Acer AcerAltos 21000 System Manual page 53

To remove a power supply module:
1. Detach the power cable from the electrical outlet and also from
the power supply. The power indicator light turns off.
2. Unscrew the screw knobs and carefully pull out the power supply
until it detaches from the housing.
2-28
The power supply supplied with the system
accepts input voltage of 100V~240V, 50~60Hz.
Make sure the power supply subsystem is
supplying a minimum of 860W (2 power supply
modules) to the system.
AcerAltos 21000 System Guide