eraser said:
The application is to power a farm shed , i will be using ground but have
not drawn them up yet as to make the drawing less confusing
The US NEC actually has slightly different rules for agricultural buildings
than for homes. The NEC rules still apply if you are in the US, and likely
there are other
governing bodies if you are not. It's important to follow these rules to
build a safe system. Since you
are 240Vac, you must be non-US.
I was not able to see anything seriously "wrong" with your drawing other
than the fact that grounds are not shown. It seems to indicate that you have
a general understanding of how such a system goes together conceptually.
But, you need to attach some numbers to it before it could be evaluated to
any meaningful extent.
Something that does strike me as odd is the inverter isolator switch. A
large capacity switch
( and breaker or fuse) is required between battery bank and the inverter and
these can be quite costly.
It is unclear from the drawing how your switch operates. There is no need
(and I believe it is impractical) to have a direct connection from the PV or
wind charge controllers directly to
the inverter. DC comes to the inverter from the batteries, through a
breaker/fuse through a disconnect switch. PV and Wind charge controllers
connect to the battery. There should be no direct connection between the
charge source and the inverter if that is what your drawing implies. PV and
wind charging sources are too variable to be connected directly to an
inverter.
It does seem to me that you have put a lot of effort into meters and
gauges.You might find that pre-packed components like charge controllers,
and the better inverters
include several built-in metering options that may make that part of your
design unnecessaryor redundant. Have you selected what sizes and models of
charge controller, inverter, PV panel,
and wind generator you will use? If not, spend some time doing that before
you expend a lot of
effort on "rolling your own" metering subsystems. When you do, identify them
on your drawing.Pre-packaged systems usually come with pretty complete
directions and wiring diagrams. Your effort
might be better spent in selecting what pre-packaged system components are
appropriate, and then following their recommended wiring practices.
Have you done any planning on what your expected loads will be? This
isimportant to understand if you have sufficient capacity in your batteries,
andalso if your charging system (PV and wind) can keep up with the demand of
the load. The trick is to achieve a balance between all of the major
components. Wiring it all up is pretty simple.Designing a balanced system
for a specific need is the harder part of design. (It's still not that
hard,but it does need to be addressed to be successful)
When you know the capacity of things like your battery bank, inverter, load
regulators,
PV and wind regulators, you can begin to select appropriate wire and (fuse)
or breaker sizes.You can also begin to identify which types (make model) of
inverters, charge controllers that you will use.Once you have made those
selections, you will know what metering and monitoring options are
build-in, optional, or that you have to design yourself.
Where is you AC distribution panel and breaker box, or do you plan on just
plugging AC loads
into the inverter directly? Most home type inverters (non RV) require a
grounded AC distribution
panel and breakers.
While the drawing would seem nearly conceptually complete, it is missing
many details that would
make determining if it is "correct" difficult. What is the expected
load?What is the size of the inverter, charge controllers, fuse and breaker
ratings? What part of the world are you in?
How much sun and wind to you get. How far is the wind generator and PV
panels from the battery?
You show a 24Vdc inverter, but you only have a single PV panel. Have you
found a single PV panel that puts out 24V? This also implies that each
battery is 12v. Unless they
are hulking huge batteries, two batteries is probably not going to support
much of a load. Couple CPF lights?
Without some numbers, it's next to impossible to evaluate whether it is a
practical and safe system,
or just a basic concept drawing. It may not be "wrong", but it is probably
to simplified to be useful for evaluation.
You might have a look at system design articles in homepower magazine. They
show charts of
loads, identify inverters controllers by model number and capacity, list
wire sizes, breaker types and sizes as well as showing the interconnections
between the various components.
Given that type of more complete system description, it is possible for
those with some
experience to determine how well a system might perform, and if it will be
safe to use for a given purpose.
Another approach is to look at complete pre-packages systems offered by
retailers and installers.
They typically try and offer relatively balanced systems. Look at what they
are offering in a small system and use that as a guide to what you may need.
You are off to a good start, but you have a ways to go before your cows are
watching TV.
my $.02
