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AWG WIRE SIZE - 200Ft ? - Voltage Drop

J

JUMPSTART

New Member
Joined
Apr 27, 2024
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Location
Warrington, PA USA
Plans are 2S2P / 4 485W Bifacial Panels / Ground Mount / 190 ft run! / 1" Shedule 80 PVC (some areas) (Avails about 7/8" I.D.)... Currently 1 Inline 15A Fuse only at generator.

PER PANEL: SCT
Voc - 53.63
Isc - 11.16

Panel Label (Attached)
Spec Sheet / Temp Coefficiency etc - https://es-media-prod.s3.amazonaws...._XL-G10.3-BFG_475-490_2021-08_Rev01_NA_11.pdf


I am trying to learn but using calculators... Seem to have factored 4 AWG ...or... 25mm sq -- Not sure PV Wire or plain ol THHN? ... Would probably spring for the right stuff: #4 PV at $500

I probably should pay for a quote (just engineering) but I think it's amazing if you guys who know what you're doing should help. Like myself there is some kind of satisfaction one gets.

Similar To DELTA PRO (Max Inputs): 150V / 15A / 2,100W

FUTURE (More Panels) .... I will most likely do the right way and do a real system! and not play with this "All In One" (OUPES Mega 3)

My original plans were to mount these close by but will try to go behind garage which is my rough calculation of an over shot 186 ft. Of course I will pull a measuring string before any wire purchase. (probably less distance but why not max) ...Most likely Ground Mount, Conduit Underground, LB, Up Exterior Wall, LB, Bare Garage Ceiling... Underground through spare 1" PVC previous for any extras.

PANELS DO WELL! 4 - 485W (2S2P) (50 ft Run) South (Sun well off to west, behind trees!)
..... 195 WATTS / 90 VOLTS !

...Thanks you guys for any time you would freely give of yourself and calculations.
 

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It's hard to do 150v max over long distance, it would really be best in 4S over 10 awg.

If you had to run 2s2p over this distance I would relent and say it should be 8 awg.
 
DavidAmon said:
I believe the national electric code is to upgrade the wire by 1 size for every 100 feet of run.
Click to expand...
That's typical. Pretty much at 100 ft your cord now has the resistance of the wire size smaller so we up 1 to balance. (DC a different story?) ... DC does not go far! One of the reasons we went AC.
 
As @hwy17 mentioned, there is no requirement for voltage drop in a pv circuit, its not voltage critical. You can worry about it if you want to but it will result in giant wire with not much gain.

Use Ampacity charts to be sure the wire can carry the current, then you can bump up a size there if you want. For that 2s2p carrying at most 22.3 A, you can use 10awg. Anything larger is at your discretion. Not sure the benefits outweigh the cost after 8awg.

"PANELS DO WELL! 4 - 485W (2S2P) (50 ft Run) South (Sun well off to west, behind trees!)
..... 195 WATTS / 90 VOLTS !"
Are you saying after a 50ft run you are only pulling 195 watts? Thats terrible for a 1940w array. Something is wrong, hopefully a typo.
 
seneysolar said:
As @hwy17 mentioned, there is no requirement for voltage drop in a pv circuit, its not voltage critical. You can worry about it if you want to but it will result in giant wire with not much gain.

Use Ampacity charts to be sure the wire can carry the current, then you can bump up a size there if you want. For that 2s2p carrying at most 22.3 A, you can use 10awg. Anything larger is at your discretion. Not sure the benefits outweigh the cost after 8awg.

"PANELS DO WELL! 4 - 485W (2S2P) (50 ft Run) South (Sun well off to west, behind trees!)
..... 195 WATTS / 90 VOLTS !"
Are you saying after a 50ft run you are only pulling 195 watts? Thats terrible for a 1940w array. Something is wrong, hopefully a typo.
Click to expand...
Wow! ... Never knew. --- So: Perhaps I can size wire ampacity (for parallel) of the most panels I think I will ever own right? (this way my wire is covered for any future) EX: 8 of these monsters (In parallel) 11.16 A X 8 = 90A (Would = a #4 THHN).... Of course one doesn't have to do that.

ANOTHER QUESTION: CABLE TYPE? - Would the infamous THHN Conductor suffice? (by the way a #14 THHN = 25A.... Not many know that and assume always "small conductor rules at 15A)

Is there any INDUCTION (thin insulation on these THHNs) I should be mindful of?
.... or do I just go with Thick Insulation Tinned Solar Wire.

By the way ,... My 195W ... My panels were totally in the shade with the sun way off to the side (and behind trees). I figured that was pretty impressive when I get these things in full sun! ....(when some of the people with their fold up panels, 200W, $800, in Texas, clouds, aimed at the sun, couldn't even generate 16W which was not even enough to initiate a charge from their Delta Pro) Apples to Oranges I know but it made me feel better I should sicko out with 4 485s for about $1,000. Part of the game is to actually "do" something should the SHTF.
 
JUMPSTART said:
Wow! ... Never knew. --- So: Perhaps I can size wire ampacity (for parallel) of the most panels I think I will ever own right? (this way my wire is covered for any future) EX: 8 of these monsters (In parallel) 11.16 A X 8 = 90A (Would = a #4 THHN).... Of course one doesn't have to do that.
Click to expand...
You likely wont find a mppt that can take that kind of input current.
JUMPSTART said:
ANOTHER QUESTION: CABLE TYPE? - Would the infamous THHN Conductor suffice? (by the way a #14 THHN = 25A.... Not many know that and assume always "small conductor rules at 15A)
Click to expand...
If running in conduit, THHN is fine. If you want to direct bury you can use UF-B. I prefer xx/2 UF-B because it includes a ground wire. PV wire is sometimes worth while because it can be exposed to sunlight and direct bury if needed, its also available in higher strand count if needed.
JUMPSTART said:
Is there any INDUCTION (thin insulation on these THHNs) I should be mindful of?
Click to expand...
No
JUMPSTART said:
.... or do I just go with Thick Insulation Tinned Solar Wire.

