OFF GRID POWER; various thoughts on...

Started by MountainDon, January 13, 2009, 02:18:39 AM

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MountainDon

#1100
Well, to my mind the Morningstar doesn't offer much other than convenience for simple readings. We have an Outback Mate mainly as it is required to program the Outback Inverter. It also supplies interesting info; voltages, amps in, kWh in (CC to batteries), system high/low voltage, and so on . That info is in a 128 day log so is useful to review. Aside from programming the main thing I use it for is to check that the system goes into float mode every day. If it does not float daily, there must be a good reason like greater use or cloudy weather. That's basically all I worry about day to day.  I've proven that our typical pattern of use is covered amply by the capacity of the batteries and the PV modules.

The Bogart meters are interesting and I have been tempted several times to buy one. I had originally thought I would get one but delayed the purchase, although I did include the low voltage wiring into the build just in case I wanted one. But I don't need to know the state of charge on a daily basis. If it's cloudy for several days I may use the hydrometer. Or I may just run the generator because it hasn't been run in a while.

I suppose if one is running their batteries "way down" on a regular basis one of the Bogarts could be a useful "how much is left" tool. But if that is the case perhaps the money would be better spent to go towards improving capacity?

YMMV.  my 2 cents....
Just because something has been done and has not failed, doesn't mean it is good design.

OlJarhead

Hmm...good points all.

So far it appears I'm not pushing my system at all so I suppose I don't NEED one....but I'm an information glutton! 

However, at $225 from the source i normally buy from I'm not so sure I need the info THAT much! ;)


OlJarhead

Speaking of system usage etc, I got a good test this past weekend:  The panels somehow tripped the breaker (only second time this has occurred) and I hadn't noticed for a day or more!  Then I noticed, when showing off the system, that it wasn't charging in the full sun and was showing the charge between 80 and 90%.  I checked everything over and saw the panels were kicked off so reset the breaker and everything went back to normal.  I then checked the system and saw more then 24 hours without charge! lol

So there I was, using the system and not charging for at least 24 hours and still running about 85 to 90% of charge!

Gotta love that!

considerations

Trimetric Meter

http://www.bogartengineering.com/

No pros and cons....not hooked up yet...pulled the wires but did not identify which end in the power shed is the same end in the house...not sure how to be sure I hook it up the right way.  The instructions warn of catastrophe if it gets hooked up backwards.  growl

MountainDon

What's the length of wire run? Have you enough of any kind of wire, pipe, etc. to run a temporary line (through a window or whatever) to use with an ohm-meter, trying the other leads one by one?
Just because something has been done and has not failed, doesn't mean it is good design.


Rob_O

Quote from: considerations on March 28, 2013, 08:29:20 PM

pulled the wires but did not identify which end in the power shed is the same end in the house...not sure how to be sure I hook it up the right way.  The instructions warn of catastrophe if it gets hooked up backwards.  growl

Use a voltmeter, if it reads (-) voltage switch the wires
"Hey Y'all, watch this..."

considerations

Whoops, didn't mean to pull the conversation off track with my stupidity.  It just put me "off" when I realized what I had [not] done.  I have since acquired a volt meter...and will read those instructions as well.  d* 

OlJarhead

http://www.aimscorp.net/1000_Watt_Pure_Sine_Power_Inverter_12_Volt.html
I've been thinking about buying a pure sine inverter to install on half of the cabin circuits (kitchen and bath) so we can charge things like lithium ion drills and so my wife can use her hair tools (snicker) which seem to not always work with mod sine (at least one hair iron won't work).  I've been thinking that since my AIMS 2500 Modified Sine inverter has performed so well that I could get a 1k Pure sine from them (come on look at that price!!!) and split the AC panel.

Thoughts?

I'm guessing all I'd have to do would be install a second set of cables from the battery bank to the new inverter and then run a cable run from it to the panel and make sure the common bus is split left and right and then land it on the left side and the mod on the right side.

MountainDon

Problem: in the service panel the neutral should be bonded to the ground. Once and only once in the system. If you have two separated neutrals which are you going to bond to the ground? The bond is there for safety. I think if you made a bond from each of the separated neutral there is danger of frying something in either or both of the inverters. The electrical power of each will be out of phase and that is trouble. At least I think that will be an issue, not a licensed tech or electrical engineer.

Two panels with completely separated wiring would be safer I think. But best would be a larger sine wave inverter doing the whole thing.
Just because something has been done and has not failed, doesn't mean it is good design.


OlJarhead

Quote from: MountainDon on June 14, 2013, 10:49:18 AM
Problem: in the service panel the neutral should be bonded to the ground. Once and only once in the system. If you have two separated neutrals which are you going to bond to the ground? The bond is there for safety. I think if you made a bond from each of the separated neutral there is danger of frying something in either or both of the inverters. The electrical power of each will be out of phase and that is trouble. At least I think that will be an issue, not a licensed tech or electrical engineer.

Two panels with completely separated wiring would be safer I think. But best would be a larger sine wave inverter doing the whole thing.

