How can I correctly feed a 60 amp Renogy Controller Charger with eight 12 v 175 watt solar panels?

I am a bit confused... You have a long, detailed discussion that pretty much answered these questions:

https://forum.solar-electric.com/discussion/357595/need-help-setting-up-solar-electric-system-on-our-converted-bus-motor-home#latest

--As far as I can tell... Simply 4 panels in series (each trailer) x 2 trailers in parallel to an (over paneled) 60 amp MPPT controller charging at 12 volt battery bank.

You have other options (buying a second MPPT controller, etc)... But to keep costs down, this is the "optimum for you needs at this time".

The MPPT controller itself will limit its output to 60 Amps when charging your battery bank... And if the controller has "issues" (such as running hot during warm weather/poor ventilation), it will reduce the output current to prevent overheating.

The controller also has "limited output" based on the amount of solar energy from your array... If your array is producing 300 Watts because of clouds/poor sun angle in morning or evening, etc., it cannot produce more output power than the array is capable of providing. The controller will only output 300 Watts (300 watts/14.4 volts charging = 20.8 amps).

There is the issue of over paneling an MPPT controller... Having an array that produces more wattage than the MPPT controller can output.

Typically the math would be:

• 60 amps * 14.4 volts charging * 1/0.77 solar array deraring+controller losses = 1,122 Watt  "optimum" array typical "best case derated" harvest in warm weather (the 0.77 array+controller derating factor)

You have a a 1,400 Watt (STC) rated array--So there will be days where the array is capable of outputting more power (Watts) than your MPPT can "consume"... It is the nature of the beast. Nothing will "break". The MPPT controller will simply draw what it "needs" and/or can manage to charge your 12 volt battery bank/run your loads.

A good quality MPPT controller will allow over paneling (larger than XXX Watt array) because it has the capability of adjusting its output current to the battery bank based on its ratings and actual conditions. With your 2x700 Watt trailers (1,400 Watt total), there will be times that array will be capable of producing more than 60 Amps of charging current into your 12 volt battery bank. The MPPT controller will simply not take more Array Wattage than needed to charge the battery bank, up to its 60 amp max output rating.

There are limits to all things... Yes, a well designed 60 amp MPPT controller can be connected to a 100,000 Watt array--It is just that the wiring itself inside the controller could "catch fire" if the controller fails (all things eventually fail).

In this case, the MPPT controller is also designed to charge a 48 volt battery bank--Meaning that it can output 4x more Power (Watts) or (57.6 Volts charging * 60 amps = 3,456 Watts into battery bank) a much larger array and still be "safe" (MPPT controller solar array input rating). As long as you respect the other limits (such as maximum 140 VDC input rating).

-Bill

Bill, the forum is a "hobby", not a job... I do have a life (whatever that is) too so it may take a day or two for me to reply.

In your original discussion, I did go through the math for 1x vs 2x runs of 10 AWG cable... You will have less losses due to resistance with two 10 AWG runs back to the bus.
If you run 1x pair of 10 AWG @19.44 amps (two trailers in parallel on 1x 10 AWG cable run):
https://www.calculator.net/voltage-drop-calculator.html?necmaterial=copper&necwiresize=2&necconduit=pvc&necpf=0.99&material=copper&wiresize=0.4066&resistance=1.2&resistanceunit=okm&voltage=72&phase=dc&noofconductor=1&distance=100&distanceunit=feet&amperes=19.44&x=0&y=0&ctype=nec

Result

Voltage drop: 4.62
Voltage drop percentage: 6.42%
Voltage at the end: 67.38

Will a single run work? You will have 2x the losses because 1/2 the amount of copper... or ~34 Watts per trailer at "high noon" and full current/power draw... Or 64 Watts loss, or as a "solar panel"

• 64 Watts loss * 1/0.77 panel+controller losses = 83 Watts of solar panel "losses"

Or almost the equivalent of 1/2 the lost output of one of your 175 Watt panels using a single pair of 10 AWG cables... Of course, using 2x pairs of 10 AWG still have loses (i.e., 1/2 of 83 Watt panel equivalent, or ~41.5 watt panel equivalent).

If you paid a $1 per Watt for your panels, then you are "losing" ~$41.50 "worth" of solar panel power vs $xx.xx worth of 200 feet of 10 AWG cable...

A huge loss--No. The system will still be functional. Just less harvest...

