aren't tight, you can get
enough heat to melt the plastic insulators, and then it can short to the case.
I can send you an ugly picture
C40 charge controllers used to have that problem too; if battery voltage
dropped so low that it didn't think it had a battery to charge, the whole
system just sits there crashed, batteries sulfating, sun shining(customer
stewing)
I'd just charge them on a 12 v automotive charger, 2 at a
I'd just be worried about the rebar blowing the plaster out, when it comes out
the other side.
We welded a drill bit to the end of the rebar.
Once we're through with our rebar/ bit thing, we use diamond grit hole saws to
make a clean hole in the plaster.
I've been eyeing the Lenox carbide hole s
HI Allan;
I converted years ago to a single clip-on leather pouch from Texas hold um.
This one pouch holds my needle nose, 9" line's man pliers, wire stripper/
crimper, 10" channel locks, dike cutter, utility knife, mini screw driver, and
the Klein multi-tip screw driver.
I found walking around
HI All;
I have struggled for years to get the right battery cable; in the old, old days
we used welding cable, which was better than THHN, but not with the AHJs.
Then we used a SAE battery cable with 532 strands that was ideal, but not UL
listed.
Next we used Cobra X flex, but at over 2000 stran
1 THHN to
> go up into the SI batt terminals (two conductors per pole).
>
> In fact, I am wrapping up one of these installs right now.
>
> Don’t know if this helps,
>
> -Glenn
>
> -Original Message-
> From: re-wrenches-boun...@lists.re-wrenches.org
&g
HI Mark;
Where do you get the lead plated lugs? We used to special order tin plated lugs
from Del City, but they quit carrying them.
I found that the grease or vaseline coating was the most important issue,
though. Tin plated lugs would corrode just like the unplated ones, except they
first wou
ulation on motor windings and frames. Sprays are available in
> clear, red or black.”
>
> The local Home Depot carries it here, also some electrical distributors.
>
>
> From: R Ray Walters
> Sent: Tuesday, November 30, 2010 9:26 AM
> To: RE-wrenches
> Subject: Re: [RE-
One AHJ actually got me on this with sealed batteries. I've blown the seal out
overcharging a sealed battery too, so this is a real possibility. The venting
requirements are not near as stringent though as for a flooded cell. Article
480 says we need to prevent the build up of explosive gases, w
I'll agree with you, Dana, although I think setting the batteries in the ground
will help in more of the cases.
Battery optimum temperature is actually lower than the standard test temp of
25C (77F).
When you overlay the graph showing increased cycle life of batteries at lower
temps with the ca
I really think the real venting issue is H2S (hydrogen sulfide) gas, which is
deadly at high enough concentrations, causes head aches at lower
concentrations, and is just awful to smell at any concentration.
I think you would have to literally design a battery box to explode to ever get
to the 4
(888) ON-SOLAR (US only) FAX: (530) 273-1760
> e-mail: <mailto:solar...@sierrasolar.com>
> world wide web: <http://www.sierrasolar.com>
>
>
> On Dec 15, 2010, at 10:48 AM, R Ray Walters wrote:
>
>> I really think the real venting issue is H2S (hydrogen su
I had so much trouble EQing with the SWs, that I just told the customers to
bulk charge in the early AM with the genie, and then use the PV in the
afternoon to reach EQ voltage, or temporarily set the bulk voltage higher in
the normal SW charge mode to EQ.
We don't EQ as much as some (twice a ye
Hey Chris;
Thanks for the link, they have a charger I've been looking for for a long time:
a selectable voltage portable unit. Front switch lets you select 24, 36, or 48
volt battery.
R. Walters
r...@solarray.com
Solar Engineer
On Dec 28, 2010, at 11:13 AM, Chris Schaefer wrote:
> Larry,
>
Jay;
I've saved a few sets from freezing, different manufacturers' cases are
stronger than others. (ie, A Trojan T105 can take more stress than something
from Sam's Club.)