I was wondering about that myself -- perhaps the 2k inverter would be better and just keep the 2.5k mod inverter as back up.

OlJarhead

OK I'm looking at two possible inverters from AIMS.  Both less expensive then any others I've found and my 2500 watt AIMS has been good to me so far.

One is a 3000 watt pure sine with no charger and 4500 watt surge, the other is a 4000 watt pure sine with 12000 watt surge and a charger.

The one with the charge will start a generator but at 10.5v on the bank and to me that's INSANE!  I'd rather be able to decide when the charger circuit is kicked and that to me ought to be at 50% or 80% discharge, not 100!

So, thoughts?

Perhaps I ought to get a generator auto-start switch (Zantrex makes one but it kicks at 11.5vdc which to me is too low still) and the 3000watt inverter as that would save me the funds a 2000 or 3000 watt Honda with push button start would cost (which can be used in this fashion).

considerations

I don't have a gen that will "auto start",,,,but, I have a Magnum inverter 2012.  The "Low Battery Cut Out", which is when the house winks off  :-\, can be set.  The default is too low like you describe, but I can set it at a reasonable level...like Mountain Don recommends, at more than 12v. Maybe Magnum has a model that would tell a gen to fire up at some (also adjustable) level.  I think Redoverfarm has a gen that comes on automatically, maybe he will share if that setting is adjustable in his system.


OlJarhead

Saw they had one actually, after my post and I was impressed that they even gave wiring diagrams for various generators.  Problem is most of the less expensive ones don'thave auto chokes :(

I think I'm to need one of these puppies this winter.

Redoverfarm

#1113
Eric I do have a Magnum 4448 watt inverter/charger.  In addition I have a auto/start with a BMK (Battery Monitor Kit) .  I can preset my start feature with either SOC (State of charge) , Voltage or both.  It has worked very well.  Only downside if you can call it that is that there is a slight constant drain on the battery bank with the inverter needing power for monitoring, supply to the start battery charger on the generator and the generator controller.  But even with that the generator comes on every 3-4 days for about 2 hours.  The generator is a EcoGen (propane) by Generac 6000 watt.  I have had excellent support by Magnum and installation was fairly easy.  It was a little pricey but I feel that it was money well spent.  The main reason I went with Magnum was it only required one unit to supply 240 volts which I needed for my deep well pump.





OlJarhead

That's the generator I wanted but the price tag was quite a bit more then I'd like to pay....

For the price of the Generac I could install 1200AH of battery bank and add another solar panel and just run a generator on the weekends I'd imagine.


Redoverfarm

Quote from: OlJarhead on August 06, 2013, 11:04:54 PM
That's the generator I wanted but the price tag was quite a bit more then I'd like to pay....

For the price of the Generac I could install 1200AH of battery bank and add another solar panel and just run a generator on the weekends I'd imagine.

Once I got to checking on the Generac line I found out that this is the only generator they would warranty since it was Off Grid.  The standbys were considerably cheaper but the warranty for off grid use canceled the warranty.  This was the only one that was made specificly for this purpose.  Standbys were $1K less.  There are two standby generators near mine that have bitten the dust because of extended use as off grid.  So really the extra cost is nothing compared to expensive repairs and being w/o a generator.  Plus it carries a 3 year warranty where the others are only 1 year I think.

OlJarhead

I'm starting to seriously consider this route.  My wife will kill me though!  d*

First order of business would be to convert to 24vdc instead of 12vdc which would just be a matter of changing cables around and switching the controller to 24v.  Then replacing my AIMS inverter with a newer Pure Sine inverter/charger (aims has a 2000watt one for $919 right now and some larger ones for a little more).  I'd have to add the Magnum auto gen start ($264) and generator ($3600 delivered) but for basically $5000 I'd have a backup generator capable of powering anything I'd run, a more efficient system capable of surging to 6kw and providing all the power I need, clean power at that, in the cabin and later in a shop (via gen) and I'd not have to worry about the system dying on me because I wasn't there to start the genny.

Only other thing to do would be to get a bigger propane tank installed for the generator.

Though I might also have to change out the battery bank as I do see it drop to 12.2v by morning sometimes.  That only happens when the fridge is running and then it bounces back so it's not as bad as it sound (I think anyway) and SG test suggest that's just under load but when the load is gone the batteries are still around 95% cap -- unless I'm smokin' something -- anyway, I'll have to look at batteries too as I might want to do that also.

So much to do!  OH and the EcoGen didn't have cold start kit last check -- I'd need that I think.

OlJarhead

The more I think about this the more I think it's the way to go.  I can get a 120 gallon tank or a 250 gallon tank (LP) delivered for FREE and only be charged $70 per year rental on it.  LP right now for residential is $1.89/gallon which is at least a buck less a gallon then I pay now!  Heck, that's just $189 to put 100 gallons in the tank which would last me a LONG time.

