stacking two stack able inverters from different battery banks

mahendra
mahendra Solar Expert Posts: 177 ✭✭✭
i know magnum,outback and xantrex ,inverters can be stacked to increase out or voltage,however while researching on mangnum inverters i came across that you cannot parallel/stack magnum inverters (i.e the pae series ) from different battery banks.Is there any brand of inverter or methods where two stack able inverters that can be stacked using different battery banks in each.

Comments

  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: stacking two stack able inverters from different battery banks
    mahendra wrote: »
    i know magnum,outback and xantrex ,inverters can be stacked to increase out or voltage,however while researching on mangnum inverters i came across that you cannot parallel/stack magnum inverters (i.e the pae series ) from different battery banks.Is there any brand of inverter or methods where two stack able inverters that can be stacked using different battery banks in each.
    I do not have a direct answer to your question, but one potential reason for the restriction that I can see is that the output of the stacked units would be compromised if one of the battery banks hit the low voltage cutoff (either statically or under surge load) and the other(s) did not. The communication between the stacked units may be programmed so that only the master implements the LVCO function based on its voltage measurement and it remotely controls the shutdown of the others.
    SMA SB 3000, old BP panels.
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    Re: stacking two stack able inverters from different battery banks
    inetdog wrote: »
    I do not have a direct answer to your question, but one potential reason for the restriction that I can see is that the output of the stacked units would be compromised if one of the battery banks hit the low voltage cutoff (either statically or under surge load) and the other(s) did not. The communication between the stacked units may be programmed so that only the master implements the LVCO function based on its voltage measurement and it remotely controls the shutdown of the others.

    That is a good enough answer for government work. :D

    The differences in available DC power under varying load conditions can cause changes in the individual inverter's operation which could make them "unsync" inadvertently. Under light loads it probably would not happen, but the whole reason you run stacked inverters is for heavy loads. So just when you need it most ...
  • mahendra
    mahendra Solar Expert Posts: 177 ✭✭✭
    Re: stacking two stack able inverters from different battery banks

    well the reason i had to clarify is because i am aware of the amp limits to using various nominal dc volts.So another question would be how would a 48v battery bank react to a maximum load of around 12000w ac, i.e let say three magnum 4448 pae inverters
  • inetdog
    inetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: stacking two stack able inverters from different battery banks
    mahendra wrote: »
    well the reason i had to clarify is because i am aware of the amp limits to using various nominal dc volts.So another question would be how would a 48v battery bank react to a maximum load of around 12000w ac, i.e let say three magnum 4448 pae inverters

    It all depends on the capacity of the battery bank and the size of all of the wires. 12000 watts at 48 volts will be 250 amps (times maybe 1.2 or more for inverter efficiency losses.) Can your batteries handle that? It would be a minimum size bank of either 2000AH of FLA type or 250AH of AGMs that are rated for 1C use.
    The second question, of course, is how long you need to supply this before recharging. :-)
    SMA SB 3000, old BP panels.