FIrst I make sure they're less than 5 years old.
Then, I warm them backup (portable propane heater, very well vented area, n
I use volt drop under load, to find loose/ problem connections, but 2/100 of a
volt drop could just be due to the resistance between his probes and the
battery terminal.
DId he take 3 to 5 readings, and then avg his readings to come up with his
evaluation?
If his reading was accurate, a .02 v
I forgot to mention that an infared camera is a great way to find poor
connections.
Its a proven method on commercial panels, and I think it would work great for
battery cabling too.
Just put the system under full load for a few minutes, and the hot connections
would show up quick.
(of course j
I got my soft copy of NEC2011 at my electrical supply house for much cheaper
than retail, and it came with a code to download the PDF version from online.
I now have both, (searchable/ printable is great) but I don't know if I could
burn it to a CD.
R. Walters
r...@solarray.com
Solar Engineer
We've taken many of these on over the years: it can have a satisfying outcome,
if the customer is really willing to pay to fix it.
We don't even try to work with what's there; everything comes off the wall, and
we rebuild the whole system using any decent parts that can be reused.
Most customers
The Yamaha 2800 inverter generator is also a good choice, but only for small
systems. I found them an ideal match for the mod sine DR inverters (especially
the DR1500s)
I've done a couple of propane conversions to these, but I can't recommend it.
Worked fine, just by the time you're done, it is
FIrst, if they're intertied with the rest of the US grid, they already have
some of that Pesky wind and solar power on their grid.
Seems to me that just some good old load data would show the PV output would
never exceed the minimum daytime onsite usage.
I'm guessing you would want to look at wee
Excellent post Mark. We spend way too much time as an industry worrying about
these mundane grounding (and over grounding) issues, when there are very little
actual safety issues involved.
Meanwhile, we're missing the real safety problems. (recent commercial system
fires??)
I can't wait for our
From the bit of aluminum welding I've done (MIG not the preferred TIG) I'd say
it would be pretty hard to do without damaging the laminate.
I actually successfully welded attachments to salvage modules back in the 90s.
Also the alloys are probably different between the module and rail, so even if
HI BIll;
I follow you NEC logic here, and just needed a couple of clarifications:
1) Can we use smaller than #6 bare to connect to the inverters, as long as it
was not exposed to physical damage? (ie. under the modules, in conduit)
2) for irreversible splices, are crimp lugs acceptable, or do we
Hi Daryl;
DId you AC couple it to the Outback AC output? or did you use the AC in on the
Outback?
I liked the little 1 Kw Yamahas for battery charging, but they are so small
that if any loads come on in the house, the pass through loads will trip the
Yamaha's overload circuit, and quit charging
y
> house, replacing a Honda 2000i and sure do miss the fuel efficiency.
>
>
> -Original Message-
> From: R Ray Walters
> To: RE-wrenches
> Sent: Wed, Mar 16, 2011 4:46 pm
> Subject: Re: [RE-wrenches] Generators?
>
> Hi Daryl;
>
> DId you AC couple
Hi Drake;
No, I don't have answers, just more of your same concerns. I had a high
altitude (12,500 ft) installation damaged recently, possibly by a solar flare
in Feb; we lost a C40 charge controller.
At this point, I don't know if the flare was the cause or not, but I would
expect more proble
ional
> New Mexico EE98J Journeyman Electrician
> Positive Energy, Inc.
> 3201 Calle Marie
> Santa Fe, New Mexico 87507
> 505 424-1112
> www.positiveenergysolar.com
>
>
>
>
> On 3/19/2011 11:48 AM, R Ray Walters wrote:
>>
>> Hi Drake;
>>
>> No,
I designed a pole mount for the US Forest Service that was 20 ft out of the
ground. Its basically telescoping sections of pipe, welded together. The base
was 8" Sch 80 for 10 ft, then 6" diam, and finished the last 6 ft in 4" diam.
