Noob with Classic's

[Lord_Kimbou]

Hi! I'm new here, and I have various noob questions..

I start with my Solar Installation, for now my configuration are:

2x 24v volt panel (280W)
2x Classics 200
6 cell (920ah) -> 12v

My first questions is: I'm planning to add more solar panels, and for now I'll stay on 12v.. I want to make an array with 3x3 solar panels.

The sizingTool say this:

Array Power (Wattage) ->  EXCESSIVE
Classics Required ->            2.3

2 classic together are 2.4, right?

Then... If I connect the 2 classics in follow me mode, and Pv cable is de same in two classic (I connect both with "Y cable for example") this configuration is ok??? 

For now I only ask this for start!

Thanks a lot! And sorry my bad English! 

[Vic]

Hi Lord ...   welcome to the Forum,

Each Classic needs its own separate PV array.

Please explain your planned PV array,   are there two 280 watt PV panels in parallel for each Classic?

There should not be a problem running 560 watts of panels for a Classic 200.

If you are not planning on running fairly high string voltages,   a Classic 150 will  run cooler,   and be able to supply a bit more output current than will a Classic 200.

Your English is fine!   Vic

[Lord_Kimbou]

Thanks Vic!!

Then.. This is my new Basic Schematic.. For example Array 1 (2 pv 280w serial X 2 pv 280w parallel ), and Array 2 (2 pv 280w serial X 2 pv 280w parallel)..

My second problem is "protect" the system.. I see several configurations but I don't understand what protection I'll need.. Breakers there are so many, and I'm lost here...

[Vic]

Hi Lord..,

Thank you for the nice,  clear Schematic.

We are not certain of your location,   any Codes  (regulations)   that this system will need to pass,   and how this system will be used.   But,  in the USA,   we generally do not need to have overcurrent protection it both of the PV cables  (with a couple of exceptions).

Did run Solarworld 280 Mono PVs through the String Sizing Tool,   2X2 for each Classic,   the result is Attached.   These are 60 Cell Mono PVs.    These PVs may well be similar to the ones that you are using.   Some 280 PVs are 72 Cell PVs,   and might change the String Sizer results.

From this point,  on,  there are some variable factors that could be affected by how you might expand this system in the future.

PV arrays with strings of less than three PVs (or with less than three parallel PVs) do not require a PV String COmbiner.    But,  depending on any future expansion,   that uses three or more PV  strings would need a Combiner for safety,   and convenience.

For this system at the beginning,   would suggest using the MidNite MNEPV DC breaker,   with a maximum current rating equal to the PV manufacturer's "Maximum Fuse Rating",   "Maximum Reverse Current",   or similar words.   Here is a Link for this breaker from a USA supplier,  just to give you the basic info on this breaker:
https://www.solar-electric.com/midnite-solar-mnepv-15-amps-circuit-breaker.html

These breakers can mount in a MidNite metal box.   One such box is the MidNite Big Baby Box.   There are MN Mini DC boxes,   and E-Panels,   etc,   that have room for more breakers,   etc

You really DO need a circuit breaker between the output of the Classic,   and the battery,  as you have shown on the Schematic (IIRC).   THis breaker protects the cables that they connect to.   This rating depends upon the temperature rating of the cable insulation,   the number of other cables that are together,   plus several other factors.   Especially on 12 and 24 V systems,   voltage drop in this cable is an important consideration,   so you may wish to increase the diameter of this cable just to keep the voltage drop as low as possible,  for the best battery charging control.

Am out of time,   now,   will check back later,   and others may well want to add their input.

Thanks,   Vic

[Vic]

A bit more info on MidNite boxes for breakers,   and Balance Of System parts.

A small box that will accept up to four MNEPV (DIN) breakers:
https://www.solar-electric.com/misobigbabox.html

Here is a larger box,   that includes a main circuit breaker,   that is often used to connect the battery DC voltage to an inverter:
https://www.solar-electric.com/midcdipocewi.html

For a bit larger system,   here is an example of an E-panel (there are many to choose from):
http://www.midnitesolar.com/products.php?menuItem=products&productCat_ID=2&productCatName=E-Panel Lite - For use with TraceSW, DR, RS etc.

The above are just a few items that might help you get system parts mounted,   and connected.

Your starter system should,  generally,   not require a Combiner for PV breakers (one breaker for each PV string),  but here is an example of one:
http://www.midnitesolar.com/productPhoto.php?product_ID=77&productCatName=Combiners&productCat_ID=9&sortOrder=5&act=p

The manual for your Classic  has a number of wiring diagrams,   should you need some info on interconnecting the system components.

You may know much or all of the above,   but just in case,   it could fill in some questions that you might have.

What will be the use for your initial system,   if we might ask?

FWIW,   Vic

[Lord_Kimbou]

Thanks VIC! You are the best! 

For now, the initial use is for a weekend house.. TV some hours, Fridge, water pump, perhaps some times a grinder or electric saw..

But in the future, that house will become my principal house. This is the reason why I want to do the installation right from the beginning.

Well... The first part of installation: Pv1 and Pv2, cable AWG10 to Fuses (or breakers), Combiner for 2 differents arrays (fuses or breakers inside), and one AWG6 to Classic 1 (array1), and other AWG6 from Combiner part2 to Classic 2 (array 2).. It's ok this part??

Thanks again!

[Vic]

Hi Lord_Kimbou,  thank you for the added detail of the uses of the system,  and future plans.

The cable sizes  look fine.   Just use circuit breakers (breakers will really be a better approach) that are sized for the cable current rating at 75 degrees C,  maximum.  Breakers (and fuses) are used to protect the cables from overcurrent,  which causes overheating,   and could be a fire hazard.  DC-rated breakers are inexpensive,   and can be used as a Disconnect (fuses cannot,  and when a fuse blows (opens from overcurrent),  it must be replaced),   breakers work very well,  to protect the cables.   Breakers are needed,   near the Classics,  when doing Firmware updates,   and breakers are convenient when diagnosing problems with the system (Combiner breakers will allow checking each PV string's contribution to power production,  etc).

Classics can accept battery connection cables up to #4 AWG.   For 12 volt systems,   the reduction in the voltage drop from using #4,  compared to #6 cable could be slightly better,  if those battery connections are very long.

As you know,  replacing inverters is usually expensive,  when changing from  a 12V system,  to 24 or 48V.   AND,  adding batteries to a system (to increase the voltage to 24 or 48V)  can cause some troubles,  if  the original batteries have been in service for more than a few months.   It seems that you already have the battery,   so suggesting,   beginning with a 24 or 48 V system,   is probably is not feasible.

Thanks for the update,   and please keep us informed about  your progress.   Vic