Off grid pv system wiring diagram help

Hello

I have got off grid solar system parts. This is the first time I am setting up an independent system.

Can someone please help check if the wire diagram is good to go ?
I am specially worried about the fuses, and circuit breaker, are they in the correct position?


Very many Thanks!  

Olle naut wrote:Hello

I have got off grid solar system parts. This is the first time I am setting up an independent system.

Can someone please help check if the wire diagram is good to go ?
I am specially worried about the fuses, and circuit breaker, are they in the correct position?


Very many Thanks!  

I would prefer to see the fuse on the inverter wire placed near the battery before the shut off.  There does not seem to be any glaring mistakes.
Cheers, David

when I installed my first PV system in 1996, the marine supply shop where I bought the gear had fuses for sale that cost as much as the solar panels! And the solar panels were not cheap. The panels were 120 watt and there were three of them in parallel, so nominally a little shy of 20 amps. Well, I figured, what can 20 amps really do? I mean 360 watts is not that much energy - it could've started a little fire I guess in the worst case; but it did not seem likely it could do more damage than buying that fuse. So I left it out. Panels are pretty well behaved - they don't make surges and they don't vibrate, so I don't perceive them to have a great potential for mischief. Now I have 2000 watts on the roof, but I still don't have a panel fuse or breaker - they cannot exceed the input rating of the controller, and the house is concrete. So I just can't see the value. Now if it was a wood-frame house it would be different. But I have never had even a hot connection terminal. I do keep a hatchet near the gear in case I have to mechanically sever a cable.

Then there is cable between the charge controller and the batteries - in my experience, charge controller fail open. They quit charging. If one COULD fail in charge mode, would it be able to trip a fuse? I can't see it happening.

The fuses on cables to the batteries are also fuses for current FROM the battery. If a charger or inverter failed in such a way as to make a dead short, then a fuse in those cables would be a real good thing - but again, these risks seem very low. I have never heard in the time I was on boats and socializing a lot with other PV system owners, heard of any of these fuses blowing. How about here? If you have a PV system with fuses, has one ever blown? How about breakers? Has one ever tripped? Have I been living on borrowed time?

Cade Johnson wrote:when I installed my first PV system in 1996, the marine supply shop where I bought the gear had fuses for sale that cost as much as the solar panels! And the solar panels were not cheap. The panels were 120 watt and there were three of them in parallel, so nominally a little shy of 20 amps. Well, I figured, what can 20 amps really do? I mean 360 watts is not that much energy - it could've started a little fire I guess in the worst case; but it did not seem likely it could do more damage than buying that fuse. So I left it out. Panels are pretty well behaved - they don't make surges and they don't vibrate, so I don't perceive them to have a great potential for mischief. Now I have 2000 watts on the roof, but I still don't have a panel fuse or breaker - they cannot exceed the input rating of the controller, and the house is concrete. So I just can't see the value. Now if it was a wood-frame house it would be different. But I have never had even a hot connection terminal. I do keep a hatchet near the gear in case I have to mechanically sever a cable.

Then there is cable between the charge controller and the batteries - in my experience, charge controller fail open. They quit charging. If one COULD fail in charge mode, would it be able to trip a fuse? I can't see it happening.

The fuses on cables to the batteries are also fuses for current FROM the battery. If a charger or inverter failed in such a way as to make a dead short, then a fuse in those cables would be a real good thing - but again, these risks seem very low. I have never heard in the time I was on boats and socializing a lot with other PV system owners, heard of any of these fuses blowing. How about here? If you have a PV system with fuses, has one ever blown? How about breakers? Has one ever tripped? Have I been living on borrowed time?

Honestly... Yes. Breakers and fuses are no longer expensive and it just makes sense to include them in a design. The fuse on the solar panel is in case of overload at source. Lightning can do that easily. Inverters do fuse open and do blow safety fuses. I am of course biased as I've been called to see dozens  of systems that have failed.  Electronics in charge controllers blow causing shorts which will blow the fuse saving the wires from melting. You can choose to not include the components but it is no different then driving a car without a seat belt because you've never had an accident or not installing smoke detectors because you've never had a house fire...
Cheers,  David

So we got the system to work and it's going smoothly Thank you very much for the good tips!