We used a massive footing with lots of rebar that was 8 ft below
I 2nd William's comment: the anti-seize is especially important on stainless
bolts bigger than 1/4". The spalling effect with larger SS hardware has caused
me to return to regular plated hardware, if the project isn't near the ocean,
and just use SS washers when in contact with Aluminum.
Having
Personally, on grid or off, I like battery powered clocks. One 2 sec outage,
and the clock gets reset. I tend to use the clock on my cell phone and computer
mostly (automatic updates),
My battery powered weather station even has a clock that is linked to the
atomic clock system.
I've actually
Interesting that it seems the industry is moving back to L-feet and sealant?
Always worked for many situations.
R. Walters
r...@solarray.com
Solar Engineer
On Apr 7, 2011, at 7:11 PM, Andrew Truitt wrote:
>
> Here's the VersaBracket option from S-5!:
>
> http://www.s-5.com/clamps/index_71
I've been running Parallels on a Mac for 3 years, and I just bought a PC for
the PC stuff. I like my Mac, but after waiting 1/2 an hour to boot and update
everything each time, Parallels is just really clunky.
I like Omnigraffle on my Mac. way better than simpler drawing programs, but not
near a
Hi Rich;
1) I never had a problem with conduit and frost heave, but then again, I
haven't dug up all my work after 10 years either.
2) We did a mount exactly as you described, large slab with rebar into the rock
at 45s, and bolt the pole to j bolts in the concrete.
I can share our design drawing
Sunpower's modules with integral ballast are my current favorite for flat roof
mounts. We make our own skid frames for ballasted ground mounts.
R. Walters
r...@solarray.com
Solar Engineer
On Apr 16, 2011, at 9:38 PM, Nick Vida wrote:
> hey wrenches.
>
> i am looking at some ballasted racks.
I like the fused parallel idea; could save the system, and would make battery
troubleshooting nice.
I would suggest #6 jumpers with 50 to 60 amp breakers, so the system could be
operated on just a few strings if needed.
R. Walters
r...@solarray.com
Solar Engineer
On Apr 19, 2011, at 8:29 PM
lete failure I
> got the message pretty quick.
>
> Really guys, this is amazingly simple and yes, it may mean a bit more cabling
> and another component but from a safety standpoint those considerations are
> pretty minor and cheap insurance against disaster.
>
> Tom
>
Sounds like problem connections, if all the cells are an even 2.12 v.
I wouldn't solder 4/0 connections, the solder can run back up the cable
stranding, and make the cables too stiff to fully connect with the battery
terminal.
I had a battery terminal meltdown due to this. We quit using thick b
BCEP Certified Photovoltaic Installer
> NABCEP Certified Technical Sales Professional
> New Mexico EE98J Journeyman Electrician
> Positive Energy, Inc.
> 3201 Calle Marie
> Santa Fe, New Mexico 87507
> 505 424-1112
> www.positiveenergysolar.com
>
>
>
>
> On 4/20
At least with a breaker arrangement you could charge different strings
separately which would help an otherwise bad situation.
Also, I think the CB breakers would be adequate in this case. They have a 5000
AIC (too low for a HUP) but my specs on an AGM battery are showing 2300A short
circuit.
R
I recall Bill Brooks noting that the ILSOC ground lugs needed full contact of
their back surface with the surface it was mounted to. He was recommending
grinding off the oxide coating on the module around the screw hole to achieve
the desired contact. Apparently putting a star washer between the
Are you using temperature compensation? It lowers the voltage when its hot.
Also, have you considered setting the batteries in a below ground vault? I've
had good luck with in floor battery boxes.
Finally, AGMs and L16s just don't last very long anyway. AGMs maybe 3 years,
and L16s I've seen die
g all at about the same age.
>
> Thanks for your reply.
