Wisconsin Farmhouse Remodel

Started by Windpower, September 14, 2012, 09:00:52 AM

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MountainDon

My EDR program gives me the following:
For 48 VDC, 150 amps, 3/0 copper wire, 90 foot one way distance = voltage drop of 4.31%.
Less than the 5% the power company uses as a cut off but more than the 3% that is regarded by many as best for alternative power systems.

Other data:
90 feet wire, one way distance, 48 VDC, 125 amps = 3.59% voltage drop
90 feet wire, one way distance, 48 VDC, 100 amps = 2.87% voltage drop

90 feet wire, one way distance, 48 VDC. 105 amps = 3% voltage drop.

But the wire won't be transmitting 150 amps all the time. Anytime there is less than 100 amps you would be under 3%.

That said, I have a question...   

Why place the charge controllers out by the modules? If you ran higher voltage through the wires and had the charge controllers by the batteries it would seem that would lower the percentage voltage drop. Of course the maximum cold weather voltage would have to be within (less than) the maximum voltage rating of the controllers.

In any event the Vmp of the modules should be at least 60 VDC in order to take advantage of MPPT... the controllers will be MPPT won't they? So, if the module voltage is 60 - 72 VDC that will lower the voltage drop too.

Good luck with the MRI!
Just because something has been done and has not failed, doesn't mean it is good design.

Windpower


Thanks for the input Don

According to the Xantrex string sizing tool each of the 4 strings of panels would need their own contoller (Xantrex MPPT 60 - 150  60 amp maximum at 150 V max). I thought the output from each of the contollers (7500 total panel watts / 50 V = max 150 Amp on a cold sunny day) would then be bussed together to feed the batteries through the 3/0 wire run to minimize wire cost and simplify the set up

The alternate would be four runs of wire (one from each string of panels to the contollers near the batteries ) -- this would be another major wire purchase that I was trying to avoid --- although I could reduce the wire size for the approximate 40 A for each string it was still more money for wire (4 runs of #2 would do it)

ebay for 750 feet of 2 conductor 2 gauge ( albeit more than I need )


http://www.ebay.com/itm/750-2-2-Gauge-AWG-Type-W-Round-Portable-Cord-Super-Cable-Wire-Flexible-RHH-RHW-/150859407345?pt=LH_DefaultDomain_0&hash=item231febdff1

$3765  ouch !

about twice the 3/0 wire

I am starting to think there is no one best answer to what should be a simple problem but that rapidly gets to be rather complex

Often, our ignorance is not as great as our reluctance to act on what we know.


MountainDon

Quote from: Windpower on October 07, 2012, 04:49:31 AM
I am starting to think there is no one best answer to what should be a simple problem but that rapidly gets to be rather complex

Right on that   Many ways to skin the proverbial cat! No matter what or how lots of power requires lots of wire and as the distances grow it is more complex.

Not to make the problems more complex, but did you look at Midnight Solar's charge controllers? They have models that go as high as 250 volts.
Just because something has been done and has not failed, doesn't mean it is good design.

Windpower


I think I will try to  stay with Xantrex so the parts can talk to each other over their Xanbus network

Xantrex just came out with a 600 volt model but at 80 Amps and $1000 makes it hard to justify verses the $400 XW60 - 150

Although the latest Evergreen panels I got  from Sunelec are rated to 1000 VDC system voltage (my first 12 panels are 160 V max IIRC), I have some concerns about safety at 600 VDC (600 VDC can be quite lethal)  -- I would have to fence and/or lock up things very securely from tiny curious 6 year old fingers since the first stage will be ground level mounts as opposed to out of reach  roof or pole mounts

Hard to plan for the future when the products are a fairly fast moving target, I guess

maybe for the next setup in 10 or 15 years 
Often, our ignorance is not as great as our reluctance to act on what we know.

ColchesterCabin

Ok, I was just catching up on this tread and I want to pass along a little bit of irony.

Windpower talking about solar panel instalations...

