Hi,
It means there are two separate power supplies.
The switch can operate with a single power source or with dual power sources. When both power sources are operational, the switch draws power from the source with the higher voltage. If one of the two power sources fail, the other continues to power the switch.
In systems configured with the redundant power option, connect each of the two power supplies to separate independent power sources. If you fail to do this, your system might be susceptible to total power failure due to a fault in the external wiring or a tripped circuit breaker.
