For solar controllers, I usually connect the battery first in power on and disconnect last, after PV in power off.
I recently assembled a setup with 2x Multiplus in parallel and wonder if there is a similar advised sequence in case I need to switch off for maintenance or change to standalone. My main concern is the output. Since its difficult to switch ON exactly at same time, one of the Multiplus will see voltage on the output prior to normal boot up.
I have bipolar MCBs both on input and output!
My Multis are almost all the time inverting, but for this maintenance and power off / power on, my instinct to minimize possibility of faults would be, for example:
1- Switch the parallel setup from inverting to GRID (I have them connected to Venus and AUX is used for this)
2-Switch OFF the slave. At this moment I suppose they will both turn OFF (never tried yet), if not, switch the Master OFF too.
3 - Switch OFF both bipolar MCBs on output of the units (they are shunted on the load side)
- Perform the operations I need with MK3 -
To Power ON, I simply do as instructed on the VE software, each multi will boot up and since the input MCB is never disconnected, they will synchronize the waveform with the grid.
Then, I can safely turn ON the output MCBs again.
Is there something I am missing? Is this correct or am I over-worried about it?