With solar, we try for efficiency because these losses happen every (sunny) day. But for most people, running 4/0 cable 100 feet (for near zero voltage drop losses) while much lower losses--Just does not make financial sense.

3% cable losses... Pretty much "lost in the noise". You would be hard pressed to even "see" these losses in a day to day system. Over 10% losses. Can start to impact a system's performance.

What is it "worth" to you (more $$$ copper or more $$$ panels, or more $$$ genset fuel, or simply using 6% (or whatever) less power that day).

With off grid solar power--A system is always "over designed" to produce more power than "needed"... You are simply looking at a system that will produce "enough energy" during an average winter week, may produce 4x that amount of energy on a bright/clear/beautiful" summer's day. Vs a design that will work fine during summer, and leave you with dead batteries (or fuel costs for genset) during the winter.

Whether more panels for more generation, or more copper for less losses, or using less energy, or using more fuel for genset during winter weather-These are the trade-offs that only you can make.

-Bill

Bill,

In theory, all you have to do is wire nut (or use bus connectors, etc.) to simply connect the trailer's + connections together, and the - connections together... If you had thee or more trailers, you would use a Combiner box (circuit breakers or fuses) in the + leads to protect against short circuits (when three or more strings of panels are paralleled, the "series protection fuse" (probably something like 15 amps in your case--But always check the solar panel documentation for series protection fuse value) to protect one shorted panel from being fed power from the other parallel strings and starting a fire.

In practice, you might want to use a pair of switches (or circuit breakers in the + or + and - leads. The issue is that if you connect one trailer, the leads to the other trailer are now "hot" and can shock/electrocute some body. Say you use a 15-20 amp "plug and socket" to connect each trailer. Normally the "socket" is the "hot" (protected from human touch) and the plug "blades" are un-powered. However, when connecting the second trailer, both the wiring from the trailer is powered, and potentially the power from the charger is powered by the first trailer. Having a pair of switches at the "combiner point" lets you keep the "2nd connection" "dead" until you connect (if using standard plugs and sockets at the trailer).

The SmartGauge website talks about how to "optimally" connect batteries so they "share charging/discharging current" when you have paralleled battery banks:

http://www.smartgauge.co.uk/batt_con.html

To be honest, your setup with separate "battery pods" makes it difficult to wire optimally... So in your case, you are just using (relatively) heavy wire between batteries to keep voltage drop between pods low.

I guess, which ever is your largest "AmpHour Pod", wire per the SmartGauge link... Wire each other "pod" like per the link... And simply run the + and - connections between each pod... There is nothing else you can do to make "and optimal" distributed battery bank wiring scheme.

I am not a fan of running multiple parallel sets of wiring (such as wiring banks in parallel then running, for example, charger connections to each pod too--Those "charger connections" now become more parallel connections). The "extra parallel wiring" are more possible shorts and poor connections waiting to happen (and more $$ copper). But then you have this parallel cabling. Say 8 AWG (just example numbers to type about) from charger and 4/0 for battery main connections. If you have a poor 4/0 connection, it would now force your 3,000 Watt inverter to draw its current through the remaining 8 AWG connections and could overheat those remaining "good" small AWG cables. This is why paralleling current connections (i.e., 2x 1/0 in parallel vs 1x 4/0 is usually not allowed or a good idea).

And each small AWG parallel connection back to the charge controller should have its own fuse/breaker (protect the 8 AWG cable against short circuits)... More cost and complexity and more to go wrong.

You have a relatively "complex" wiring scheme for your bus... You have to be very careful that you don't setup trip points (such as "live connections" at the "2nd trailer" or multiple parallel connections without fuses/breakers.

Glad to hear your email notifications are working... You can go to your profile and edit what kinds of notifications you want to receive here:

https://forum.solar-electric.com/profile/preferences/

Take care,
-Bill

If the "left of drawing" 3+5 batteries are next to each other (4" apart between the two groups?)... I would wire them up as #2 in the SmartGauge drawing. Very simple wiring is my goal. #2 gives you simple point to point cables that are the "right length" and one (or two) long cables to connect to the "battery common buses".

#3 is good, but I fear that you will end up with a large clump of 4' cables (long enough cables to reach the farthest batteries, and clumped with tangled cables that are "too long" to reach the nearby batteries leaving you with a rats nest (the idea being that all battery cable sets are the same length, same resistance, balanced current flow).

The two batteries in the next to the charger--Wire them how you like and combine their +/- buses to the cable running to the 3+5 bank.

