Solar wiring !

Like I said, that's a new one on me. None of my various small inverters have ever done that, and the Magnum is rated at 25V.
Back to the OP.. tying the solar to the larger gauge wire still won't arbitrarily cause this

SCVJeff,

Over voltage to the inverter may happen with solar causing the inverter to fault.

Both BFL13 and myself have experienced it in person.

If there is a disconnect switch between the battery bank and the inverter, then the solar controller may be damaged.

Shadow Catcher wrote:
There are times however when some solar controllers exceed the input voltage of the inverter, i.e. when they go into boost and for a few equalize mode.

Guss I'm living under a rock. I've never ever seen or heard an inverter fail to light because a solar charger over voltaged the inverter input.

That's still not germane to the OP's question

There are times however when some solar controllers exceed the input voltage of the inverter, i.e. when they go into boost and for a few equalize mode.

pianotuna wrote:
One small fly in the ointment. If the solar goes above the cut out voltage on the inverter you won't be too happy for the inverter to be cycling on and off. The work around is to have a switch on the input side of the solar so you can turn it off to prevent over voltage.

why would it matter ? You are just typing two devices on a big buss bar. The solar doesn't care what the inverter is doing and vice versa. I can develop over 30a off the roof and never once had an inverter issue

Boon Docker wrote:

pianotuna wrote:
One small fly in the ointment. If the solar goes above the cut out voltage on the inverter you won't be too happy for the inverter to be cycling on and off. The work around is to have a switch on the input side of the solar so you can turn it off to prevent over voltage.

Would the inverter not do the same thing if the charge controller wires were connected directly to the battery?

Yes,....that statement makes no sense at all. The charge controller does just that, it regulates the panel hi voltage down to acceptable battery voltage.

Put another way, it makes no difference which end of the cables feeding the inverter you connect the controller to.

The inverter will not run if the battery voltage goes above 15v (or whatever the set-point is for that model.) It doesn't matter if the solar wiring goes via the inverter.

If the solar is set at 14.8 and has temp comp, and it is cold out, it will go above 15v. To run the inverter you need to knock down that battery voltage. I don't have enough DC big amp draw things that will do that. Only inverter draw will, but the inverter won't run! Now what? BTDT.

You need to turn off the solar, which will see a drop in battery voltage to less than 15v, so now you can start the inverter, which will really knock down the voltage, and now you can re-start the solar.

Boon Docker wrote:

pianotuna wrote:
One small fly in the ointment. If the solar goes above the cut out voltage on the inverter you won't be too happy for the inverter to be cycling on and off. The work around is to have a switch on the input side of the solar so you can turn it off to prevent over voltage.

Would the inverter not do the same thing if the charge controller wires were connected directly to the battery?

Hopefully he will clarify the post.

I thought that this could only happen if the inverter was on with no AC loads and the CC switched to equalized and hence higher voltage. It doesn't tank very much inverter AC load to draw significant battery amps and hence drop the battery voltage below 14.8V.

I don't allow automatic equalization but apparently it can't be disabled for some CCs or chargers

It is less of a problem when connecting at the battery bank. I did encounter it when I had flooded batteries. The solution was to switch off the panels so I could start the inverter, and then restart the solar.

Inverters do have parasitic draws even when turned off. I have switches to disconnect the inverter from the DC source.

Boon Docker wrote:

pianotuna wrote:
One small fly in the ointment. If the solar goes above the cut out voltage on the inverter you won't be too happy for the inverter to be cycling on and off. The work around is to have a switch on the input side of the solar so you can turn it off to prevent over voltage.

Would the inverter not do the same thing if the charge controller wires were connected directly to the battery?

pianotuna wrote:
One small fly in the ointment. If the solar goes above the cut out voltage on the inverter you won't be too happy for the inverter to be cycling on and off. The work around is to have a switch on the input side of the solar so you can turn it off to prevent over voltage.

Would the inverter not do the same thing if the charge controller wires were connected directly to the battery?