Advice on RV Set up & Wiring?

[sensij]

Sensi J,
So I did the math wrong on the inverter draw, it takes 1.45A x 12V = 17.4 Watts?

If so what is the total draw for 24 hours then; 17.4W x 24hrs = 417.6 KHw?


On the Epsolar Tracer mppt controller does anybody know if it has amp limiting, volt controls, and is a3 stage?

17.4 W * 24 H = 417.6 Wh = 0.4176 kWh.

The Epsolar definitely limits amps to whatever it is rated for, I don't think the amp limit can be set lower. It is 3 stage (4 stage, counting EQ). For voltages, you can choose a pre-programmed battery profile, or set your own profile in the range of 9 - 17 V. Absorb (they call it boost) can only be set to a max of 3 hours, is not current based.

[Sunking]

So I did the math wrong on the inverter draw, it takes 1.45A x 12V = 17.4 Watts?

Correct you are burning 17.4 watts as waste heat

If so what is the total draw for 24 hours then; 17.4W x 24hrs = 417.6 KHw?

Correct again you will use 418 watt hours a day off your battery as waste heat. To to make the Inverter warm requires a 12 volt 40 AH battery you never get to use.

On the Epsolar Tracer mppt controller does anybody know if it has amp limiting, volt controls, and is a3 stage?

You would not want it if it did.Stage 3 is Float and no current is going to the battery as it has already finished charging. Float or stage 3 is to keep the battery charged up, and if you equipment demands power will come from the panels and not the battery assuming there is sun. Limit the current and you defeat the whole purpose.

[Wrybread]

Have you confirmed the 17 watts overhead from your inverter by measuring the draw? That's *really high* for inverters. Most inverters typically pull around 3 or 4 watts when at idle. My Xantrex 600 for example pulls around 3 watts when not in use. Here's a page where someone measured the real world consumption of a bunch of different inverters:

http://2manytoyz.com/noload.html

In real world usage, that rating probably refers to an initial spike. If it's pulling that much power at idle constantly, I'd seriously consider getting a more modern inverter.

[SunEagle]

Have you confirmed the 17 watts overhead from your inverter by measuring the draw? That's *really high* for inverters. Most inverters typically pull around 3 or 4 watts when at idle. My Xantrex 600 for example pulls around 3 watts when not in use. Here's a page where someone measured the real world consumption of a bunch of different inverters:

http://2manytoyz.com/noload.html

In real world usage, that rating probably refers to an initial spike. If it's pulling that much power at idle constantly, I'd seriously consider getting a more modern inverter.

Some inverters are pretty inefficient especially the larger wattage ones that are not from a quality manufacturer.

I have the Xantrex 600 and it is a quality inverter which I also recommend to people.

[Sunking]

Additionally cheap inverters do not achieve specified efficiency until they are at full power. At say 30% power rating, or 300 watts on a 1000 watt inverter efficiency can be 60% means you are burning 500 watts of battery power to get 300 watts out of the Inverter. You get what you pay for.

[Carv]

Have you confirmed the 17 watts overhead from your inverter by measuring the draw? That's *really high* for inverters. Most inverters typically pull around 3 or 4 watts when at idle. My Xantrex 600 for example pulls around 3 watts when not in use. Here's a page where someone measured the real world consumption of a bunch of different inverters:

http://2manytoyz.com/noload.html

In real world usage, that rating probably refers to an initial spike. If it's pulling that much power at idle constantly, I'd seriously consider getting a more modern inverter.

Interesting, I'd bet like the fridge everybody was freaking out abou, it probably uses much less than it's rater for. I did read the ratings again and it says it uses 14.4W when with no load and 1.45W in sleep mode and no load, so if it is true, unless it's in sleep mode it uses just as much as my fridge everyday 345 watts a day.

Is there a way to measure the actual power consumed by the interter if I run a system test with the fridge running off the inverter?



If I could make the power saving mode work I could run the fridge and it'd only consume 35 watts a day which would work. Here's the problem, on the power saving mode I can adjust the load sensing from 20W up to 115W to kick on BUT since I'm running a thermostat control on the fridge, there seems to be a "no power" loop using sleep mode where the fridge won't turn on and wake the inverter out of sleep mode. The fridge won't run and read the tempature since there is no power being sent to the thermostat. Since there is no power running the thermostat it fails to turn on the fridge AND therefore the inverter isn't brought out of sleep mode to send power to the fridge. Is there a way to make this work since the fridge and it's thermostat run off the inverter?



Thanks

[bcroe]

Interesting, I'd bet like the fridge everybody was freaking out abou, it probably uses much less than it's rater for. I did read the ratings again and it says it uses 14.4W when with no load and 1.45W in sleep mode and no load, so if it is true, unless it's in sleep mode it uses just as much as my fridge everyday 345KhW.

If I could make the power saving mode work I could run the fridge and it'd only consume 35 Khw a day which would work. Here's the problem, on the power saving mode I can adjust the load sensing from 20W up to 115W to kick on BUT since I'm running a thermostat control on the fridge, there seems to be a "no power" loop using sleep mode where the fridge won't turn on and wake the inverter out of sleep mode. The fridge won't run and read the tempature since there is no power being sent to the thermostat. Since there is no power running the thermostat it fails to turn on the fridge AND therefore the inverter isn't brought out of sleep mode to send power to the fridge. Is there a way to make this work since the fridge and it's thermostat run off the inverter?
Thanks

You need to go back and edit that post to get ALL your units right. 14.4W X 24 H = 345 WH, NOT 345 KWH. We are
into math, not mind reading what you really meant. Bruce Roe

[Carv]

Can I run the Yingli YGE-U 72 cell series with a PMW controller?


