Thomas Allen Schmidt's posts

Your first question sounds like one for Trace Engineering or Xantrex. As for your second question, I have questions;
How are you getting this reading of 330 watts?
What is the total watt hour day?
Are the modules perpendicular to our Sun at noon time through out the year or are they stationary or on a tracker?
What region of the country are they located in?
Are they in full unshaded sunlight from 8:00 am to 4:00 pm? If not, how many hours of full unshaded sunlight do they have?

Another way of calculating wire size and fuse's and charge controllers is to take the Isc which stands for Impedance short circuited, or the same as amperage short circuited, from the label on back of the PV module. For a 51 watt panel that will probably be around 3.5 for a 12 volt nominal PV module. While you are looking check the voltage on the label as well if its 12 volts nominal the the Vmp or Volts at maximum power (or what I call working voltage) should read some where between 16.5 to 17.5. Whats the brand name?
Getting back to wire size, take that Isc value and add the 156% I mentioned on the previous post.
What that 156% is for, 125% to satisfy the NEC National Electrical Code in addition to 125% to satisfy UL Underwriters Labratories.
125% x 125% = 156%
The reason for this is because they believe that under just the right set of circumstance a PV module will exceed its Isc value. Some of those circumstance are; freezing temperatures while there is a certian kind of cloud that cause a magnifying effect at its edge while there is a short circuit. Very rare, but it could happen and if it does youll want wire big enough to carry those amperages safely.
Getting back the calculations. I will use 3.5 for the example. 3.5 + 156% = 5.46
5.46 x 6 = 32.76
But thats not the end of it calculating this way.
There is derating of the wire for the number of current carrying conductors in a conduit. Also, the wires temperature rating, the ratings of the terminals in the disconect, ambient winter time air temperatures, line loss, etc., etc.. Suffice it to say that after all of that calculating you will still come up with something just under 40 amps as I showed in the previous post.
Go to www.sandia.gov/pv and high light -Publications - then - Codes - and then - John Wiles Code Corner - to learn more about calculating your PV source circuits.  

If this is to be a 12 volt nominal system then start by adding up the wattage of all the PV modules and divide by 12. If its 6 X 51 then you have 306 watts. If you 8 X 51 then that would be 408 watts total.
I chose the lesser of the two, 306 watts for, this example of how I would caculate the system.
So, 306 watts divided 12 volts equals 25.5 amps.
Now the NEC and UL together demand the addition of 156% to that amperage when sizing; wires, fuses, disconects, and charge controllers.
So then, 25.5 plus 156% equals 39.78 amps.
A 40 amp charge controller with nothing smaller than #8 awg THHN copper wire and 40 amp disconnects and 40 amp fuses where needed. You can go through all of the temperature rating and conduit fill calculation if you want to, but I feel that the 156% takes care of all that. One thing you may want to do though is consider line loss from wire length. Chances are in a short wire run that 156% will cover that as well.
Now to size the battery bank.
I like to calculate that based on what the needs are and then size the PV array but since you have the PV array I will start there. We know the PV array will put out 25.5 amps at 12 volts, but for how many hours a day will it do this? I am going to say 3.5 hours. Thats what it is where I live on the shortest day of the year Dec. 21.
3.5 times 25.5 equals 90 amp hours a day.
ok, 90 is 20% of what? That would be 450 amp hours at 12 volts of battery storge. Now you will need too round this up when when you start to look at buying batteries. Site conditions have a lot to do with these calculations as well. Your region as well as weather paterns and avialable unshaded sunlight from 8:00 am to 4:00 pm on the PV array will all have a bearing the autonomy of the system.

13.8 sounds like a voltage while being charged. What you might have to do is size the resistors going by the high voltage limit setting on your charge controller.
13.8 is a good charging voltage. If the battery voltage is this while at rest, not being charged, thats bad. When I say "at rest" I am saying that the battery is not being charged or discharged for at least 1 hour.
The range of voltages that a flooded cell deep cycle 12 nominal battery can go through on a photovoltaic charging system can be
from: 10.6
- this is the point where most 12 volt "gizmos" will not work. Even lights are so dim that they are practically usless.
to: 15.4
- this is an equalizing charge voltage and should only be used for short periods of time. Do not leave 12 volt nominal batteries and charge controller(s) unattended at these voltages.
Without knowing the full specifacations of your particular system there is really no way to narrow this down to a smaller range. One thing is for sure though, there is no one voltage, it will fluctuate.

