Hitachi GR4000 Series Installation Manual page 185

Step 2
（See the section 4.5.3, which gives you the instruction related to the
attachment/detachment of the GR4000-320E (AC) power cable.）
Figure 5.4-14 Power cable removed from the power supply unit
WARNING: WHEN REPLACING A POWER SUPPLY UNIT OR INSTALLING AN
520-10-014-20X
Remove the power cable from the power supply unit targeted for replacement.
Power cable
ADDITIONAL ONE, REMOVE THE POWER CABLE FROM THE POWER SUPPLY
UNIT TO BE REPLACED. EVEN IF THE POWER SWITCH IS TURNED OFF,
ELECTRICITY IS STILL PRESENT IN THE CABLES CONNECTED TO THE
DEVICE, WHICH CAN CAUSE A FIRE OR ELECTRIC SHOCK.
GR4000 Installation Guide Version 1.00 - Preliminary
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