Hitachi GR2000 - Manual (Page 394)

8.2.4.1 Input Unit (AC or DC)
1. Turn off the breaker switch on the Input Unit and unplug the power cord from
the Input Unit.
2. If the Input Unit is for AC input, detach the cover in front of the target Input Unit
as illustrated in Figure 8-6.
3. Follow the other instructions illustrated in Figure 8-6. Although the figure shows
the case of AC input, the same instructions apply to the case of DC input except
the cover mentioned above.
4. If the Input Unit is for AC input, attach the cover detached in step 2. above.