Typically speaking, a flooded cell lead acid deep cycle 12 volt nominal battery at rest with a full charge will be 12.6 volts.
However, after being fully chagred and equalized, like when they are brand new, it can remain at 12.7 for quite some time.
As I am sure you allready know, battery voltage can go as high as 15.4 volts during an equalizing charge. This would of course depend on the size of the PV array as compared to the battery bank as well as other factors like weather.

I have often wonder what life must have really been like 7,000 years ago. We all know that humans lived on the Earth back then and that they had a higher reasoning. Afterall, that is about the time that written history started.
In fact one could say that, the fact we still inhabit the planet Earth this day is testimony to the fact that we do not need the technologies we have today to survive on this planet.
Dont get me wrong, I am not against these technologies. I dont "see" any arborant evil creatures there. What I do see is humans that have unlocked a myriad of secret powers from this planet but instead of keeping these secrect powers put away for careful study to be sure that they will not become harbingers of death, Humans have unleashed these power with blind abandon. All in the name of profits from commerce.

Imagine that, what and where we are in this seemingly endless universe is in the exact same instant a larger part of something much smaller than us and a smaller part of something much larger. To illustrate - an elderly person feeling tired, having low energy and sleeping more than usual goes to see a healer and after the exam and tests is told by the healer they have a low blood iron count and to take an iron supplement. The person promptly does this. Now shift your focus out towards space, see it there, a meteor nearly 5 miles accross. Hurling through space at thousands of miles per hour towards a planet. A meteor made of solid iron.
Who amoung us really knows of the vastness between microscopy and macroscopy? If you had a choice, would you rather be a natural healthy part of this continuum or a polluted, toxic, and depleted part of this continuum, Inward or outward?
http://www.crystalinks.com/kabala.html
Or we could go about life the way we have always done it. Commerce is to a vast majority of humans today, what making bricks of straw and mud was to Ancient Hebrews.
http://asis.com/~stag/heroes/slaves.html
I dont know that any of this is what you need, but it is something to think about.
God bless you all and Merry Christmas.com  

>I need to know.  Is the
>GPSW 600's "pure sine wave"
>at 60 Hertz and at what
>efficiency? What is the THD?
Item #:GOPGPSW600-12
Alt-E Store doesnt have this info, Go Power's web site doesnt even have it. One way or the other.
So I geuss that puts me in a position where I have to assume that its not 60Hz and look at other brands that do advertise this information.

Here is a place that says their preloaded ready to solder lugs are upto 70% stronger than crimp method.
http://www.quickcable.com/10.html

When I here solder, it brings to my mind the technology used in Square-D heater strips that are used on motor starter overload blocks. If the amperage exceeds the motors rated amps the heater strip gets hot which losens a solder rated for a preset temprature and releases a spring loaded contact which in turn causes the coil to drop out and opens the circuit.

So I geuss we are in agreement that a clean and tight connection is needed when terminating wires. There are several ways availible to accomplish this. So which way is the best? I geuss it all depends on who one trust.

I asked a third party for thier opinion.

Hi, there.  You're right, a poorly made termination will generate a lot
of heat, as well as cut down on system efficiency, when carrying a high
current.  Unfortunately, there's not a lot of agreement on what the
"right" way to make them is.  Jerry Halstead's conversion diary at
http://jerryrig.com/convert/ details how he made his own out of copper
tubing.  Electro automotive (www.electroauto.com) advocates using the
great big (and very expensive) magnalugs and hex crimper, and filling
the magnalugs with noalox before crimping.  However, ther are a lot of
opinions.

On the EV list, Bill Dube' has a reputation for excellent perfoming
racing conversions.  He has advocated making your own crimping die by
splitting a hex socket in two, and using an arbor press to perform the
crimp.

The only thing everyone seems to agree on is that crimping is better
than soldering.  My own experience has borne this out.  When I first
got megavolt, my old electric escort, the connections were original and
some got hot.  A friend of mine who has a motor shop soldered the worst
ones, which helped the conductivity, but it made the cables very stiff
because the solder wicked up the cable.

Several advocate the electro automotive practice of using noalox, an
anti-oxidation compound, but several have actually cut open crimped
joints that were made without adding this stuff years later, to find
absolutely no degradation or corrosion.  A proper crimp actually fuses
the cable and lug into a single mass of metal at the crimp point.  A
good layer of heat shrink between the insulation on the cable and the
lug end seals out any corrosion.  On the other hand, the presence of
the noalox does not hurt anything.  The conductivity is still the same.

People have split open crimped joints made using several methods
(crimper and lug, hammer crimper and lug, split socket and lug, and
hammered copper tubing), to find this exact same thing, so it seems
that a crimped joint, as long as it is crimped well, is the way to go.
They are also mechanically very strong, and if they do get hot, they
still conduct, while solder gets soft and melts.

