PV is about 65 feet from charge controller, what % of loss should i expect'

rgearhead
rgearhead Solar Expert Posts: 38 ✭
in General Solar Power Topics #1
Im running 6 gage the whole way .....
[URL="[IMG]http://i149.photobucket.com/albums/s62/rgearhead/5316c754-fb92-4734-a374-73a1f3df5f08_zpsea9fddec.jpg[/IMG]"]5316c754-fb92-4734-a374-73a1f3df5f08_zpsea9fddec.jpg[/URL]

the panel is'' what should i expect to loose of my 250watts ?
[URL="[IMG]http://i149.photobucket.com/albums/s62/rgearhead/ef4067f2-c5eb-4b16-b24b-6959d5e401b1_zpsb87f816c.jpg[/IMG]"]ef4067f2-c5eb-4b16-b24b-6959d5e401b1_zpsb87f816c.jpg[/URL]
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #2
    Re: PV is about 65 feet from charge controller, what % of loss should i expect'

    Less than 2% V-drop given the 30 Vmp 8 Imp 6 AWG wire and 65' distance.
    That's not even 5 Watts. You will probably lose more from heat and sun angle.
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  • rgearhead
    rgearhead Solar Expert Posts: 38 ✭
    #3
    Re: PV is about 65 feet from charge controller, what % of loss should i expect'

    Thanks Cariboo, another question if you will... I have 2 195 watt PVs that will be located in anther part of my yard 50 feet from where my solar charger (tri star mppt 45) will be, what would be best parallel or series and i do have more 6 gage....

    [URL="[IMG]http://i149.photobucket.com/albums/s62/rgearhead/c3ee8b7c-1713-4dc4-988c-baa8d9cdb5e0_zps7f423d15.jpg[/IMG]"]c3ee8b7c-1713-4dc4-988c-baa8d9cdb5e0_zps7f423d15.jpg[/URL]
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #4
    Re: PV is about 65 feet from charge controller, what % of loss should i expect'

    Whoa.
    You want to put the 195 Watt panels on the same controller as the 250 Watt panel?
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  • rgearhead
    rgearhead Solar Expert Posts: 38 ✭
    #5
    Re: PV is about 65 feet from charge controller, what % of loss should i expect'

    wish i could'' but the first mppt 45 can only take 600 watts max, I would be at 640 watts... wish i went with a mppt 60 right off the bat...Hmm is there any way i could throttle back some watts at one of the arrays to be at 600 watt max...


    thanks...
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #6
    Re: PV is about 65 feet from charge controller, what % of loss should i expect'

    ? :confused:
    I think we need some more details here. So far I register one 250 Watt panel on one controller. Now you've introduced two 195 Watt panels on ... another controller, right? So there's 640 Watts. On a 12 Volt system that would be 41 Amps which would work on the MS 45 MPPT. IF the panels were compatible.

    But the Vmp of 36 on the 195's is more than 10% over the Vmp of 30 on the 250 (20% in fact). What's more because the total Wattage is higher it would pull the array Voltage up bringing the Voltage above the Vmp point of the 250 Watt panel causing its current output to drop.

    If anyone is wondering I myself just tested this principle with two parallel arrays that have 16% Voltage difference with the higher Voltage array also the larger Watts. The difference between running them in parallel and running them on separate controllers was 24% drop in power over its full potential.

    What is the system Voltage, by the way? Because there can be problems both with not having high enough Vmp (as in the 250 on a 24 Volt system) or having too high a Vmp (two 195's in series on a 12 Volt system). The best configuration depends on the details.
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  • rgearhead
    rgearhead Solar Expert Posts: 38 ✭
    #7
    Re: PV is about 65 feet from charge controller, what % of loss should i expect'

    Ugh.... the 250 PV was a mistake that just ended up at my door, Im innocent I tells ya'''

    this whole project is mainly for emergency back up, and i could run a few lights, floor fan , ect,ect in the mean time while waiting for the emergency to arrive...
    what i have at the moment is the 3 panels above and 1 tri star mppt 45, the battery's are 6 sam club egc2' 230 AH wired series parallel for 12 volt inverter.

