series/parallel PV wiring clarification

Re: series/parallel PV wiring clarification

krharley wrote: »

ok, need help trying to read the kill-o-watt meter. i'm running it through the extension cord coming from the generator. 4 times readings
1st day-118 v/amp 2.78/233 watts 2:40 .6 L
2nd day- 1.45 amps /14.6 watts 166 watts 2 kwh 00:08 .89 PF
3rd day- 2.86 amps 246 watts 340 VA .72 PP 0.14 kwh
4th day- kwh time 3:59 118.5 volts 2.47 amps 195 watts 292 VA 0.66 PA .07 kwh 4:04 kwh

I am having a hard time understanding what you wrote up there... I am not sure if you are miss-reading the meter, or if the generator is causing the meter to be confused (depending on the model of KaW meter, when you cut AC power, they reset. Some models have batteries that keep readings--Although, you can only read the the LCD when they have AC power, as I recall).

Generally, the readings should be something like this. The first list are "real time" measurements--No storage or long term average--Just what is happening "this second":

118 VAC (line voltage)
1.45 Amps (line current from generator)
171 VA (volts*amps)
0.8 PF (power factor)
137 Watts (VA*PF)

And these two are long term measurements:
0.685 kWatt*Hours (average Watts * # of hours * 1/1,000 = kWH)
05:00 Hours (hours meter has been running/plug into AC power

I do not see a lot of consistent readings from day to day.

that's without the A/C because i know it wont run that too. when the sun goes down of course all my numbers start going backwards too which is depressing because it goes so fast. if the sun is out next day, it charges right back up. my hydro battery checker is all good in the high red numbers all 4 batteries balanced-very pleased with that.

What are you using to measure your DC loads/charging (a Battery Monitor)?

And does you hydrometer actually give specific gravity values (such as 1.265)? Make sure you rise out the hydrometer with distilled water before you put it away for the day. They can get sticky/gummy inside and the float will stick if the are put away with electrolyte inside.

my power bright 2300 has been clicking off after hooking up the GT panels. it will go to 29.9 for so long and i have everything on ,guess i need to get a small heater to turn on for a few seconds- that all it would take because its a MSW and it also doesn't reset itself. so if i'm not home, and sun's out that's it. and even then as soon as sun goes down even with no load the cc goes to yellow, it doe stay their all night. only a few times it went to red led, but still re-charged quickly.

29.9 volts is pretty high for flooded cell lead acid batteries to be held at "absorb" charging voltage... Are you using a lot of distilled water every month to refill the batteries? Your solar charge controller may be running a bit high on the charging voltage.

Yes, for many off grid inverters, they will "fault" on 30 volts or more on the 24 VDC battery bus. Lead Acid flooded cell storage batteries really need around 30-32 volts to "equalize", and many AC inverters will fault (you can find some brands/models of better units that will not fault).

i still don't have a battery charger. been looking for a good one, but will wait because i think i need a better inverter- like you suggested before the samlex. i could hard wire it. i would like one with a charger in it and a reset. i think its too low. maybe 33 ?v would be better for me??

If you live in sub freezing weather and the battery bank can approach freezing--Then yes, you really need something more than 30 VDC as the inverter cutoff voltage for a 24 volt battery bank (as the batteries get colder, their charging voltage rises).

i measure 54-55 volts today, yet it was cloudy, but that"s about average if i remember right coming from the panels. does that sound right to you should it be 55- 60 volts measured with a multimeter ? down to my CC is where i took the reading.

What kind of solar charge controller do you have? The solar array voltage is pretty variable depending on the type of charge controller and what mode it is in. It sounds like you have two Vmp~30 volt panels in series with a MPPT type charge controller.

-Bill

Re: series/parallel PV wiring clarification

krharley wrote: »

right about the Kill-o-watt meter. mine only works plugged in to A/C. so i called myself trying to use the clock.so i just started writing them all down when i first plug in then when i go to bed, but i think i forgot a few times before i turned it off. i know they are all different but i'm having everything i have-plugged in. sometimes a light i might turn off after a while. so i was thinking i could get an average, but i'm too confused now. that was the only one available at the Lowes in my area. it certainly would be better if their was a back-up battery to hold the reading. its a small chest freezer,small fridge, ceiling fan with light kit, small tv 19", and my laptop with router.and another light i turn on/off at my bed. thats is everything i own. maybe the readings are different with the 2 compressors cycling on/off. i don't know.

Depending on their actual power consumption... It is pretty easy to see that taking 2-4 kWH per day (guessing) if you run enough hours on the genset (more than just a couple hours per day).

during the day if the sun is willing its all on the solar till 4:00 pm. i have to un-plug as my cc goes into yellow mode with voltage of 25.5.it goes to 29.5 by 12:30-1:00 and i have to have everything on or the inverter will click off.then i'll start turning things off as sun acts accordingly. by 6:00 pm i run generator till 10:00. the inverter voltages goes down and the cc in yellow . i'v measured many times the voltage on battery bank vs inverter and their close enough. but i don't understand why they continue to go backwards with no load/ while using generator. i leave everything off until the a.m when sun comes back out and they quickly go to green on cc (MS MPPT 45 amp ) and i slowly plug stuff back up. fridge 1st, freezer 2nd, etc

If you are using the MorningStar TS 45 MPPT charge controller--You should double check the dip switches (or programming)... Normally, you should be able to keep the peak voltage around 29.0 volts or so.

i would have never figured out the V*A , or PF.

VA and PF are used to represent the difference between "work" (energy, Watts) and the "inefficient use of current" by various loads (induction motors, many CFL/LED lights, and many switching power supplies). The "worse" the Power Factor, the heavier wire, inverters, and such needed to carry the "extra" current that "inefficient" loads use. We can talk more about that if you are interested.

i do not have a battery monitor yet, do you have a suggestion for me?

Unfortunately, Battery Monitors are not cheap, and they do need some programming/understanding how they work (they can drift over time/use if not properly programmed and/or the batteries are not fully recharged every few days to week or so). You might look at the Trimetric or Victron Battery Monitors as a starting point.

my hydro-meter is reading in the red-1.265-1.275- do i draw the water up twice. i have added about a shot glass amount to each cell for the last 3 months. i'm in Louisiana and its hot here. i have the EZ-RED sp101 model.i do rinse 3x after use- read that here some time ago.the post all look well,, i check and do have to tighten a little every month.

Sounds like your battery bank is OK... However, you should check every cell for SG every month or so--And look for cells that are "different" (high or low readings vs the rest of the cells).

I have 4 250 watt sharp panels hooked in series/parallel, so the vmp is 29.9 i think, but you think that sounds like only 2 panels? perhaps i have a problem at panels then. what should i be reading with the 4 GT series/parallel?

You probably have them connected with 2 panels in series (for 2x 30 Volts = Vmp~60 volts) and then the 2 strings in parallel (8.3 amps * 2 = 16.6 Amps Imp for the array). This would be the recommended configuration for charging a 24 volt battery bank.

-Bill