Hitachi GR2000 - Manual (Page 389)

To add or remove the power supply components to/from each model of GR2000 ot
than GR2000-2S, refer to the following subsections.
8.2.1 GR2000-4S
Turn off the power switch on the back panel, release the cable retainer and
remove the power cord.
*
Note: The power supply module of GR2000-2S cannot be added or removed by the user
because they are integral to chassis. When addition or removal of such a module
is necessitated on GR2000-2S, entrust work to trained service personnel.
*
Note: For models other than GR2000-2S, certain power supply components cannot be
added or removed by the user. For power supply components not described in
this section, entrust work to trained service personnel.
Power switch