Hallo Holger,
im redbook steht dazu:

#9286 Base Enterprise Enablement
The #9286 is placed on an order of an Enterprise Edition server to enable one processor's worth of 5250 OLTP capability.
Multiple #9286s can be on the order.
Supported on Models 520 (9406 only), 550, 570, and 595
Minimum operating system level: i5/OS V5R3