Wiring Diagram Review
- Thread starter dgshelto
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Scout said:
Yes, we lost a lot of the back and forth conversation in this thread....so, to recap:
If you have a modest system, you can use this method. By modest, I mean 50 to 200 ah of battery, 100 to 400 watts solar and around 300 watt inverter, and normal modest loads to include some LED lighting, laptop and cellphone charging, maybe a small TV, radio, etc, and a small 12v fridge.
(emphasis added below for clarity, not screaming)
It's a bit technical to explain the electrical theory, but suffice to say that it works, and the electrons figure out which way to go when power is coming FROM the solar panels TO the controller and then TO the fuse panel and then TO the loads, or, FROM both the panels/controller AND battery, TO the fuse panel and then TO the loads.
Or, at night, power comes FROM the battery TO the fuse panel and then TO the load.
It's similar in some ways to communication equipment, where we have received signals and transmitted signals traveling over a single coaxial feedline at the same time, but going in opposite directions. Or, the old landline phones where one pair of wires carried electrical voice signals in and out at the same time. Full Duplex.
That's another topic, and not relevant here, except to say that in electronics, things can happen that don't seem possible unless you understand the basics.
Now...if you have a larger system overall, involving above say, 500+ watts solar, 1000+ watt inverter, induction, microwave, or resistance cooking, A/C and or large 120v power tools, a gaming laptop, lots of high power flood lights, large 120v powered fridge, etc...you need to run heavier cables anyway, and divide the system, using buss bars and seperate feeds to each device, to minimize voltage drops.
John61CT said:
Sorry...no.
It can be connected to the fuse panel, on modest systems, such as we typically see in vans and small trailers. Both of mine are wired this way.
It makes sense to me if you look at the fuse panel as an extension of the postive battery terminal. What confused me is using the same wires as charging input and power output.
As explained above it finds its way. That makes sense to me. It will always go from highest to lowest potential. (Maybe i said that backward).
I have a very modest system. Max fan,dometic cf 18, and 1 phone charger. So what limits it the rating of the fuse panel? Mine is 100 amp blue sea.
As explained above it finds its way. That makes sense to me. It will always go from highest to lowest potential. (Maybe i said that backward).
I have a very modest system. Max fan,dometic cf 18, and 1 phone charger. So what limits it the rating of the fuse panel? Mine is 100 amp blue sea.
John61CT said:
I probably wont use that load terminal on the charge controller. I understand its only for small loads.
What is sc?
I was referring to the wire in the posted diagram between the cc and fuse box. 2 wires actually pos. and neg.
At the level of physics, saying that electrons are traveling is at best an analogy.
A single pair of fat wires extending the terminal posts to a buss bar can seem to have current "flowing" in both directions
In reality, it "nets out" to one direction at a time, but that can switch at any instant.
Check out "Power Assist" mode on Victron's high end combi inverter+charger models.
A single pair of fat wires extending the terminal posts to a buss bar can seem to have current "flowing" in both directions
In reality, it "nets out" to one direction at a time, but that can switch at any instant.
Check out "Power Assist" mode on Victron's high end combi inverter+charger models.
Tx2, I looked at your diagram. I don't know the wire length or awg. You need a 30 amp fuse for the solar controller. Yes the controller can tie into the fuse panel. If the wires are large enough to handle the voltage drop of the extra connections. The only circuit that can not be common is the plus and neg of the panels.
Depends if the "medium" is solid or liquid.Weight said:
Ions or electrons are not actual physical entities, just tools for understanding, analogies that best fit certain theoretical frameworks.
From a wave POV it all works very differently.
In 500 years we'll look back at our current models and laugh.
John61CT said:
Oh ok....then your point is correct...yes, the controller needs to have connection to the battery (one path or another) whenever it has solar input.
I have had a few situations where there was solar input and no battery (brain farts:18 years messing with solar and stuff is bound to happen) but no smoke was released, however I would not advise testing it on any other controller.
Scout said:
Think of those battery terminals themselves. Dumb chunks of metal. But they can take in energy to the battery, or release it to the outside world, depending on what is hooked up: is a load pulling power, or is power being 'forced' back into the battery. (super simple analogy).
Then think of the far end of a six foot piece of 8 gauge wire hooked to the terminal. Same thing. Power can go in, or out, depending on what is hooked to the end of THAT wire.
Hook that wire to a fuse panel, and same thing: Power can go IN or OUT.
Now, again, power levels, amount of current, and voltage drops have to be considered. For the same reason that your typical smartphone charger uses tiny wires, but a starter cable on your van is BIG.
John61CT said:
For our simple DC circuits, this is a good way of looking at it....the 'net' effect is that the current will flow where it is needed, depending on the 'difference' in voltages. This difference can be large, several volts, or very small, a few millivolts.
But the electrons will flow generally from the side with more of them, and/or higher voltage, to the other side with less of them, or less voltage, assuming there is a completed electrical path.
Weight said:
Nope, not on mine, 15A is sufficient, because I only have 200 watts of solar input, and this is a PWM controller. The most current that can be produced by the two panels is about 12 amps or so. Normally it is much less than 10 amps.
If I were to add one or two more panels, I would change the fuse to a larger size. No plans for that at this time.
By the way, when I do need to work on the battery connections, I first disconnect the solar panels at the roof mounted MC4 connector. Yes, I know of the warnings, but this system, again, is not putting out large amperage. It is not enough to 'arc weld' the connectors.
Yes. not enough power for arc. I don't like pulling the mc4 apart, but we sure don't have to do that often. I use my combiner box with lugs and nuts. In general. I leave the panel connected and don't worry about disconnecting battery. The standard warnings are because of possible high voltage on the controller out put. Not likely with less than 500 watts.
Trebor English
Well-known member
I have a fuse box behind the driver's seat, solar charge controller 3 feet above, and a 75 amp hour group size 24 battery under the hood in the original battery location. The wire from the battery to the fuse box is 9 feet of AWG # 6, the size scrap I had on hand. The fuse box is located at a convenient location between the charge controller and the battery.
When charging the # 6 wire has 4 - 5 amps to the battery. If I have the MaxxFan on high then 3 amps from the fuse box goes to the fan and the remaining 1 or 2 amps go to the battery. Separate wires would take all input amps all the way to the battery then another wire would take it away.
My inverter, under the driver's seat, takes power from the fuse box. When the inverter is taking 6 amps from the fuse box it gets 4 - 5 from the solar charge controller and 2 - 3 amps from the battery.
When charging the # 6 wire has 4 - 5 amps to the battery. If I have the MaxxFan on high then 3 amps from the fuse box goes to the fan and the remaining 1 or 2 amps go to the battery. Separate wires would take all input amps all the way to the battery then another wire would take it away.
My inverter, under the driver's seat, takes power from the fuse box. When the inverter is taking 6 amps from the fuse box it gets 4 - 5 from the solar charge controller and 2 - 3 amps from the battery.
ratfink56
Well-known member
Just finished this thread and have seen no mention of circuit breakers. Not sure why. Seems as tho a circuit breaker would act as a fuse and a switch. What am I missing?
ratfink56
Well-known member
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highdesertranger
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most circuit breakers are not design to be a switch. I know people use them for that all the time. highdesertranger
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