Off grid inverters, can they be stacked?

[rainworm]

Is there any possibility to stack 2 pure Sine wave off grid inverters of 1000 W?
Same for modified Sine wave?
Also what items in a normal house cannot run on modified Sine wave?

[inetdog]

Is there any possibility to stack 2 pure Sine wave off grid inverters of 1000 W?
Same for modified Sine wave?
Also what items in a normal house cannot run on modified Sine wave?

Both kinds can be stacked if they are from the same manufacturer and were designed to be used with synchronization. If all you do is wire them up to the same output bus, then generally not. A grid tie inverter, on the other hand, syncs off the grid and so separate inverters can be put in parallel up to the limits of the grid connection.

Motors may not like MSW, same for some types of electronics and in particular light dimmers. Some power supplies and electronic lamp ballasts will not be happy either.
Even devices which appear to run normally may be more noisy or may suffer a reduced service life.
Some types of high power motors will be particularly vulnerable.

[rainworm]

pure

Thank you for the information. That helps a lot in knowing what to order.
So modified is not an option in a normal household.
How does one pair two pure sine wave offgrids?

[inetdog]

How does one pair two pure sine wave offgrids?

Unless they are from the same manufacturer and have a provision for synchronizing their outputs, one does not.
If the manufacturer provides that feature, the instructions will tell you how to do it.