Slightly over 5000w on an FM80?

Dave Angelini wrote: »

The most obvious to me is to not need all that power by using efficient cooling. They are getting 30 SEER these days.

My mini-splits are only a year old and they are either 22 or 24 seer (I can't remember exactly).
And my cooling usage is less than half of my total usage each month; which of course is still a lot, but it has been crazy hot this year.
I have KWH meters on each AC and on the main supply to the house so I can monitor everything.

Date
Total Avg/Day
AC-1 Day Avg
AC-2 Day Avg
AC-3 Day Avg
AC Use Total Avg/Day
Non AC Use Total Avg/Day


09/24/14








10/01/14
17.0
2.9
2.1
2.71
7.7
9.3


10/31/14
18.1
1.6
1.4
2.17
5.1
13.0


12/02/14
17.8
1.3
1.5
1.22
4.0
13.7


01/05/15
19.4
0.6
1.2
0.59
2.4
17.0


02/01/15
19.6
0.0
0.8
0.04
0.9
18.7


03/01/15
20.0
0.1
0.8
0.04
0.9
19.1


04/01/15
21.1
1.0
1.5
0.13
2.6
18.5


05/01/15
24.9
1.5
2.7
1.43
5.6
19.3


06/01/15
26.6
1.6
2.9
2.94
7.4
19.2


07/01/15
29.2
2.1
3.3
4.37
9.8
19.4


08/01/15
29.1
2.8
3.2
3.90
9.9
19.2


Not sure how much power I would actually save if it were a 30seer unit? Not to mention the cost of those 30 seer units are way up there.
Wonder if there is any kind of formula to determine the energy use/saving for one seer vs another?

Dave Angelini wrote: »

Well you spoke of using a window unit and so I assumed that was your method.

Yes, I was thinking of adding a small one to the power room for in the summer because it tends to get a bit hot in there.

Dave Angelini wrote: »

Looking at your data it looks like your main issue is not the cooling load but your other loads. Most off-grid homes that have done their energy efficiency homework use around 4 KWH per day without space conditioning loads. The last few months you are using over 9KWH each month for your non cooling loads?
Maybe that includes battery charging?

No, battery charging is a separate meter from the generator and that does not pass thru these meters.
I am as energy efficient as I can be. Modern Fridge and Chest freezer, LED lights, etc. The chest freezer is in a non-air conditioned out-building, which I am sure adds a bit to the energy consumption. I should prolly measure the usage of that to find out for sure. I just don't have room for it anywhere in the "main house".

However I also have a 20' pool, and even though it is an EE pump, that still contributes to prolly about 2-3kwh per day (maybe more, I should measure it someday).
Plus I work from home, and have several "servers" running 24/7.
So unless I decide to "rough it", I don't think I am going to be able to reduce my base usage anymore.

Dave Angelini wrote: »

I find your data interesting, how is it that you know each of the mini-splits usage and do not know what the pool pump uses?

Well, I bought some actual power meters (electric company type on ebay) and connected them to the feed going into each of the mini-splits. Since they are 240v, it was easier and cheap to use those meters. I think I got the meters for $25 each and the meter box was maybe $25 at home depot.

My pool and other circuits are all combined on the other power meter that feeds everything (including the ac power).

I just picked up a few of these http://www.ebay.com/itm/131515288117?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT, and am going to add them to selected circuits in the house (pool, computer room, kitchen, living room, well pumps) that way I can narrow down where the rest of the usage is. They are cheap enough ($12) and use current transformers so they will be really easy to wire into my main panel on individual circuits. I'll just fabricate a small enclosure next to the main panel to hold the meters.

And I decided on 12 more panels and just said to hell with it and bought another FM80. I'll move one set of 3 of the existing panels plus the 12 new ones to the new FM80 and that will keep each of the 3 controller's wattage around 4k.

Everything gets delivered tomorrow so it will be a fun next couple of days

vtmaps wrote: »

I looked at the ebay link and under 'Specifications' is this:

• Dual measurement of AC voltage, AC current with AC current transformer (It can't be used for measuring the AC power converted from a DC power with an inverter)

Note: the bold text was bold in the specs.... I did not add it for emphasis. But I wonder why it won't work with an inverter... maybe they are worried about modified square wave inverters.

--vtMaps

Yeah I saw that too, but I am sure it is because, like you said, of the modified sine wave inverters. And many people are not smart enough to know the difference since they sell them modified-since wave inverters with all sorts of fancy different marketing terms/names now-a-days. So I guess it is easier for them to just put a blanket disclaimer on it. I'll let everyone know if there is an issue, but I highly doubt there will be any on my Outback inverters.