    I am now thinking of un-linking 2 of the battery's to be just be for 12 volt items and a small 400 watt inverter, and have it run off the 250 watt and a charge controller, and let the other 4 battery's charge n run off the 2-195 (and i can add 1 more) to run my decent pure sine 1,800 watt 12 volt inverter..
    love to hear my alternatives ..

    thanks....
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  • rgearhead
    rgearhead Solar Expert Posts: 38 ✭
    #8
    Re: PV is about 65 feet from charge controller, what % of loss should i expect'

    Ugh'' this started out as a small emergency back up, we loose power once in awhile for short periods, and its nice to back up the fridge n freezers while grid down plus run some floor fans n lighs in the mean time...the 250 watt came to me as a mistake, but it's here and mounted, hope you can help me sort this all out....
    what i have thus far
    the 2- 195 PV's
    1- 250 pv'
    one Aims(cough) modified wave 2,000 watt, 12 volt
    one Dimensions pure wave 1,800 watt, 12 volt
    one tri star mppt 45
    6- sams club egc2 6 volt 230AH each...
    what are my options with this mess...
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #9
    Re: PV is about 65 feet from charge controller, what % of loss should i expect'

    Short form: how much more money do you want to spend? That opens up lots of options. :D
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  • rgearhead
    rgearhead Solar Expert Posts: 38 ✭
    #10
    Re: PV is about 65 feet from charge controller, what % of loss should i expect'

    he he, my wifey sleeps with the purse under one arm and one eye open, if i dumped this on you door step over night , what would you do to make this ,emm use full ?? PS, mo hill into mountain is coming to mind...


    thanks, again n again....
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  • vtmaps
    vtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    #11
    Re: PV is about 65 feet from charge controller, what % of loss should i expect'
    rgearhead wrote: »
    I am now thinking of un-linking 2 of the battery's to be just be for 12 volt items and a small 400 watt inverter, and have it run off the 250 watt and a charge controller, and let the other 4 battery's charge n run off the 2-195 (and i can add 1 more) to run my decent pure sine 1,800 watt 12 volt inverter..

    This scheme seems to make sense... you will need another controller for the 195 watt panels. Another advantage of two systems is that it reduces the number of parallel batteries. (if you're not aware... parallel batteries are problematic).

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #12
    Re: PV is about 65 feet from charge controller, what % of loss should i expect'

    Yes; splitting it into two 12 Volt systems would be efficient, although requiring the purchase of another MPPT controller.

    Ditch the big AIMS inverter would be a good idea. Running a 24 Volt system would be a good idea (the 195 Watt panels could recharged that through a PWM controller). Buying matching panels and selling the one that doesn't fit would be a good idea.

    Or accepting the losses on the 250 Watt panel. Unfortunately with a 12 Volt system the array will be operating at the higher Voltage most all of the time because the battery Voltage is so much lower. With a 24 Volt system a 30 Vmp panel on a PWM controller could contribute during Bulk charging and would just fall off in current as battery Voltage came near Vmp leaving the 195 Watt panels to finish the charging.

    Bargains so often aren't.
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  • rgearhead
    rgearhead Solar Expert Posts: 38 ✭
    #13
    Re: PV is about 65 feet from charge controller, what % of loss should i expect'

    thanks so much guys.....I think I will work on getting the pole in the ground before frost comes and get the 2-195s mounted and wires run, then look into another charge controller then un-link one pair of Battery's, Basically having 2 small systems, and with 2 charge controller I could always add PV's down the road ....

    as for Aim's Im the guy who posted pic's of that Aims inverter that was hobbled together with the bathroom calk n zip tied internal cooling fan, So ya im now a HUGE fan of aims......
    :p
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