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diy solar

Idea for solar minisplits/pv transfer switch

jfharper

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Joined
Jul 23, 2021
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174
I'll make it quick...two solar mini splits 12K and 24K PV wired to 4 and 6 390w panels, respectively.

- Air conditioning in the summer, usually during the day as it cools off at night, so PV direct to split works well.
- Heat in the winter, usually from 2am to 10am, as it usually warms up during the day in CA, then occasionally again at 5pm on, so splits running from AC (battery bank/inverters). (I realize I would loose the ability of the splits to run hybrid from AC and DC using the below switch when the sun is up at ~7am)

What if I used a transfer switch to change the panels from, 1. direct to splits in the summer to, 2. feeding the inverters in the winter with these two items:
(or maybe something better quality when I can find it)

Max volts via voltage calculator would be 399.02 at my lowest temp...switch rated to 440v.

...anyone know of a reason why this would not work? Or am I missing something obvious...please critique. Thank you.
 
Last edited:
I'll make it quick...two solar mini splits 12K and 24K PV wired to 4 and 6 390w panels, respectively.

- Air conditioning in the summer, usually during the day as it cools off at night, so PV direct to split works well.
- Heat in the winter, usually from 2am to 10am, as it usually warms up during the day in CA, then occasionally again at 5pm on, so splits running from AC (battery bank/inverters). (I realize I would loose the ability of the splits to run hybrid from AC and DC using the below switch when the sun is up at ~7am)

What if I used a transfer switch to change the panels from, 1. direct to splits in the summer to, 2. feeding the inverters in the winter with these two items:
(or maybe something better quality when I can find it)

Max volts via voltage calculator would be 399.02 at my lowest temp...switch rated to 440v.

...anyone know of a reason why this would not work? Or am I missing something obvious...please critique. Thank you.
That switch is not rated to switch DC loads.
But as long as you only switch at night, it would work.
I can't recommend it, because mistakes happen. And fire is undesirable.
 
How bout, PV Isolator switch upstream from transfer switch, disconnect, then transfer, then reconnect...better? (after finding DC load switch) also this would be mounted at the ground mount.
 
Definitely better. But the possibility of a mistake still exists. If you forget to turn off the disconnect.
Outside is also better than inside.
 
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