I could tell you to add fuses/breakers at various points (like on the 3+5 bus + bus bar and another breaker on the 2 battery bus bar--But I am not sure what that buys you for safety...

The plan is for every + cable that "leaves" the + battery bus should have its own breaker/fuse to protect that cable from over current (if shorted). If you use breakers, that also gives you a handy on/off switch to isolate battery banks for service...

-Bill

Hi Bill,

Just to be clear--That is 4 Feet apart (4')... 4" is 4 inches...

Even 4 feet apart--I would probably still go with #2 wiring diagram. Trying to do #3 in a tight battery box(es) is probably not worth trying to jam everything into a cramped space. Whether you treat the 3+5 groups as one bank or as two separate banks connected together--That is up to you. Wiring them up as one bank (via #2) is "better" especially if all your loads/charging sources are connected to the one 3+5 bus.

If you have distributed major loads/charger connections are mixed (some in 3 battery areas and others are in 5 bank area, then I would keep the wiring "simple" and not run "extra" load/charging wiring trying to make a single bus location. (if that makes sense).

The last 2 battery set--So far away that it is practicable to add it via #2 diagram.

Just monitor your battery bank voltages (during charging/discharging) and make sure you don't have large voltage drops/differences during charging and discharging.

Regarding the 7,000 Watt genset...You might want to look at a second smaller 2,000 Watt or so inverter-generator... Especially if you keep your loads "smaller", especially during winter/poor sun. 7 kWatt gensets with light loading (i.e., genset loads closer to 1,000-2,000 Watts) are usually horrible inefficient. You do not get "fuel" efficient with standard type gensets until you are at or over 50% of rated load (around 3,500 Watts for your genset).

Inverter-generators tend to be relatively fuel efficient down to 25% of rated power (i.e., even down towards 500 Watts of loading).

A 2 kWatt ivnerter generator will run on 1 gallon of fuel for something like 4-9 hours.

A 7kWatt Onan:

https://norwall.com/products/cummins-onan-qg-7-0-gasoline-rv-generator-7.0hgjab-900

Runs at 0.7 gallons per hour (if I read the spec's correctly) or ( 1/0.7gph= ) ~1.4 hours per gallon @50% load...

Or something like (8 hours / 1.4 hours) = 5.7 times more fuel for the larger genset... IF you are running smaller load (i.e., ~1,750 Watts genset loads).

If, on average, you have larger loads (i.e. >=3,500 Watts), then you need the larger genset.

But if you looking for longer genset run times... Say 12 hours per day (to keep fridge/freezers cold), then:

• 12 hours per day / 8 hours per gallon = 1.5 Gallons per 12 hours per day (small genset, small loads)
• 12 hours per day / 1.4 hours per gallon = 8.6 Gallons per 12 hours per day (big genset, small or larger loads)

2x 5 gallon Gas Cans will last the small genset (and smaller loads) will run a 2kW inverter-generator over 6 days. The larger genst will run for just over 1 day...

For longer term outages (a week or two)--That is a huge difference in the amount of fuel you need to store:

• 14 days * 1.5 gpd = 21 gallons of fuel for two week outage (2 kWatt inverter-generator)
• 14 days * 8.6 gpd = 120 gallons of fuel for two week outage (7 kWatt genset)

You do have fuel tanks already in the bus--Which can be great for fuel storage (not sure if diesel+gasoline tanks)... But you also run into the issue of fuel storage... Gasoline even with preservative should probably be "recycled" every 1 year. Diesel with preservative can last longer--But you do have algae issues if you get water/condensation in the tank.

Propane is a great fuel for storage--And if you already have propane tank(s) at your farm--Then a propane powered genset is a nice mix (get a propane or Propane+Gasoline) capable 3 kWatt inverter-generator (not many propane small inverter-generators available if you want a smaller 2kWatt inverter-genset).

If you are not familiar with inverter-generators... They are a standard generator driving an AC inverter... This allows the generator to throttle back to lower RPM during light loading--Saving lots of fuel. This is "true" for gasoline/propane/natural gas engines.

Or look at smaller diesel gensets--They are much more fuel efficient at lower loads (diesel engines are more fuel efficient themselves). But there is the higher cost of diesel engines (and still issues with long term fuel storage). If you use diesel around the farm anyway--Not a bad option.

Adding more solar panels is always a good place to start--Anything you can do to reduce fuel usage (during outages, winter) is going to be important.

