4 pole AC disconnects

[ankithasushma99]

I was trying to see if there are any 4 pole single-phase fused AC disconnects in the market which can take in output from the inverter and an additional conductor for a subpanel?

 

[Dennis Alwon]

They do make then but what amperage.... They can be very expensive some into the 3 or 4 thousand dollars for large ones. What is the extra conductor for?