2. Installation and ConnectionExpress5800/R120h-1E User’s Guide 129Chapter 2 PreparationsConnecting DC power cable and DC power supply2.1.6Important To prevent injuries due to electric shock or high voltage, observe thefollowing precautions.● Installation of this equipment should be performed by a trainedspecialist that is defined in NEC and IEC 60950-1 Second edition "Thestandard for Safety of Information Technology Equipment."● Connect the equipment to the secondary circuit power supply that isproperly grounded. The secondary circuit does not have directconnection with the primary circuit, and gains power from atransformer, converter, or equivalent isolation device.● The overcurrent protection of the branch circuit should be 27 A.Important When installing the DC power supply unit, the ground wire must beconnected before connecting the positive or negative electrode lead.Important Turn off the power supply before performing the power supply installationprocedure or maintenance.Note The grounded conductor of the DC supply circuit and the ground conductor areconnected each other in the server unit. For details, refer to the document includedin the power supply.Note If the grounded conductor of the DC supply circuit and the ground conductor areDC-connected on the server device, the following conditions must be met.● This device must be connected directly to the grounded electrode conductorof the DC supply system, or to the bonding jumper from the bar or the bus ofthe ground terminal of the connection destination.● This device must be installed in other devices which the grounded conductorsof the same DC supply circuit and the ground conductors are connected to,and in the same adjacent area as the DC system ground point (such as anadjacent cabinet). The DC system must be grounded elsewhere.● The DC source must be installed in the same building where the equipmentinstalled.● The switches or power-off devices should not be located on the groundedcircuit conductor between the DC source and the connection point of theground electrode conductor.For connecting the DC power cable to DC power supply, follow the procedure below.1. Cut the DC power cord at least 150 cm (59.06 in.) in length.2. If ring tongs are required for the power supply, use a crimping tool to attach the ring tongue to the powercord wire.Important The ring terminal must conform to UL certified 12 gauge.