Just saying that was too easy not to pass up. Besides that the foundation looks great!
Visit my thread would love to have your input http://countryplans.com/smf/index.php?topic=12139.0
Feel free to visit my Photobuckect album of all pictures related to this build http://s1156.photobucket.com/albums/p566/ColchesterCabin/


MountainDon

It does make sense in many ways to stick to the same brand of equipment within a system.  :)

Re DC voltages. While I doubt anyone will argue that high voltages like 440 and 600 can easily be lethal not everyone may realize that 48 volts is also getting into the lethal range. OHSA, NFPA and other organizations consider 50 volts as the threshold where certain safety regulations take effect. And as you know when talking about a 48 volt DC system, the voltages are frequently going to be higher. So the 48 volt system should be treated with the same rules and respect as those very high numbers.  Lockable enclosures will be your friend for life. 
Just because something has been done and has not failed, doesn't mean it is good design.

Windpower

Good one, Colchester

The wind turbines are late next year or spring '14 hopefully.

I am working on a time frame for getting the 'bones' down first

depending on when I retire so I can work full time on this (speaking of irony  ;D

it looks like this is a 2 year project into phase one (House done, garden started, solar operational, tear down old garage (the shed roofed gray building behind the back hoe in the last posted pic) and get the shops functional -- not necessarily in that order. Oh, and somewhere in there we have to sell/rent our house and move.....

I think the shops are a top priority after the house is done and then the solar. I may work on the shops during the garage/house construction. There is one off the side of the barn (needs work) and the new one in the new garage when it gets done (hopefully before the snow flies this year. Eventually it would be nice to build a 40 X 40 'dream shop' in half of the pole building with concrete floor and heat (it would be so good to have a warm shop next winter)  There is a functional (I think) wood stove in the basement that was used to heat the house by the last tenant -- should work for the 40 X 40 shop I think

more later ......

Often, our ignorance is not as great as our reluctance to act on what we know.

Windpower


Good points, Don

I work on lab instruments -- most are 220 in from the mains (as the UK reps call them)

inside voltages run up to about 10 to 20 KV for certain circuits

one instrument has a 550 VDC power supply and although well protected, we sometimes have to read it with a  meter when troubleshooting, as the EE that designed it said in training

"Well you have to be careful, it will knock you on your ass"

Another precaution around batteries is to insulate wrenches that are long enough to span pos to neg leaving only the working end bare metal and also not wear any jewelry or rings

I have not worn a ring working on instruments for 25 years and rarely a watch
Often, our ignorance is not as great as our reluctance to act on what we know.

UK4X4

I'm an instrument engineer

The only things i've ever worked on at 10-20kv although battery supplied equipment were gieger counters !

I did my aprenticeship at an atomic research center in the UK - the site is now mostly moth balled and rented to tech companies

we had over 50 active reactors when i was there- from submarine fuel cells to full reactors supplying the grid

and the favorite machine----the worlds biggest air gun !

used to test reactor wall structures- and various others things during lunch !


Windpower



Sounds like a fun toy, UK

I shorted  5 KV once due to a bad ground --- quite a wake up -- fortunately low current -- uA


not interested in 600 VDC from panels for me or other visitors -- you only have to forget once



Often, our ignorance is not as great as our reluctance to act on what we know.

Windpower


Finally finished the front elevation -- lots of time here lately waiting for the knee to work better

MRI showed a torn ACL hopefully the PT will get me operational without surgery




A picture of the house before.  The window in the center of this pic is the window drawn to the left of the  front door in the front elevation, the front door is about where the window on the right is now 

Often, our ignorance is not as great as our reluctance to act on what we know.

Sassy

Your place is going to look really great, Windpower! 
http://glennkathystroglodytecabin.blogspot.com/

You will know the truth & the truth will set you free

Windpower


Thank you very much, Sassy

We are going up tomorrow to meet with the carpenters on the materials list and spec out the doors and garage door

weather permitting the floor for the garage will get poured

It is now a race with the weather but the carpenter says he should have the garage framed and dried-in in a week or so after they start about Nov 1

Apparently they are known for rapid builds -- he has one house to frame in before ours and 'well somewhere in the next few weeks we have a pole barn to put up too but that is only 2 or 3 days'

November is an unpredictable month up there --- It could be very nice in the 50's, I remember one deer season (thanksgiving week) that was so warm we had to ice the deer after field dressing them or one year it snowed 4 inches in the second week and stayed till April -- *fingers crossed*

on a side note we got delivery of the 3/0 wire for the panels -- all 300 pounds of it --- fortunately I had a heavy duty 4 wheel dolly my wife used to push it down the driveway while I hobbled along behind



Often, our ignorance is not as great as our reluctance to act on what we know.