>
> Larry
> - Original Message -
> From: R Ray Walters
> To: RE-wrenches
> Sent: Thursday, April 21, 2011 1:50 PM
> Subject: Re: [RE-wrenches] Air conditioning for batteies in high
> temperatureclimate
>
>
Solarfest in Taos had a solar powered stage for years, so it definitely can be
done. I've been into sound stuff lately, and I can say the loads are extremely
variable.
I have a 600 watt rated amp, (class D design) that I peaked at 270 watts input
and averaged about 150 watts while I was testing
Dan;
Your system sounds great. I'd love to hear it sometime.
Just one question: how come no tube amps?
You're going to have some guitar players screaming; most of the best guitar
amps are all tube these days.
I know they waste a lot of power, but they're usually small compared to the PA
system.
Midnite Solar is now making Combiner boxes that are prewired with MC connects.
Being UL listed, I think they would speed both the installation and inspection
processes.
http://www.midnitesolar.com/products.php?menuItem=products&productCat_ID=9&productCatName=PV%20Combiners
They may also sell th
As I understand it, OSHA regs don't require you to purchase a certain product.
We built our own bases (2x4s, and saw horses, etc) and weighted them with extra
ballast blocks from the PV ballasting. We also used a regular rope with the
required strength, and hung warning flagging along with it.
T
I've grid tied a few battery based turbines now, both the 403 and Bergey XL1.
You can use a very small sealed battery (180 AH @ 24v), so that would take care
of the maintenance issue.
Cost on the other hand doesn't make sense, unless they want some emergency
backup capability.
If they don't want
Bob-O;
I was going to hold off on the obvious
I think they're also good as a bird repellant, noise maker, etc. but I've never
seen one actually make over 175 watts, and that was a 1 sec burst in strong
wind. SWWP always said the low output was due to the thinner air at high
altitude, but th
Even a bad solar installer isn't going to use cut up extension cords; that
install was DIY or a "knowledgable" inebriated neighbor. I lived in the
backwoods for many years, and saw even my own work get turned into horror
systems.
As far as your competitor doing bad work, we had the same problem
My experience is that parallel jumpers need to be equal. Also, if running
parallel strings, then the series jumpers would need to be equal to the wiring
path of the other parallel string.
I've actually added extra cable length, so that all parallel strings would
truly be equal.
On a single seri
If you wouldn't mind Peter, I'd like to see this discussion stay on the list.
I'd be interested to learn more about the actual anti-islanding features of
inverters.
What you've described seems to just cover the voltage and frequency windows
that the inverter will grid tie to.
I was always under t
We had an early 90s system with a DCGFP(complete with 4/0 GEC:)). A ground
fault on a DC load circuit caused the GFP to lift the ground, shut the array
off, but the short was still being fed by the battery and wouldn't trip the DC
breaker, since negative was disconnected from ground. I thought
I thought (based a previous thread) that we needed to be concerned with VA
output of inverters, not wattage, at least on the transformer based machines
like the SW.
I realize this wouldn't be an actual load if on grid.
In these situations, I just measure DC amps into the inverter to determine the
e the
> magnetic field in the core. This would mean, however, the
> current is 90 degrees out of phase with the voltage, hence
> no real power being consumed.
>
> The majority loss at that point would be the resistive
> loss in the copper, which would be on the order of a few
>
One problem that came up on a project recently, is that your penetrations (as
proposed in your solution below) will essentially ruin the thermal performance
of the SIPs system.
The whole point of the SIPs system is that there are no thermal short circuits
such as framing members that allow heat
It definitely stiffens the pole, and prevents water from rusting it out from
the inside.
While I might use the stiffening effect to get a couple of extra feet out of
the ground, I wouldn't start downsizing your poles because you poured concrete
in them.
I think it would be fair to compare the e
I can confirm that quite a bit of water builds up inside the pipe.
A few times on rewiring old systems, we used self tapping screws to attach
conduit and combiner boxes to the existing pole, and we've had water start
running out the hole when it was close to the ground. This was in a dry climate
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