Rigging grid tied system for power when grid goes down

[Ampster]

Did you watch that video?

No I did not watch the video. I have a solution that works for me but is too expensive for you. I can't think of a better solution except for you to do the research and find one that works. So far no one has come up with one that works with your voltages.

 

[codfish]

Since you are talking about a manual switch over, why not consider putting the switch(s) in a different place in the wiring?
You suggested at the feed into your existing grid tie, but the volts would be too high for the Growatt. If you instead spliced into the wiring in the middle of your strings, you could have switches that either left them in series (existing voltage) or brought out two pairs of wires at 1/2 the voltage that could be parallel'd into to the Growatt and also disconnect the input into existing inverter. This would require careful configuration of mutually exclusive DC switches to switch between the two configurations, and quite a bit more wire, but you'd have 1/2 the volts and twice the DC amps.

 

[ed6269]

Since you are talking about a manual switch over, why not consider putting the switch(s) in a different place in the wiring?
You suggested at the feed into your existing grid tie, but the volts would be too high for the Growatt. If you instead spliced into the wiring in the middle of your strings, you could have switches that either left them in series (existing voltage) or brought out two pairs of wires at 1/2 the voltage that could be parallel'd into to the Growatt and also disconnect the input into existing inverter. This would require careful configuration of mutually exclusive DC switches to switch between the two configurations, and quite a bit more wire, but you'd have 1/2 the volts and twice the DC amps.

That's genius

 

[Mendo Home Power]

Hello everyone
I know it is not recommended but hear me out.
My system is a 11 year old grid tied set up that does not have any rapid shutdown capabilities so I was thinking that if I added a blue sea A B switch before the solar panel disconnect to divert the solar panel output to a separate all in one off grid unit (say something like the growatt SPF 300TL LVMES that Will recently reviewed) I could safely get power out of my panels when the grid goes down.
Unfortunately my panels put out too much voltage (260 volts) so that growatt would not work for me. If anyone has a suggestion for a off grid all in one unit that could do 300 volts or more I would like to hear about it.
I would like to hear any thoughts or warnings on this ,what do you think?

Go with the Growatt 5kw 240v unit and a step down transformer for 120v https://www.ebay.com/itm/234005102556?hash=item367bca7fdc:g:dVsAAOSwxr5gmrl6 It can handle 450v from the PV and you can power 240v items. An auto transfer switch might also be useful so that when the grid goes down and you aren't home your necessities such as refrigeration keep running.

 

[jeremy_nash]

The lvx6048 should be arriving late July, and looks to be exactly what you are looking for, and can even do grid tie, with a 450v pv input!

LVX6048 – Watts247 Wholesale

watts247.com

 

[ed6269]

Go with the Growatt 5kw 240v unit and a step down transformer for 120v https://www.ebay.com/itm/234005102556?hash=item367bca7fdc:g:dVsAAOSwxr5gmrl6 It can handle 450v from the PV and you can power 240v items. An auto transfer switch might also be useful so that when the grid goes down and you aren't home your necessities such as refrigeration keep running.

Hey there
Thanks for this reply after looking into this unit I think it will work perfectly for what I want.
Thank you for your input

 

[Bri from IA]

Plus 1 on the Sol-Ark 12k system. Grid tie with battery backup UL listed and 500VDC max PV input. Need a 48V battery to run off-grid to handle starting surges for motors (fridge's and such). I used 4 lead acid deep cycle marines for a time prior to my LFP's ariving.

 

[Sanwizard]

I thought about removing some panels to drop the voltage down, I am so close now , but I don't really know how much below the 250 max I should be. My grid tied until has a max DC input is 300 volts.
If I just need to be a shade under the 250 I think just dropping 1 panel might do it but any more than that and I would hate to do it.
That growatt unit is only 750.00 and doesn't require batteries to work so that seems like a pretty cheap option though I would still put some sort of cheap battery setup to stabilize the power.

LV6548 has two 250V inputs, is 6.5KW, and costs around $1300.