tripcode
New Member
- Joined
- Jul 20, 2020
- Messages
- 12
Hi, like the title suggests, I have finally received all my components and am in the process of putting the pieces together. This got me thinking a bit more about the wire size that came with my inverter, and raised some general questions about the inverter as such. I hope somebody can help me clarify those grey areas in my brain.
Here is my setup:
I have some questions reg. the inverter and the wiring/fuses in general in my setup:
Inverter
I have an inverter that is rated at 1000/2000W ..i.e. it should be able to handle a surge of 2000W, that is 2000W/12 = 166.xx A? I highly doubt that, what about the inverter efficiency that keeps popping up when I read about inverters online. Where does the 80% come from I havent seen anything in my manual? This is my inverter btw: http://www.ebay.com.au/itm/231544077381, turns out in the product description page it says 90% max efficiency, if I do the maths with that, I end up with a max current of 150A (2000*.9/12).
The follow up question to this would be, how do you suggest to size the cable/fuse for this, according to the maths with an optimal surge power, I should get 166 A, thus the wire should be at least 1/0 AWG if not 2/0 ? And the fuse around 175A or even 200A? Isnt this overkill??? Of course, one can say, just size to your needs.. well.. what if I decide to treat myself with a blender or sorts knowing that my inverter could handle it.. and then realize, whoops... I only sized my cables to my 'needs'. So my goal here is really to size to the maximum power consumption that is basically possible and safe. Which with this inverter certainly wont go over 2000W.
Starter/Solar Batt / DC Charger:
Following up on sizing question, is the 80A between my DC DC charger and the starter battery not overkill as well, as my DC DC charger can draw a maximum of 50 A from a single source or 25 A each if running on alternator and PV. Thus a fuse of, lets say 60A with a cable that can handle 70A should be fine, i.e. 6awg? Or simply put, can it not be the same as I have between the DC DC and solar batteries. 4-6AWG wires and a fuse of 70 A?
Solar Panels / Current Rating:
As I am running two 250W rated at 12V nominal, 18.6 Vmp. I should get a current of maximum of 26.88ish amps from the PV source. Therefore I decided to put in a 30A fuse. But something - maybe im just overthinking - got me thinking is, can I be certain that the DC DC charger wont try to draw, lets say 500W/12v = 41A. I am pretty sure I made a mistake in my thinking, and I am kind of realizing my mistake, just as I am writing this.. i.e. I need a 30A fuse PER solar panel, and not for the whole bunch where the branch connectors are. Is this correct? So 2x30A, or 1x 30A per panel. That makes more sense.
To summarize, this is what I am planning on doing, can somebody comment on its 'correctness' and point out the flaws?
solar panels in parallel (2x250W)-> 1x30A fuse per panel, 10AWG wire from branch connector to -> DC DC charger (max current shouldnt exceed 41A)
starter batt -> 4/6 awg with a 70A fuse -> DC DC charger (max current shouldnt exceed 50A)
DC DC charger -> 4/6 awg with a 70A fuse -> solar batteries 2x 105Ah in parallel (max current shouldnt exceed 50A, because the DCDC charger wont handle more)
solar batteries -> 1 awg, with a fuse of 175A (distance from batt to inverter is less than 1m) -> inverter (max current shouldnt exceed 150A as, because 2000w * 0.85 / 12 = 141ish A)
If you have read this, thank you, regardless if you actually try to answer my questions. Of course I would highly appreciate a bit of clarification as this is my first setup and I am planning to sleep in the same place as this setup will run (campervan) therefore, trying to avoid setting anything on fire .
EDIT:
I amended my setup sketch a bit and here is the new version, please let me know if you also approve this:
Here is my setup:
I have some questions reg. the inverter and the wiring/fuses in general in my setup:
Inverter
I have an inverter that is rated at 1000/2000W ..i.e. it should be able to handle a surge of 2000W, that is 2000W/12 = 166.xx A? I
Starter/Solar Batt / DC Charger:
Following up on sizing question, is the 80A between my DC DC charger and the starter battery not overkill as well, as my DC DC charger can draw a maximum of 50 A from a single source or 25 A each if running on alternator and PV. Thus a fuse of, lets say 60A with a cable that can handle 70A should be fine, i.e. 6awg? Or simply put, can it not be the same as I have between the DC DC and solar batteries. 4-6AWG wires and a fuse of 70 A?
Solar Panels / Current Rating:
As I am running two 250W rated at 12V nominal, 18.6 Vmp. I should get a current of maximum of 26.88ish amps from the PV source. Therefore I decided to put in a 30A fuse. But something - maybe im just overthinking - got me thinking is, can I be certain that the DC DC charger wont try to draw, lets say 500W/12v = 41A. I am pretty sure I made a mistake in my thinking, and I am kind of realizing my mistake, just as I am writing this.. i.e. I need a 30A fuse PER solar panel, and not for the whole bunch where the branch connectors are. Is this correct? So 2x30A, or 1x 30A per panel. That makes more sense.
To summarize, this is what I am planning on doing, can somebody comment on its 'correctness' and point out the flaws?
solar panels in parallel (2x250W)-> 1x30A fuse per panel, 10AWG wire from branch connector to -> DC DC charger (max current shouldnt exceed 41A)
starter batt -> 4/6 awg with a 70A fuse -> DC DC charger (max current shouldnt exceed 50A)
DC DC charger -> 4/6 awg with a 70A fuse -> solar batteries 2x 105Ah in parallel (max current shouldnt exceed 50A, because the DCDC charger wont handle more)
solar batteries -> 1 awg, with a fuse of 175A (distance from batt to inverter is less than 1m) -> inverter (max current shouldnt exceed 150A as, because 2000w * 0.85 / 12 = 141ish A)
If you have read this, thank you, regardless if you actually try to answer my questions. Of course I would highly appreciate a bit of clarification as this is my first setup and I am planning to sleep in the same place as this setup will run (campervan) therefore, trying to avoid setting anything on fire .
EDIT:
I amended my setup sketch a bit and here is the new version, please let me know if you also approve this:
Last edited: