Steven,

It's depends on the amount of blades in the system and load they're using.  N+1 means the mininum # of power supplies plus one extra (standby).  If a single power supply is enough juice to power your blades, then yes.  Otherwise you may need to configure non-redundant.  When you try to configure this on UCSM the system will notify you if your Power Scheme is not sufficient to provide N+1.  In this case it will just operate in non-redundant (combined) mode.

We don't normally see N+1 with anything less than 3 power supplies (as the entire system can run off 2 at full capacity).

Robert