By the way ,... My 195W ... My panels were totally in the shade with the sun way off to the side (and behind trees). I figured that was pretty impressive when I get these things in full sun! ....(when some of the people with their fold up panels, 200W, $800, in Texas, clouds, aimed at the sun, couldn't even generate 16W which was not even enough to initiate a charge from their Delta Pro) Apples to Oranges I know but it made me feel better I should sicko out with 4 485s for about $1,000. Part of the game is to actually "do" something should the SHTF.
Click to expand...
Thats good, if that was full sun id be worrried.
 
seneysolar said:
You likely wont find a mppt that can take that kind of input current.

If running in conduit, THHN is fine. If you want to direct bury you can use UF-B. I prefer xx/2 UF-B because it includes a ground wire. PV wire is sometimes worth while because it can be exposed to sunlight and direct bury if needed, its also available in higher strand count if needed.

No

Thats good, if that was full sun id be worrried.
Click to expand...
Thanks.
Current "INPUT? (To charge controller) -- No Such Thing. "Amps" is not a "thing", it's a "happening". The charge controller can only pull what it does. ...This is what was told to me. --- Voltage (Electrical "Pressure") we know is a different animal and critical.
Perhaps you meant: "Pull" that kind of current ...available anyway?

THHN - Yeah, to my knowledge a copper conductor is a copper conductor (Except for purity or tighter stranding/flexability)(so my next wonder might be why they "tin" PV wire? ...lol... Research shows: Tin Prevent Copper Oxidation) I guess the thicker jacket on PV wire is for durability. --

Looks like (to avoid hassel) 1" Schedule 40 PVC Conduit (with some schedule 80 which is thicker (above ground / protection from physical damage... but also thinner I.D. now) I will pull unconnected wire,... install MC4 later. ...Which now poses another: I have only MC4 : 2.5 mm, 4.0 mm, 6.0 mm = 14 , 12, 10 AWG .... Another (Weak Link) Solar Generator Input (15 A) ANDERSON 14 AWG.... I did purchase Andersons / Crimpers 15A (16,18,20 AWG) - 30A (12,14 AWG) - 45A (10,12 AWG) ...Looks like the Anderson allows 10 & 12 guage to hit 45 Amps anyway.
----- Opens up another set of tools to go any thicker than 10 AWG. .... I knew this would get deeper.
 
JUMPSTART said:
Thanks.
Current "INPUT? (To charge controller) -- No Such Thing. "Amps" is not a "thing", it's a "happening". The charge controller can only pull what it does. ...This is what was told to me. --- Voltage (Electrical "Pressure") we know is a different animal and critical.
Perhaps you meant: "Pull" that kind of current ...available anyway?
Click to expand...
Your example of 8 strings at 90A to a single charge controller is what i was referring to. That would be pointless. If you wanted to future proof your wire run. Just run multiple sets of smaller wire, not one set of big wire.

Many of the large AIO units have 2-3 mppt inputs and they are high voltage (400+) for larger strings.
 
seneysolar said:
Your example of 8 strings at 90A to a single charge controller is what i was referring to. That would be pointless. If you wanted to future proof your wire run. Just run multiple sets of smaller wire, not one set of big wire.

Many of the large AIO units have 2-3 mppt inputs and they are high voltage (400+) for larger strings.
Click to expand...
Oh, OK. --- Thing is I already have the 1" conduit in the ground (but also another spare). I fed the garage a long time ago with 2 1/4" and two 1"... ( Panel ground mount / Conduit not even installed behind the garage yet, ...Suppose if I bury this guy I'll oversize it. /// Thanks,... didn't know a "real" charge controller probably has a built in bus,... They don't expect huge conductors and just allow an add on to run an additional. Good to know.
 
Sub ((( FINAL )))
...Pretty much committed. At least my solar end / Run into house - 3% Voltage Drop (@ approx 100 V) is ok.
** 4 - 485W Bifacial - https://us.qcells.com/q-peak-duo-xl-g10-bfg/
** EG4 GROUND MOUNT - https://renewableoutdoors.com/produ...ack-kit-4-panel-ground-mount-adjustable-angle
#4 AWG
COMBINER BOX???..... Next a Combiner Box (or simple junction box)... #4 AWG ... Might have to just do a simple busbar or if space allows, a busbar to join my #4s out. I'm doubting the standard combiner boxes will even accept a #4... (and I sure ain't buying something $)
... An additional rainproof box could also house the bus below. At least I have a disconnect / 20 A fuses.

COMBINER BOX? (#4 ?) :

signaturesolar.com

ECO-WORTHY 4 String PV Combiner Box | 4 x 15A Fuse

Signature Solar provides solar panels, off-grid solar systems, grid-tie, and hybrid systems. Quality solar inverters, bifacial solar panels, complete solar kits, solar batteries. Featuring brands such as EG4 Electronics with their solar battery, LifePower4 and EG4 LLifePower4 and EG4 LL
signaturesolar.com signaturesolar.com

SIMPLE ? (really I will finally have 2 MC4s when said and done) - https://www.amazon.com/ENZPOWER-System-Combiner-Isolator-Connector/dp/B0761WZXXR

BETTER QUALITY DICONNECT - https://practicalpreppers.com/product/imo-4-pole-25-amp-dc-disconnect/
.... Still checking some out.
 
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