Sassy

Meant to mention your knee - hopefully you'll get by without surgery - I've had a tear in my right knee for a couple years - caught my foot on some strapping tape that had been buried up by the shop & fell onto a pile of plywood - hit my knee pretty hard  >:(  My next surgery will be getting my right hip replaced - I've put it off as long as I can...  not looking forward to that.
http://glennkathystroglodytecabin.blogspot.com/

You will know the truth & the truth will set you free


Windpower

Hang in there, Sassy

it is amazing how your life can change in split seconds

*hug*

wife and I are going up there tomorrow -- there is so much to do yet



Often, our ignorance is not as great as our reluctance to act on what we know.

Windpower



Update

we didn't go up last week because the weather was rainy and they didn't plan to pour

So I just checked the weather for next week and -- rain rain rain.

Wunderground weather predicts rain for the next 10 days with some snow in there too   

So I was getting concerned because the there are 2 support pads needed for the second floor supports in the floor -- no floor -- no garage

I called the concrete guy today asking him what the plan was

To my relief he said -- "We poured it yesterday"  (Saturday) He even cut off the old cellar door and refitted it (I was going to do that )

Then he said he was going out to score it today (Sunday) 

I feel that we really picked an extraordinary contractor

What a relief !




What a relief !!


Often, our ignorance is not as great as our reluctance to act on what we know.

Redoverfarm

Yes it sounds like you got an exception to most that are in buisness.   :)

Windpower



We are very pleased, Red

We picked him from Angie's list -- I think he has earned some very good ratings from us

Often, our ignorance is not as great as our reluctance to act on what we know.

Windpower

The floor looks great -- Meyers did a great job -- very smooth

Nice !


Notice all the leaves are down now -- the next race is to get the garage dried in before the snow which could come any time

Windows should be there next week ...





Often, our ignorance is not as great as our reluctance to act on what we know.

Windpower


Got the shipment of twenty  235 watt solar panels from Sun Electric



unfortunately one was damaged --- called sunelec and they said they would take care of it

Often, our ignorance is not as great as our reluctance to act on what we know.


Windpower

Went up Sunday to get generator power to the house so we can run the well pump

Heavy rain and 60 degrees turned the place into a mud pit -- made getting anything done more difficult

Monday morning 21 degrees and windy  --  10 degree wind chill -- but at least the ground was frozen making walking easier,  oh and snow too





but by early afternoon -- power to the people  house

The reliable (so far *fingers crossed*)  China diesel lives and is very quiet --(not "Silent" as claimed in the bottom right corner blue decal) just a low barely audible hum inside the house. The well pump powers up just fine from it, too




and is hooked into the house

Often, our ignorance is not as great as our reluctance to act on what we know.

Windpower


Went up for deer season friday and there was a stack of material waiting

28 TJI's and 3   38 foot long beams









10 minutes after season open my nephew bagged one of the local bucks




me --- still have my tag   





Often, our ignorance is not as great as our reluctance to act on what we know.

Windpower



We went up over the weekend --- I still have my deer tags  :-[

The concrete is poured in the crawl space and the trusses are to be delivered Wednesday

The carpenters are starting tomorrow.

exciting times .....

I'll post pics later this week
Often, our ignorance is not as great as our reluctance to act on what we know.

Windpower


Drove up and back yesterday -- quite nice day for late November 43 degrees and sunny

A deer stopped by to check it out here's a print next to my size 10 boot



a pic of our 'front steps' for the week end with power hook up -- crude but functional



here's what they have done in the last two days

no more 'front steps'







This will be the door to the house from the garage






They got the garage door wall up before they left for the day



next we have to get the tub for the apartment upstairs before they frame in the stairs -- glad the carpenter reminded me

trusses for the roof should get there today
Often, our ignorance is not as great as our reluctance to act on what we know.

Windpower

More progress on the garage





Stairs are in



Looking out the south west window (the one over the single garage door)



Gray day at Bricolage Farm




The trusses arrived Friday but they decided not put them up due high winds forecast for the weekend





hopefully the weather will cooperate tomorrow and they can set the trusses

With the cold coming in rapidly we/they decided not to shingle the roof since it won't get hot enough to seal them down and we run the risk of them blowing off (we are on a windy ridge top and Mike said it wasn't much fun replacing shingles on an icy 12/12 roof ) instead we are going to put down ice and water shield until next spring.

Often, our ignorance is not as great as our reluctance to act on what we know.