Tech Question...

[ygmir]

hahaa, yeah, this is the point, it all sounds like the teacher on a Charlie Brown cartoon (how old am I? haha).

I've just not spent enough time with electronics, to get all this.
and, at 10K for the solar system, am really not wanting the "square smoke ring" thing......

Good info here, so much to digest, let alone comprehend.

[Lassen Forge]

Ma Fwa, Fwa fwa mwa mwa mwa... Fwa mwa mwa fwa mwa...

I think... THINK... the only component you would damage would be the cheapy 300W inverter. It all depends how much "backflow" current it can handle. It may be a non-issue, but the risk would be in feeding the 3KW INTO the inverter, not the other way - after all, the system is designed to be live on the grid...

If the inverter could handle it (and off the top of my head I can't see why it wouldn't, really) then you'll be kinda home free.

Remember - the system is looking for 110V at 60 HZ to detect to sync the Freq. of the system... you could almost, I'm guessing, segregate it through a transformer or something. Damn, it's been too long...

You could do a smoke test - - make a double-plugged cord, plug one end into the wall, the other into the inverter, see what happens. At best, nothing, at worst, you fry the inverter and/or pop the breaker but then you know. And inverters like I'm talking about are relatively cheap - say $30-ish... beats $10K.

[ygmir]

hhhm,m\
\\

good idea..........I even have a 400w inverter from my MV..........

thanks, BBS..........

[kman]

Plasma kicks ass on flour and LED;
http://news.cnet.com/Luxims-tiny-but-po ... 34653.html

The one question begging an answer would be, "What is the life expectancy of this plasma lightbulb?" That is why plasma TV's went by the wayside. Even though they offered better images their 10k hour life span made them impractical.

FWIW, you're using outdated information, or a typo. Modern plasma TV's have a half-life rating of approx 100,000 hours. That's over 50 years given common usage patterns of 3 hours per day. Even if you run it 6 hours per day, I'm pretty comfortable with a 25 year life-span of a device I will probably replace in no less than 10 years.

[gyre]

Reducing brightness typically increases life and sharpness, as with crts.

[Trishntek]

Plasma kicks ass on flour and LED;
http://news.cnet.com/Luxims-tiny-but-po ... 34653.html

The one question begging an answer would be, "What is the life expectancy of this plasma lightbulb?" That is why plasma TV's went by the wayside. Even though they offered better images their 10k hour life span made them impractical.

FWIW, you're using outdated information, or a typo. Modern plasma TV's have a half-life rating of approx 100,000 hours. That's over 50 years given common usage patterns of 3 hours per day. Even if you run it 6 hours per day, I'm pretty comfortable with a 25 year life-span of a device I will probably replace in no less than 10 years.

I did not know that! I have seen some high dollar medical imaging plasma screens fade away within three years. But they are used nearly 24/7.

[Trishntek]

In my search for batteries, it seems the 6V/395Ah battery has the most bang for the bucks found so far:

http://store.solar-electric.com/cr395amdecyb.html

121 pounds each is pushing the limits for portability. But two of those would sufficiently run a 750W system. One of them would be enough for Burning Man! $1200 for four of them is the best price per watt I've found so far.

[unjonharley]

We have a state surplus barn here in Salem.. They dump new batteries like that for half$..

[unjonharley]

What is the radius of 200 feet of wire in a circle?

Dumb down to me OK?

[gyre]

Diameter is 63.66197723.

Half is the radius.

http://wiki.answers.com/Q/How_do_you_fi ... cumference

[Trishntek]

it's all how you slice the pi

[Elorrum]

What is the radius of 200 feet of wire in a circle?

Dumb down to me OK?

circumference is pi D.

D = 2 x radius

200 = 3.14 D

D= 200 / 3.14

D= 63.69

r = 31.84

[Trishntek]

So I go to LOWES for a grounding rod. Call me stupid,,,,,, EIGHT FEET? Really? I don't wanna poke a hole in my sewer or something like that and I always thought 3-5 feet was sufficient. Is it relative to the diameter of the rod used? There are several websites willing to sell you the seemingly "proprietary" code book of the NEC. Anybody know? I'll keep lookin',,,

[Trishntek]

Okay, I found it,,,, sheeesh,,,,,

http://www.transorbelectrical.com/pq/te ... dRodR8.pdf

Stupid

[ygmir]

So I go to LOWES for a grounding rod. Call me stupid,,,,,, EIGHT FEET? Really? I don't wanna poke a hole in my sewer or something like that and I always thought 3-5 feet was sufficient. Is it relative to the diameter of the rod used? There are several websites willing to sell you the seemingly "proprietary" code book of the NEC. Anybody know? I'll keep lookin',,,

I think you can put said ground rod in horizontally.
IIRC, it needs about 18" of cover, well tamped soil. the deeper the better, though.
But, it's my memory, so......