Gensets are frequently a better cost effective solution for random short outages (a couple days every few years)--But the fuel issues are not trivial.

-Bill

Battery compartments close together--That is better.

-Bill

How much current do you plan to draw?

The "issue" with #2 (SmartGauge) laddering of parallel batteries... Say you want to draw 20 amps from each battery max. The first battery in the string will supply 20 amps, the next another 20 amps, and the next (20+20+20...) until you have the last battery connection supplying (for example) 10 batteries * 20 amps each = 200 Amps.

In the ladder scheme, you are drawing current from "kitty cornered" connections. So the current is adding kitty corner too. The The interconnects are adding current so that your increasing current on the positive connectors and increasing AWG is the "opposite" of the decreasing negative connections.

http://www.smartgauge.co.uk/batt_con.html


or:
                              -Bus common
20 amps                 80 amps
40 amps                 60 amps
60 amps                 40 amps
80 amps                 20 amps
+Bus Common

You could size each cable according to its "planned" current loading... Or just size everything the same for the maximum (80 amps in this example)....

Sizing the interconnects for Max Current--Then you would have a fuse/breaker at the final "bus connection" pont. And anywhere there is (possible) short circuit, then all "heavy AWG" cables are protected by the same (100 Amp or whatever) breaker.

Costs a lot of copper (heavy AWG interconnects)--However it is "safe(er)" from that I can see.

In your case, if you plan on using a 3,000 Watt AC inverter at full power, then the minimum wiring/fuse sizing would be:

• 3,000 Watts * 1/0.85 AC inverter eff * 1/10.5 volts battery cutoff * 1.25 NEC breaker/wiring derating = 420 Amps Wring+Breaker rating

That is the problem with Wattage 12 VDC inverters... Need really heavy cable to support high current and low voltage drop for 12 VDC...

Sometimes you can find local shops (battery sellers, possibly welding supply stores) that can help you with cable ends/crimping/etc...

-Bill

We can review your final configuration again (solar panel Imp/Vmp, which solar charger you plan on using)... But from a quick review of an earlier post of mine, you should be wiring up 4 panels in series... Then connecting those two strings (trailers) in paralle.

I suggested that each trailer have its own run of 100 Feet of 10 AWG cable connected in parallel at the MPPT solar charge controller's MPPT input. That was to reduce voltage drop. If you combined the two parallel strings "at the trailers", then you would have a goodly amount of voltage drop on the single run of 10 AWG cable pairs for 100 feet... The system would still work--Just more loses.

Your drawing above has the two trailers connected in effectively a short circuit with each other. Like connecting two 12 volt batteries + to - and - to plus...

What you should be doing is connecting trailer A + to trailer B+, and trailer A - to trailer B- in parallel. Just like connecting two 100 AH 12 volt batteries in parallel for a 200 AH @ 12 volt battery bank.

You could electrically connect the two trailers in parallel  for 8 series panels.. But that is too high of voltage for your MPPT controller (Voc-array-cold) and would ruin it.

I may be wrong--You have had a lot of questions... If you wish, let me know which MPPT solar charge controller you want to do for the solar array and what Vmp/Imp solar panel ratings are to conform.

One other thing to remember (if I did not type this warning before)... Always make the +/- connections from MPPT controller to the battery bank first, then make the solar array +/- second.

And disconnect the solar array to the MPPT charge controller first, then the battery bank last.

If you connect the solar array (under sunlight) first, then the battery bank second--You can ruin the solar charge controller, and/or possible "confuse" the charge controller during boot. The controllers are designed to boot from the battery bank first (start the microprocessor) and for the controller to measure battery bank voltage to auto configure for 12/24/48 volt battery bus. If powered by the solar array first, the controller will not boot correctly (no battery bank voltage) and could damage itself with solar power and no battery bank connection.

-Bill

What brand/model of MPPT solar charge controller did you use? Is it only connected to the "trailer" arrays or are you sharing one cotnroller with an existing array?

What is the Voc/Isc/Vmp/Imp of your trailer panels?

I know I can go look up our past posts... But I need to make sure that I know what you are using now--For sure. Also it keeps our discussion "clean" without all of the back and forth on earlier posts.

We need to get this correct. I believe that 8 series panels is too high of voltage for your charge controller's Vpanel input voltage.

And "12 volt" solar panels are not really "12 volts"... They have a Vmp and Voc which are higher voltages.