My own opinion is kind of at odds with EVparts, who I'm representing in
this FAQ, since I get my wiring supplies elsewhere.  I use real cast
copper lugs and a hammer crimper (it works best if you set it on
concrete), and put a small amount of noalox in the lugs before crimping
(after all, it doesn't hurt).  If there is too much, it splatters all
over everything when you crimp it.  I buy the "extra heavy duty"
electrolytic copper lugs from www.waytekwire.com.  They are the same as
magnalugs, just a different brand.  they are thick enough to
effectively carry high amperages and to effectively crimp to large gage
cable.

Since the hammer crimper deforms the lug a bit differently than a real
hex crimper, I try to do two locations along the length.  It has worked
well for me so far.  Both when I rebuilt megavolt, and on this go-kart
I'm doing now.

You may also check out Ken Norwick's conversion diary at
http://advanceguard.dhs.org/conversion/ConversionStart.htm to see how
he did his connections.

One other note, I found surplus heavy gage cable assemblies (4/0 gage)
with silicon based insulation and lugs already assembled at a surplus
place, and I used those as the motor cables on megavolt, since motor
current can be higher than battery current.  I think I got them at
www.surplussales.com, but I'm not sure.

Hope I haven't muddied the waters too much.  Basically, most have had
good experiences with crimped joints, made with a variety of methods.
It is necessary to ensure the crimp is well done, though.
 

I am going to assume that you do not have the generator as yet.
Go to the Alt-E Store and look at the Xantrex SW5548 inverter. Read the specifacations. You will see that it is built with relays that allow the user to chose either grid (or genset) or battery power just by flipping a breaker off or on. The user would have to size a battery bank as well.
An example-
Choose certain 120 vac circuits such as lighting and general receptacles. Move those circuits to a separate smaller breaker panel. Determine the total watts ( the SW5548 is good upto 5500 watts continuous) and the watt hours they would consume in a 24 hour period. Feed the inverter from the main or sub panel. Grid power will pass through under normal circumstances to the dedicated circuits and maintain a charge on the battery bank. In a black out or if you turn the breaker off that supplies grid power to the inverter, the inverter will power those circuits from battery power. Then as time and or money allow, add PV modules or wind genny's or micro hydro or whatever to charge the batteries instead of grid power. The cost difference between this system and the one you speak of will be relatively the same when you consider the fuel and maintainace required on the genset over over a lifetime. Off grid living is most cost effective for those who want live so far from the grid that it would be less expensive to buy all of the RE equipment than to buy a line extension. Or you could do it just to be able to brag to your friends that you dont have an electric bill every month;}  

I stand corrected. Oso is correct, I was refering to a full compression lug and die.
If I may defend myself?
At work "crimp" has become a slang of sorts for us. Its easier to say than "full compression lug and die." The other guys I work with would know this considering the type of work we were doing at the time it was said. This slang just "spilled over" into my writing. I will try to be more precise and use less slang in future postings.
Also where one might think I was refering only to the THHN wire going to the motors. the motor leads are fine stranded wire cables and to date I have yet to see any soldered. I wish they were because they are always all spread apart and I have to spend time "smoothing" them out so that they will go into the lug. We use full compression lugs and die on those as well. Using lugs with single hole tangs on each, and then bolting them together in thier appropreate groups with the THHN at the "cathead." Then each splice is wrap in; VC tape, rubber tape, and then finished off with super 88.
I should have been more clear as well about not using solder only as a means to bond the wire to the lug. If the lug gets hot for any reason, hot enough to losen the solder. This will cause the bond to get loser and hotter and loser and in time, fail. This is why I suggested using a full compression lug and die along with the soldered wire ends.
Here are some web sites with links that might be of interest to you. Although some of them deal with harsh conditions that a stationary RE system will never see, the techniques used should insure a very reliable stationary RE system for years to come.
http://ebusiness.ilsco.com/webapp/wcs/stores/servlet/CategoryDisplay?storeId=10001&langId=-1&catalogId=1&categoryId=106
http://www.evparts.com/firstpage.php
http://www.nedra.com/
http://www.keison.co.uk/furse/compression_tools.htm

http://www.autoshop101.com/forms/h5.pdf
Skip right to page 5 of this file and you can read what they have to say.
One of my duties as an electrician were I work is to "wire up" large 3 phase motors. Working with large wires from 2/0 upto 500 MCM we use a hydraulic crimp tool on tinned copper lugs.
Maybe its just me, but I would be leary of a solder connection at the high amperages 2/0 wire might carry. I can see a benefit to soldering the ends of fine stranded wires, but I would still use a hydraulic crimping tool on that 2/0. Some times electrical supply house's have these tools that they loan out to there contractor patrons, but if you could carry your work to them, they may let you use it there.
I thought I was being smart by purcahsing one of those crimping tools that you smack with a hammer when I made my own battery cables but, not so smart. Out of 24 connections three came lose and began too heat up after a couple of years. I just as soon not have any lose connection, you know what I mean?
Since your going all the way, with soldering and all you may want use a megger and dry out the wire in that cable before it gets sealed up for ever.  