[Kinetik V]

8 foot long, straight down, clamped properly. No shortcuts, no compromise, a good solid ground is absolutely CRITICAL and will serve you well for years to come.

Yes driving that rod is going to be a pain in the rear. But this is one thing you just gotta do.

[Elderberry]

So speaking of grounding rods, does anyone use them with their generators at BM?

JK

[JStep]

So what happened with Y2K?

Lots of IT people had to go to work at midnight on NYE to watch nothing happen, thus ruining their quasi-millennial NYE celebrations.

[motskyroonmatick]

8 foot long, straight down, clamped properly. No shortcuts, no compromise, a good solid ground is absolutely CRITICAL and will serve you well for years to come.

Yes driving that rod is going to be a pain in the rear. But this is one thing you just gotta do.

If this is going to be inspected one thing I have had an inspector look for is mushrooming of the top of the ground rod to make sure it is full length and has been pounded in. It is advisable to put the ground clamp on before pounding so that you don't have to battle the mushroomed top of the ground rod to get it on.

I have had very good luck pounding ground rods in to hard ground by adding water to the ground as you pound the rod down. It seems to follow the rod down and lubricate the soil making it easier for the rod to go through the soil and not bind up on the way down.

One can generally assume the relative location of the sewer line leaving the house by looking at the plumbing under the house. Generally it is off of one of the bathrooms. Usually the septic tank is off set from the house a fair distance.

You might call for locates if you are uncertain of where your power, phone or cable enter the house. If any of that comes in underground it would be wise to do so. Just tell them you are getting preconstruction locates for planning purposes. This can lead to trouble if you are doing non permitted construction as the city will come out to locate water, sewer and storm if you are in an area with those services. It seems to me that you are not in one of those areas if my memory serves me correctly.

Can you take a picture of the location so we can have a look at it? 1000 words and all...

[motskyroonmatick]

FYI I have excavated a galvanized steel ground rod before and found the entire core to be oxidized. If this is a long term thing it may be better to go with the copper ground rod. I believe there is also a material that can be mixed up and mixed in with the soil if you are burying the ground rod in a trench. It is some times used in arid areas to provide better grounding to the soil. I have no idea what it is specifically though.

[Trishntek]

So what if I simply clamp to an outdoor faucet pipe? This unit is portable and not necessarily a permanent power plant. I built it primarily for BM, but might as well use it here and keep it exercised. I'll take some pictures and post them soon.

[motskyroonmatick]

I've lived in several houses where the panel was grounded to the metal water supply line to the house. It was a very common practice.

I think it would be ok to ground to the faucet just as long as you know for sure that there is continuous metal pipe for quite a ways under ground.

If it were my place I would do the ground rod thing just to be sure.

I'm curious to see your power plant and will be reserving more comments until seeing it.

[Trishntek]

Hopefully this url works.

http://www.facebook.com/album.php?aid=4 ... 0031825783

If the pics cannot be accessed, let me know and I will find another way.

[Trishntek]

Let's try this:


A small BBQ cover works perfectly! I grommeted the holes through which the upper bracket attaches to the tool cart's top rail.

Four 6 volt golf cart batteries in series rest on the bottom shelf. Note the grounding clamp above the wheel.

This bracket is designed to slide and pivot for sun angle adjustment.


The inverter is too thick to fit in the drawer, but the top shelf is covered anyway. I could have gotten away with a single negative terminal, but this provides a way to disconnect each component independently.

The controller has built in safety controls and the inverter has built-in GFI. This particular brand of inverter is the only one I've seen with a full TWO year warranty.

[Trishntek]

Yup, got over zealous on the grounding. Those terminals must be isolated from one another via the cart chassis. I removed those interconnecting ground cables and everything is tickadeeboo.

[motskyroonmatick]

I take it tickadeeboo means it is working great.

Ok you are leagues ahead of me with solar. Carry on!

I really like that set up and could definitely put that to use. Cool.