If I set the genny to come on at 12.10vdc on the battery bank then it would be at 50% of charge and would protect the system -- if the genny came on every morning I could lower that slightly since I've seen it drop there under load and I wouldn't want the genny to come on just because the fridge was running...so I could drop it to 60-80% of charge.  Something I'd have to play with.

Anyway, it's a $5k ticket and that's a ton but I think it would be worth it in the long run.  Only real issue is that I'm already looking at $1000 to get my water line run to the cabin and I still have to enclose the composting toilet....so much to do!

Redoverfarm

#1118
Eric here is a little something to go on.  It has been a couple years so prices might have gone up a little.  I might suggest that you invest in a BMK ( Battery Monitor Kit).  It would take the guess work out and give the AGS a perameter to start.

Magnum MS4448PAE inverter 1 $2,160 $2,160

* 48 volts dc

* 4000 watts output

* 60-amp battery charger

Magnum MMP breaker panel 1 $550 $550

* 175-amp dc breaker

* 30-amp ac input/output/bypass breakers

Magnum MMP-MP mounting plate 1 $80 $80

Magnum ME-ARC50 advanced remote 1 $240 $240

Magnum BMK battery monitor kit 1 $150 $150

Magnum AGS - automatic generator start 1 $250 $250


Redoverfarm

Just to give you some idea.  I just had my 500 gal tank filled today and it took 189 gal.  The last time it was filled was last summer.  But I also have a frig and hot water heater on mine.  The hot water heater is just periodic but the frig stays on all summer.  You might check further on your tank rental.  Here if it is filled twice in one year there is no rental fee.  The Ecogen only uses .85gph @50% load. 


OlJarhead

Thanks -- I'll have to look at those and see what I'll need.  Hadn't thought of a panel but those costs aren't out of line and the AIMS inverter will save me $1k.

I'm looking at several things I need to do right now and the genny and start will be part of it I think.

OlJarhead

QuoteMagnum MS4448PAE inverter 1 $2,160 $2,160

* 48 volts dc

* 4000 watts output

* 60-amp battery charger

Magnum MMP breaker panel 1 $550 $550

* 175-amp dc breaker

* 30-amp ac input/output/bypass breakers

Magnum MMP-MP mounting plate 1 $80 $80

Magnum ME-ARC50 advanced remote 1 $240 $240

Magnum BMK battery monitor kit 1 $150 $150

Magnum AGS - automatic generator start 1 $250 $250

I have the Midnight Solar MNDC breaker panel (I think the 250amp breaker) with lightening protector and breakers (60a I think but I planned on switching one to an 80a which I have but didn't install yet).

Likely I'll go with AIMS 24v 3000 watt Inverter/Charger with 60A charger it runs at 88% nominal efficiency and line mode is 95% with 10% THD (seems a little high but then for nearly half the price I can't complain)

I won't need a battery monitor as I can connect my PC to the charge controller so will be able to see what's going on that way without much trouble.  These days I just look now and again though I might like an indoor battery meter just so I can see what the bank is doing without looking at the PC or the box.  Need to look into that and see if it's worth going that route or just using Morningstars.

The wife approved the ECOGEN (whoohoo!) so I'll get the Magnum Auto start kit for it and set that at 12.1vdc/24.2vdc with hopes that it won't start the genny daily there!  I want to be sure the bank isn't abused though and if the genny has to run a LOT then I'll have a good excuse to upgrade the panels and battery bank :) and with running 24v I could crank up the panel wattage and battery bank without worry :)

My neighbor uses a 1000AH cat battery with about 500watts of panels on a tracker (so equal to maybe 625max) and it stays above 70% charge during the week.  Then he runs his genny on weekends to top off the tank so to speak, and to run washers and dryers etc.  I may be able to do the same until I get a bigger system.



Redoverfarm

Only reason I recommended the BMK is that it will start/stop your generator without you being there.  At least that is the way that I have mine set up.

OlJarhead

Quote from: Redoverfarm on August 08, 2013, 12:01:43 PM
Only reason I recommended the BMK is that it will start/stop your generator without you being there.  At least that is the way that I have mine set up.

That's what Magnum ME-AGS-S does -- the BMK I think only works with their inverter whereas their auto start works off bank voltage only.  The AIMS inverter will sense the incoming generator power (AC) and transfer to it for the cabin power and charge the batteries.  When the genny cuts out after two hours (assuming the bank is back up to acceptable level) then the inverter will transfer back with a 10msec transfer time which is usually enough to prevent even a computer from dropping :)\

QuoteThe ME-AGS-S is the 'standalone' version of Magnum Energy's Automatic Generator Start (AGS) controllers.

This auto generator start controller can automatically start your generator based on battery voltage or high temperature. Adjustable settings include: run time, start volts DC, start temp, quiet time, and 24 hour clock.

OlJarhead

http://www.firemountainsolar.com/manufacturer/kohler/kohler-8-5-res-residential-backup-generator/
Anyone know anything about these off Grid Kholer generators?  I've got pricing on an 8.5kw LP off grid genny set up just like the generac but not as quiet (65db vs 52db) that puts it about $600 less after shipping etc.