LAST EDITED ON Dec-22-04 AT 05:30 AM (EST)

I need to know.
Is the GPSW 600's "pure sine wave" at 60 Hertz and at what efficiency? What is the THD?
Item #:GOPGPSW600-12

How is that new free system doing? Can you see a big difference in your monthly electric bill?
I checked with, what would be my local utility power company about them paying me the equivilent of one months bill each year, "we don't do that". He actually had more to say but at that point all I heard was "blah blah blah, blah blah, blah blah. Go figure.

LAST EDITED ON Dec-12-04 AT 04:26 AM (EST)

I should also add the fact that watts are watts. Watts dont know the difference form vac to vdc when doing these calculations. Also, most any electrical gizmo will have a tag on it stating either watts or amps and volts or sum combination thereof. Again learn the fundementals of Ohm's law. Its all in the math, and in the pocketbook.

LAST EDITED ON Dec-12-04 AT 04:24 AM (EST)

To make a long story short, one can do with PV power what one can do with utility power. Its a matter of sizing the PV system to fulfill ones electrical needs. Study Ohm's law, calculate your electrical needs into watthours, determine amphours of battery storage from watthours, size the battery bank to stay within the top 20% of fully charged, and then size the PV array to replace that amount of amphours in at least one sunny day.
Example: Lets say you want to burn an 80 watt load 24 hours a day all year long.
24 x 80 = 1,920 watthours
then divde this by a nominal battery voltage,
1,920 / 48 = 40 amp hours
then to stay in the top 20%,
220 x 20% = 44
a battery bank of at least 220 amphours @ 48volts,
Now to replace that 44 amphours in one sunny day,
1,920 / 4 = 480
in this example 4 is the number of hours of equivilent full rated charge from a PV module. This will vary from; region to region, season to season, how the PV array is mounted and, the weather. 480 watts @ 48 volts is the size of the array, this however is absolute minimum. It may be nescessary to increase the size of the PV array and the battery bank by as much as 50% or more for total autonomy. That all depends on site conditions.

Opinions are like belly buttons, everybody has one. This is mine (opinion that is).
With a properly sized system including; PV modules, battery bank, and true sinewave inverter(s) and, possibly other RE sources one would not have to give up any creature comforts. One my have to look for alternatives but you already know this.
(There is a stigma that goes with looking for an alternative and that is, that we are settling for second best. If you havent already, which I feel you have, try to overcome this.)
An all electric home could be totally solar powered off grid but cost effectiveness becomes an issue.
The cost of the system could be higher than the cost of the home itself. High amperage, 240 vac loads such as electric ranges, central hvac, clothes dryers, and water heaters do not lend themselves well to off grid solar applications for this reason.
To be concluded.

LAST EDITED ON Nov-28-04 AT 03:28 PM (EST)

I didnt care too much for that price ethier.
Especially when its all "homegrown" technology.
If anyone wants to see how their generators are built, for free, visit.
http://www.otherpower.com/otherpower_experiments.html

Your electric utilities service provider will need to know if you are going to synchronize a generator with theirs and connect your generator with their grid. This is a must. You could facing big legal issue's if you don't. The nations power grid falls under the jurisdiction of national security.
http://www.basler.com/html/rscrel.htm

http://www.cbo.gov/showdoc.cfm?index=4552&sequence=5
More "food" for thought on this subject.

I am sure there are such devices. Have you considered the cost effectiveness of such a system. I may be wrong but it would seem pretty darn hard to beat the utilities price per KWH with an infernal combustion engine.
It would be great if the human race could relearn how to live without electricity again. Or, at least unlearn how electricity is produced and sold to the masses. Instead to be energy self reliant. Oh well. I can dream cant I?