These not "12 volt panels" for example... They are (guessing) Vmp~18 volts (or 17.5 votls) panels (standard test conditions). And guess that Voc~21.5 volts (Standard test conditions):

• 4 * 18 volts Vmp (in series) = 72 Volts Vmp array (for one trailer).... 
• 4 * 21.5 volts Vmp (in series) = 86 volts Vmp-array (for one trailer)

If you put 8 panels in series, that would make for Voc-array-std = (21.5*8=172) 172 volts Vmp-array-std -- Which is (as I recall) much higher voltage than your proposed MPPT charge controller is rated for (typically 100-150 Volts Vpanel-max for most mid-range controllers).

That is why we broke the 8 panels into 4 series * 2 parallel cables to both work with your proposed charge controller and the mechanical mounting of 4 panels per trailer.

Also, referring to my post #4 above, if you use a single pair of 10 AWG cables for the 100 foot run from trailers to charge controller, you will lose around:
6.42% of your trailer(s) array(s) output power using just one pair of 10 AWG cables... If you use two pair, you would lose 1/2 that amount of power...

-Bill

I was afraid you were going to ask how to plug in the trailers to your solar wiring run back to the controller... This is a messy situation. Because you are paralleling two trailers together you have a shock hazard where one trailer plugged in and powers the wiring, and the second trailer now has 80 VDC on both its side of the connection (typically a socket protected against shock) and the typical bladed plug from the wiring back to the controller...

You could use MC4 connectors to attach the solar panels on trailers to your cable run back to the solar charge controller:

https://www.solar-electric.com/learning-center/how-to-use-mc4-connectors-cables.html/

The issue I worry about is that 1) MC4 connectors do not have a high mating life... Something like 50-100x (?) as I recall. They really are designed to be installed "once" with the panels and left connected.

Another issue--Make sure you have the solar power shut off to (switch breaker before charge controller) or connect/disconnect "at night" (or cover the solar panels with tarps). The MC4 connectors will be damaged if unplugged under load (they will arc and damage the contact surfaces).

The nice thing about MC4 connectors (you are supposed to use tools to unlock the connectors) is that they are relatively shielded against shock--No exposed/energize metal for somebody to touch (roughly 20 volts * 4 panels = 80 VDC which is "dangerous" per code). One could argue that 50 cycle "life" of mating/unmating--That is 50 years of hauling trailers once a year and returning back to shed when done for season... Longer than "I" need to worry about....

You can use simple 120/240 VAC twist lock connectors but you have the choice to install the "socket end" on the solar array (no exposed blades to shock somebody)--But run into the issue that with two trailers in parallel--If you have one trailer connected, then the parallel bladed connector is now energized from the first trailer while the the female side is energized by the second trailer (I hope this all makes sense). It is like making a "suicide" plug for AC power... For example attaching two bladed plugs on an extension cord--Can be used to connect power from from a genset to the home wiring (bladed plug into genset, and bladed plug into home wiring with the main breaker turned off).

An "interesting" solution are Anderson Powerpole connectors. they are available in multiple colors (red/black/green/etc.) and are "stackable"--You can make (for example) a three cable plug (red+black+green) polarized and they are "shrouded connectors" so they don't have exposed "blades".

https://www.andersonpower.com/us/en/shop/wire-to-wire.html?amperage_range=13&color=108,110,107&stackable=57&wire_size=41

Or you could use a pair of Twist (Turn?) Lock connectors from the hardware store... Attach the female sockets to the trailers and the male bladed plugs to the fixed run back to the charge controller/battery shed. Just choose a twist lock that you don't have on your place for 120/240 power cords/tools at your place (twist locks are defined for voltage/current/etc. so they cannot be plugged into to the "wrong" circuit).

What ever you do, installing the plugs/sockets in a weather proof enclosure at the trailers (i.e., buried cable from controller to enclosure(s) next to trailer(s) so you can lockup/protect against weather and anyone (kids, etc.) from unplugging cables and getting shocked. And sockets (vs bladed connectors) at the trailers makes most sense (so trailers don't shock anyone).

Technically, you need to ground the solar panel frames and trailers to protect against lightning strikes (if common for you) and prevent electrocution too (i.e., tie ground to local ground rod, even run a ground wire connection from trailers to solar shed. This stuff is messy (trailers, over 60 Volts of power, etc.)--You need to be careful/safe.

