That's the answer I thought I'd get from most. It's hard to explain the
"days of autonomy" and extended bad weather to people. Most just say, "why
don't you just make a recommendation." That puts me in a spot where I want
to overbuild, which drives up cost.
The other challenge is getting people to
Chris
Yes they seem to be a well-made good quality battery, and we have not had any
problems in properly designed and programed systems.
Kind regards
Tom Duffy
Senior Solar Design Engineer
[Real-logo-X-195]
E-Mail: t...@thesolar.biz
Panama Office: 507-6126-1253
Direct Toll Free: 888-503-6772
In
On these small projects, its very important to nail down the exact load,
to keep the pricing sane. I list on the estimate what the system is
designed to do; for instance 18 w load 24 hrs/ day. Then if something
goes wrong and they are running more than they should you just gently
point out tha
I also see lots of "load creep" Ray"oh, forgot to tell youwe need
to add some all-night LED area lighting to the system. It won't use much
power.."
Dan Fink
On Tue, Jan 21, 2014 at 10:22 AM, Ray Walters wrote:
> On these small projects, its very important to nail down the exact
Bill,
It is good to see that energized conductors are
going to be disconnected near the arrays. I've
been an advocate of disconnecting these
conductors by ground fault sensing equipment
since ground fault detection was first
implemented in the code. If contactors are to be
installed on roo
Exactly. That's why I always have a load profile for each system on
file, and as soon as they're doing something different, we're off the
hook. It opens the door smoothly towards upgrading the system for their
new loads. And yes a new load profile, until they add even more in 5
years.
R.R
+1 on Ray's comment about exact load.
+1 on Ray's recommendation of measuring it yourself.
+2! on Dan's "load creep" comment.
I own a fairly respectable solar trailer, with adequate power and reserves for
many needs. Three years ago, I provided solar power for an "environmental
chili cook-off"
I'm well aware of load creep. After installing a 6kW off-grid system I went
out to a site to diagnose performance issues. The owner had purchased a
six-seat electric golf cart and was charging it off the inverter. I had to
bite my lip to avoid hysterical laughter over this "small" unmentioned load.
I ask the client to ship me all the hardware, camera, routers, modem etc and
set it up and datalog to ascertain precisely how much energy is required, and
if there are any efficiencies to be gain ie DC direct vs Inverter. Many
cameras, at least in the cold north here, also have small heaters in
You can use the systems designed for solar street lights. TIny controllers,
small panels and everyhting mounted on a pole.
On Tue, Jan 21, 2014 at 9:07 AM, Jason Szumlanski wrote:
> That's the answer I thought I'd get from most. It's hard to explain the
> "days of autonomy" and extended bad weat
Drake,
The language in 690.12 is the compromise solution that was reached to ensure
continued industry stability. The alternative to the combiner-level shutdown
was module-level shutdown. It took a consolidated industry effort to push the
module-level requirements out one more Code cycle—for th
Kevin is right on about this too. I just passed on a project, where the
customer insisted they needed a 3 Kw array, but wouldn't share the load
calculations (and they expected a 5 yr warranty!) I knew if we were
having trouble communicating now, it would only get ugly when they were
sitting i
It was suggested to me that since 690.12(5) requires the equipment to be listed
and identified, and there is no standard for rapid shutdown equipment to be
listed to then 90.3 (.4?...oh why isn't the NEC on my iPad...)says 'revert to
the previous version of the NEC' and presto, no need to instal
Hi Brian;
Invoking 90.4 is a decent idea; the only problem is those smarty pants
over at Midnite have been working on their Birdhouse disconnect system
for several years already in anticipation of this requirement. I'm not
up on all of this (still waiting for my copy of the 2014 Handbook) bu
HI Jason,
My only thing to add is the smaller the system the more care I take in design.
And on most of my systems I install a KwH meter. Makes it very easy to see
what they really use a month etc.
Good luck,
jay
peltz power
On Jan 21, 2014, at 11:14 AM, Jason Szumlanski wrote:
> I'm well aw
Brian,
The requirement is generic. A listed contactor can meet the requirement. A
standard is only necessary for products that want to be innovative in meeting
the 30V, 240VA. Killing all power is an option with existing listed equipment.
NEC 90.4 does not apply.
Bill.
From: re-wrenches
OK. So I will have a high rate of acceptance if it buy an Tyco vacuum
relay, and mount it in a Hoffman enclosure, and then put it on my roof?
On 1/21/2014 5:45 PM, Bill Brooks wrote:
Brian,
The requirement is generic. A listed contactor can meet the
requirement. A standard is only necessary
Mark,
If that relay you mention is rated for the dc voltage, current, AIR, and
temperature it will see, you are good to go. The enclosure would have to be
NEMA 4 or mounted in a vertical NEMA 3R box. Then there is always the
question of how much experience do you have with that product in that
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