The cabinet must meet minimum size requirements. Airflow must be in accordance with the Electronic Industries Alliance (EIA) standard.Ensure that there is a minimum of 5 inches (12.7 cm) between the intake and exhaust vents and the cabinet wall.Rack mountingWhen you prepare your equipment rack, ensure that the rack is grounded.Ground the equipment rack to the same ground point the power service in your area uses. The ground path must be permanent.Switch groundDell EMC recommends grounding your switch. Use the S4200-ON Series switch in a CBN.Connect the grounding cables as described in S4200–ON Series Installation.Fans and airflowThe S4200-ON Series (S4248FB-ON and S4248FBL-ON) switch fans support two airflow options: normal and reverse.Fan combinationsInstallation of the fans is done as part of the factory install based on stock keeping unit (SKU) type. The S4200-ON Series has SKUs thatsupport the following configurations:• AC or DC PSU with fan airflow from the I/O to the PSU—the red indicator is the normal airflow.• AC or DC PSU with fan airflow from the PSU to the I/O—the blue indicator is the reverse airflow.Be sure to order the fans suitable to support your site’s ventilation. Use a single type of airflow fan in your switch. Do not mix reverse andnormal airflows in a single S4200-ON Series switch.For proper ventilation, position the switch in an equipment rack (or cabinet) with a minimum of 5 inches (12.7 cm) of clearance around theexhaust vents. When you install two S4200-ON Series switches near each other, to permit proper airflow, position the two switches atleast 5 inches (12.7 cm) apart. The fan speed varies based on internal temperature monitoring. The S4200-ON Series never intentionallyturns off the fans.For more information, see Fans.PowerUse the appropriate power cord with the S4200-ON Series (S4248FB-ON and S4248FBL-ON) when connecting the switch to the powersource. An AC power cord is included with each PSU.When installing AC or DC switches, follow the requirements of the National Electrical Code ANSI/NFPA 70, where applicable.The switch is powered-up when the power cord is connected between the switch and the power source. For more information, see PowerSupplies.CAUTION: Always disconnect the power cable before you service the power supply slots. The switch has multiple power cords.Before servicing, ensure all power cords are disconnected.CAUTION: Use the power supply cord as the main disconnect device on the AC switch. Ensure that the socket-outlet is located/installed near the equipment and is easily accessible.NOTE: Module power is software controlled. You do not see module LEDs when the switch powers up in ONIE.14 Site preparations