I am not there, and all of this gets a bit out of code--So I cannot tell you what to do (there are shielded connectors but they get horribly expensive). Your choices, your installation. I can talk about options, but it is very difficult (nearly impossible) to make your installation "meet code". I (and the forum) are not responsible for your choices/installation. (Yea, the disclaimers).

The question about cable runs from trailers back to the shed... A single pair or 10 AWG cables would work with relatively high losses due to resistance (6.42% losses).

If you run a pair of 10 AWG to each trailer (two pairs from shed), then you would be down to 3.21% losses... and "Y" connect at the the MPPT charge controller.

Or you could run a single pair of 6 AWG from shed to weather resistant box, then "Y" cables to each trailer in 10 AWG) and have less than 3.21% Loss (two pair of 10 AWG cables are the same resistance as one pair of 7 AWG cable--But "odd" size AWG cable is usually custom ordered).

The question of 4 panels in series vs 8 panels in series... For what you want to do, 4 series * 2 parallel for the two trailers is "optimum" for your needs. 8x series panels are too high of voltage for your 150 Volt MPPT solar charge controller.

-Bill

Regarding 48 volt vs XX volts on drawing: Roughly, the voltage from each trailer 4s * 1p array will range from zero VDC (dark) to 58 VDC (Vmp-array-hot) to 115 VDC (Voc-array-arctic temperatures) (just worst case rules of thumb, can calculate the more exact numbers for your location) based on solar panels.

The voltage for the MPPT controller's Vpanel-input will range from zero VDC (no sun) to 15 VDC (for 12 volt battery bank and 1x of your panels) to 150 VDC (Vpanel-max)...

Solar panels are not "batteries" (voltage based source i.e., a 12 volt battery runs from 10.5 VDC Dead to 15-16 VDC charging).

They are current sources (i.e., output ~5 amps from Zero to Vmp in full sun--just to pick random numbers). What meaning do you want the drawing voltage labeling to convey?

Using 48 VDC is a shorthand that does not help "me" as an "engineer" properly design/configure your system. For UL/NRTL/etc... There is a "critical voltage" of 60 Volts--At/above which is considered a hazardous voltage which must be behind "locked" (key or tool) door to prevent unauthorized access.

The confusion also arose because (as I understand your system/requirements) there should be 4s * 2p array(s). If you call these "12 volt panels" then 4x12=48 volt arrays. And they are supposed to be connected in parallel for 48 volts and 2x the per array current.

When you marked 96 volts, that was calling for series connecting your two trailers or 8x "12 volt panels in series (8s * 1p) which would exceed your controllers 150 VDC max panel input voltage (8 panels * 20.6 volts Voc-std = 164 VDC Voc-std --- standard test conditions of 1,000 w/sqmeter sun @ 77F/25C panel/cell temperatures--Remembering that Voc-panel rises as temperatures fall).

If you wanted to call these 48 volt trailers connected IN PARALLEL to a 48 VDC bus back to the charge controller @ 9.72 amps per trailer--That is fine.

If you wanted to call them (4s * 18 volts Vmp) 72 VDC Vmp-array-std cables--That is fine too... Or 15-150 VDC based on charge controller requirements---That also "works".

Again, the "big flag" for me was two "48 volt trailers" connected IN SERIES producing "96 VDC" solar bus to MPPT controller. That was indicating a "wiring error" (or a misunderstanding) on what the Trailer A + Trailer B wiring was supposed to be (parallel as designed, or series which is incorrect).

Lots of words when this is really simple... For example, if you have 2x 12 volt batteries. Connecting in parallel you have a 12 volt bus with 2x the AH rating. If you connect the two batteries in series, you have 2x the voltage or 24 volts @ AH rating. That was my original concern (parallel vs series connections of trailers).

Regarding connectors: Any connections should be inside a weather proof box... Few "plugs" are weather/UV resistant (long term) and you (especially in this case because of the parallel power sources--the two solar trailers) would expose to anyone the ability to unplug and electrocute themselves.

Here is an example of industrial weather resistant connectors:

https://www.leviton.com/en/docs/Temporary_Power_Line_Card_-_Q-741G.pdf
https://www.leviton.com/en/solutions/industries/temporary-power

Vs getting a NEMA outdoor enclosure and housing your plugs inside the secure box(es):

https://www.amazon.com/nema-enclosure/s?k=nema+enclosure

-Bill

Yes, the parallel connection of the drawing is correct.

The other question is how are you going to do the 100 feet of cable... 10 AWG, one pair or two pair, one pair of 6 AWG or what?

-Bill