I was told this is a 24V nominal panel that can be ran with a PMW controller.

I thinking that since I'm 12V that running this panel with a PMW would not work on my system?


Heres the specs: Yingli YGE -72 Cell Specs.jpg

[Carv]

So I also discovered that Epver cameout with a 2nd generation Tracer MPPT controller:

http://www.ebay.com/itm/EPEVER-MPPT-...1RFmX89Hyc6Eag

Is this a better controller than the 1st generation / does anybody know the differences (besides the case)?


Here's the details on the new one: Epver -Tracer Gen 2 (BN4215BN) -40A Specs -1.jpg

[sensij]

The 150 Voc limit (vs 100 Voc on the 4210A) is nice if you want to load up more aggressively on panels. I can see it is generally more expensive than the 4210A, but beyond that, the functionality looks the same,

You are correct, putting a 72 cell panel through a PWM controller to a 12 V battery is wasteful. Under great conditions, you might get only 100 W or so from that 300 W panel in that arrangement. (So there is no confusion... The Tracer series is mppt, not PWM, and would do fine with 72 cell panels)

[Carv]

Thanks sensi J for the quick answer


Ok so based on this I'm thinking I'm going to go with:
1) 2 Yingli YGE 60 cell series -245 to 250 watt range
-Max Voc is 38-38.4 each

If I go with the above set up and a generation 1 40A Epever Tracer MPPT, the max watts is 520W & 100 Voc and I'd be at 290-510W and 80 Voc so I'd be ok on both fronts even on cold mornings (righ?) BUT it charges at 40A and I have 2 centenial GC-2100 rated at 214AH, this takes me to a C/5 charge rate.

OR

Should I consider a a single 330W panel and a 30A CC which would get me to a C/7 charge rate instead which is better for the batteries?



I guess it comes down to either less PV watts and running my current batteries in an acceptable range OR knowing I'm going to end their life early and anticipate replacing them with 2 T-105's (which can accept down to C/1 according to sun king) down the road. Which leaves me having a better system now that will be upgraded down the road with better batteries that work better with the system.



On a side note I do not think I can run my inverter in sleep mode so I'll consume an estimated 770W a day for both fridge and inverter, this system should be able to replace this given it will be ran in a 5 hour rated location in December???

[sensij]

Thanks sensi J for the quick answer


Ok so based on this I'm thinking I'm going to go with:
1) 2 Yingli YGE 60 cell series -245 to 250 watt range
-Max Voc is 38-38.4 each

If I go with the above set up and a generation 1 40A Epever Tracer MPPT, the max watts is 520W & 100 Voc and I'd be at 290-510W and 80 Voc so I'd be ok on both fronts even on cold mornings (righ?) BUT it charges at 40A and I have 2 centenial GC-2100 rated at 214AH, this takes me to a C/5 charge rate.

OR

Should I consider a a single 330W panel and a 30A CC which would get me to a C/7 charge rate instead which is better for the batteries?

I guess it comes down to either less PV watts and running my current batteries in an acceptable range OR knowing I'm going to end their life early and anticipate replacing them with 2 T-105's (which can accept down to C/1 according to sun king) down the road. Which leaves me having a better system now that will be upgraded down the road with better batteries that work better with the system.

Why not both? Get the 500 W of panels, but stick with a 30 A CC so you don't hit your existing batteries too hard. Down the road, if you want to upgrade to 40 A and a bigger battery, you'll already have the panel power in place. In the meantime, as long as you use a good 30 A cc, it will never generate more than 30 A, even if the panels were capable of more under those conditions, so there is no risk to the CC or the batteries.

[Carv]

Why not both? Get the 500 W of panels, but stick with a 30 A CC so you don't hit your existing batteries too hard

Becuase if I go with the cheaper Epever it's limited to 390W on the 30A controller, and if I run 2 panels I'm at 500W.


Not sure what the Morningstar max panel watts is on a 30A CC BUT I can only find the Morningstar MPPT new and it's $400-$450 for the 45A so that's out of the question.


Based on 500Pvw what brand & model controllers do you recomend, obviously MPPT?

[sensij]

Becuase if I go with the cheaper Epever it's limited to 390W on the 30A controller, and if I run 2 panels I'm at 500W.

You are misunderstanding the specification. 390 W is the max power it will use to generate 30 A. The only way you can generate 390 W is to install an array rated larger than that. The bigger you go, the more hours per day you can generate that 30 A target. Look at page 10 of the Tracer manual (pdf page 13). It says the max array for the 30 A model is 1170 W. I wouldn't recommend going that high... that is a lot of wasted power on sunny days, but the point is that as long as you are under that value, and within the Voc and Isc limits, the controller is happy.

[Carv]

Cool, thanks Sensi J


So now that I know I can "over panel" the controller, I can now use either panel I was looking at so...

What is better a 60 cell 250W panel or a 72 cell 285W panel hooked up to a 30A/100Voc MPPT CC?

60 cell is 80 Voc & 72 cell is 90 Voc.