Non grid tie system
I have a PV disconnect switch just before the PV wires enter the MPPT.
I also have a battery disconnect just after the main fuse coming from the battery bank which isolates my batteries from the distribution center.
It is safe to turn off power to my distribution center via the battery disconnect at any time because it is considered low voltage (14 volts) BUT this won’t turn off power coming from the MPPT, that also feeds the distribution center, when the panels are producing.
It is not wise to turn off the PV disconnect while energized because of the arc danger from the much higher voltage (158 volts) except in an emergency.
The outgoing voltage, from the MPPT to the batteries via the distribution center is 14 volts
Placing a second “battery disconnect” between the MPPT and the distribution center, on the 14 volt lines, would allow isolation of the distribution center from both power sources, rendering it safe to change a fuse, rewire a circuit, etc. without causing an arc?
Would doing so damage the MPPT by allowing it to convert the PV voltage, and then blocking the path of the outgoing voltage?
If so, then except for emergency shutdown, I must either cover all the panels, or wait until dark before disconnecting the PV voltage to de-energize the distribution center?
I have a PV disconnect switch just before the PV wires enter the MPPT.
I also have a battery disconnect just after the main fuse coming from the battery bank which isolates my batteries from the distribution center.
It is safe to turn off power to my distribution center via the battery disconnect at any time because it is considered low voltage (14 volts) BUT this won’t turn off power coming from the MPPT, that also feeds the distribution center, when the panels are producing.
It is not wise to turn off the PV disconnect while energized because of the arc danger from the much higher voltage (158 volts) except in an emergency.
The outgoing voltage, from the MPPT to the batteries via the distribution center is 14 volts
Placing a second “battery disconnect” between the MPPT and the distribution center, on the 14 volt lines, would allow isolation of the distribution center from both power sources, rendering it safe to change a fuse, rewire a circuit, etc. without causing an arc?
Would doing so damage the MPPT by allowing it to convert the PV voltage, and then blocking the path of the outgoing voltage?
If so, then except for emergency shutdown, I must either cover all the panels, or wait until dark before disconnecting the PV voltage to de-energize the distribution center?