OK, project went awesome. Have the 12 new panels installed and the new string of 8 batteries added to the existing bank installed. Actually also finally got around to having Trojan replace that one battery that was weak from the first batch almost a year ago.  They are adjusting nicely and its been about a week and they are almost to the point of being within 1 or 2 amps of equal draw with the old banks.


Yes I know the problem in the picture above. I am OCD also  I will add 9 more panels in a couple of weeks to the top right to make it even  I ended up buying another FM80 so I was not over-maxing the 2 I already had. Had to swap out the 2-pole GFDI to a 4-pole GFDI, so I have an extra 2-pole GFDI that is less than a year old if anyone wants to buy it. So now I run 3 arrays, 3780w, 4020w, 3375w for a total of 11,175w into a total of 1110ah of battery in 3 strings. Actually today I peaked a 10,498w and 160amps. Right after a short rain shower and then some nice bright sun on the cool panels. And when I add the 9 OCD panels to the top right, I will be at 5100w, 4050w, 4140w for a total of 13,290w.

I also added a somewhat EE window A/C unit to the power room since in the summer it was getting WAY too hot in there even with the exhaust fans. A couple of times this summer in extreme 108 degree, 99% humidity days, I had an inverter shut down for over-temp. Now with the A/C unit in there, it stays at 78 degrees and only consumes about 2kwh per day to run it. I'm sure that will pay off in the fact that my batteries and equipment will last longer with the cooler temps and the lower humidity. Plus it's a nice room to sneak off into to cool myself off for a few minutes when I am out working on the yard
 
The picture below I took the in the early evening when my first 2 existing banks were charged and then connected the new bank which needed to be "topped off"  - That is why the first 2 banks are only drawing 2A and the new bank is drawing 35A.  Like I said, it's a week later now and they are all within 1 or 2 or 3 amps of each other both charging and discharging. Battery interconnects and bus connects are all exactly the same length so I should always be right-on in the future.


And I also got all the meters (from the above earlier post) connected to the main panel. They work great.  Ironically after I got the first one and tested it (it took about 10 days - free shipping), I placed the 2nd order for 18 more and they shipped them Free-DHL so I had them in 3 days from China! Attached are some pictures. I likely have about $300 total into the new "meters panel" (including boxes and wire) but the data it will give me is worth more than that. This pictures was taken about an hour after they were all installed.



Actually my "over-engineering" and having meters on each of my A/C units paid off recently.

I was noticing a significant increase in daily consumption (almost 25% from low 30kwh per day to 40+kwh per day). Using daily readings from the meters, I narrowed it down to one of my mini-splits. Upon further investigation, it turns out about a month ago it started slowly leaking Freon and now it was to the point of freezing part of the inside coil, thus causing it to run almost non-stop at almost 9kwh per day! Without the individual meters I likely would not have found out where it was coming from. Long story short, one of the flare nuts on the refrigerant lines had a casting flaw and actually cracked in 3 places causing the slow leak. Fixed now and back to being cool and using only about 2.5kwh per day.

So, sorry for the delay in letting everyone know, I got busy on another project when I broke an axle on my swamp buggy I had just finished building. So that consumed a bit of my free time; planning on changing them out to 2.5ton axles.

mike95490 said:

Nice place to stash 4 kids when the seats are all full !!

Yeah, that's the "E" Ticket ride
-- I'm dating myself by making that comment, wonder who else "gets it"

BilljustBill said:

A picture is worth a thousand questions!  What a setup!  Do you think you could have gone to a smaller A/C wall unit?  Here in North Central Texas, summer temps are hot and I'm afraid the heat from two GVFX3524 Outbacks and three FM80's is going to too high for just blowing DC fans.

 I was wondering how you handle your homeowner's policy?  Do you have a special Ryder to cover them?  Average increase to your policy?

I appreciate the knowledge as I'll soon be adding/addressing those issues with a 5k off grid system.

Thanks,

Bill

That's the smallest wall AC unit I could find that has "digital" temperature control and Energy Star settings. It's only a 6500BTU. The smallest AC units I have ever seen period are 5000, and they are the old manual style.

And Insurance, LOL, not a chance. Can't get insurance out here at all for anything. When you need a 4x4 to get down the 5 mile long "road/trail" to the property, and have to go thru 2 locked gates, that pretty much guarantees that the fire department won't be able to get to you. We are actually serviced by Forestry fire service and they are not really "first responders" anyways.