Please accept my apologies Avocado. I tend to be a bit cavalier if not zealious when it comes to peoples misconception of electricity. Its not there fault. Its all been accomplished by generations of misdirection. Kind of like how a magician use's misdirection to move the viewers attention away from one hand with the other hand while the first hand is preparing the trick.
The need for utilitized electricity is an illusion. What has happen to the human race is this; we have been gradually pursuaded through generation after generation to become more and more dependent on comerce and less on self reliance. I cant say it enough, mankind survived for well over 7,000 years without all of the technologies we are paying for (in more ways than one) today.

http://www.otherpower.com/otherpower_experiments.html

Take caution with those Intermatic timer controllers. The timer itself may be dc powered but the load contactors may not be dc rated. Direct current has a dendency to either; weld, or transfer the metals from one side to the other, or corode contacts that are not rated for direct currents. Read the specs. carefully.

Start by thinking of what you want to do with that power first. Then figure how much power you will need. Turn it into watthours. Then determine how many hours of equivilent full rated power you can get from the Sun in your region. Example-
Lets say you want to power 3- 100 watt bulbs for 6 hours. This would be 1800 watthours.
Now lets say that in your region on the shortest day (dec. 21) a PV module will recieve 3 hours of equivilent full rated power.
Now we divide 1800 by 3 and we get 600. That would be a 600 watt PV array in full unshaded sunshine from at least 9:00 am to 3:00 pm and perpendicular to the Sun at noon time on the shortest day.
None of this takes into account the battery storge or inverters to make 120 vac from the low voltage dc that the PV modules.
One of the best investments I feel that I made when we decided to go solar was a subscription to HomePower magazine. The reader gets to see various systems installed as well as rendered schematics and he or she becomes familar with phrases and terminologies and what they mean by reading the articles and reports and all.  

Only those charge controllers made for that task such as the OutBack MX60 and other MPPT (Multiple Point Power Tracking) charge controllers. Voltage converters actually "burn off" higher voltage to mkae a lower voltage.

LAST EDITED ON Nov-25-04 AT 10:26 AM (EST)

LAST EDITED ON Nov-25-04 AT 10:26 AM (EST)

What would happen is the PV cell temperature would get hotter causing the output voltage to drop and if left this way ruin the module.
A better approach would be to find a way to super cool the cell which would drive its voltage up without harming the module.
Wattsun has created a PV concentrator module that use's; Freznell lense's, speacial PV cells the size of a dime, and large heat sinks. The whole thing has to track the Sun very closely though.
http://www.wattsun.com
I was wrong. Wattsun created the tracking system for the concentrator PV array. It was actually Midway Labs Inc. that produced the Array but try as I did I could  not find a web site. Instead I did find this one.
http://www.entechsolar.com/

Not that I am aware of. Most of the electricity in the USA is produced by the burning of coal.
It would be safe to assume that any type of non-polluting renewable energy would be more cost effective overall than burning a polluting non- renewable energy such as fossil fuels.

In one years time the United States of America imports more than 3 billion barrels of crude oil.
We are paying anywhere from $35.00 to $50.00 per barrel. This is equal to 105 to 150 billion dollars. Since the year 2000 that would be
somewhere between 420 to 600 billion dollars.
$600,000,000,000.00
If this where seconds, how many years would that be?
If it where drops of water, how many gallons?
Anyway, just think about it.
http://www.apolloalliance.org/

LAST EDITED ON Nov-07-04 AT 05:17 PM (EST)

I am curious, is your hot water heater fuel oil fired as well?
I would agree with TOM6000.
Solar hot air heaters mounted on the roof can take some big flex duct, not to mention if the ducts are long it could be inefficient, like breathing through a long straw would be for us people. If there is not a closet nearby with room to spare for the supply and return ducts then it might be nescessary to run the smaller water pipes from a solar hot water heater to an air handler that use's hot water from the potable hot water heater instead. Maybe even add a second tank for increased storage.
This is why I asked about your existing hot water heater. If it is fuel oil fired as well then you could just do away with the fuel oil air heater, put an air handler in its place that use's hot water from the existing potable water heater and use the solar hot water heater as supplemental hot water.
A closed loop solar water heater system would preheat a storage tank that would in turn feed the potable water heater reducing the amount of fuel oil it use's. There are lots of options and varibles such as the age and or efficency of the two existing systems. Is it time to replace any of this equipment anyway? (I know you wrote that it is a new home but I dont know if that is brand new or new to you folks.) As you allready know, oil prices aren't going down.
Have you looked at www.kingsolar.com or talked to any local HVAC contractors with expierence in solar energy?
Let us know what you decide. One of the things I would like to see more of in this forum is what folks decide on and descriptions of there systems. Problems they may of had in the installtion, how much money it has saved them, etc. etc.. Best of luck to you all.
http://www.toolbase.org/tertiaryT.asp?DocumentID=2084&CategoryID=945