3Com 3CR17561-91-US - Switch 4500 26PORT Managed 24 10/100 2 Gbe Stackable RJ45 Getting Started Manual

Also see for Switch 4500 PWR 26-Port: Getting started Getting started Configuration guide Datasheet Getting started guide

Contents

3Com 3CR17561-91-US - Switch 4500 26PORT Managed 24 10/100 2 Gbe Stackable RJ45 Getting Started Manual Manual pdf 33 page image

Connecting a Redundant Power Supply to your Switch 4500 PWR 33The -48V DC power will take priority over the AC mains and will powerthe Switch if it is connected.Connecting theEarthing CableUse the earthing cable that accompanies your Switch if the length issuitable. Alternatively use the earthing cable specification as defined inAppendix C on page 115.The earthing cable is only required if the Switch is powered by the RPSonly.The recommended cable length should not exceed 3 metres (9.84 feet).RPS LED The RPS status LED on the front of the Switch 4500 PWR indicates thestatus of the RPS and AC supplies as shown in Table 11.Table 11 RPS LED ColorsUsing Power overEthernetThe Switch 4500 Power over Ethernet (PoE) units can supply power toany IEEE 802.3af compliant device through any of its 10/100 ports over aCategory 5 or Category 5e Ethernet cable. The same cable connects thedevice to the network.Power over Ethernet is a self-configuring protocol. When you plug a PoEcompliant device into one of the ports on the Switch, the Switch willsupply the power required to the device, providing that the total powerbudget for the Switch would not be exceeded by doing so.A PoE Switch combines the functionality of a standard Ethernet Switchwith a single power supply that can power multiple devices. Using a PoESwitch has the following advantages over an unpowered network:■ Reduced Cabling — a PoE (802.3af) compliant device which has itspower supplied over its ethernet cable does not require a separatepower supply. If, for example, the Switch is used to connect a 3Com11 Mbps Wireless LAN Access Point 8500 to the network, then only aColor StateGreen AC and RPS supply connected.Yellow AC failed or not connected. RPS supply is ok.Off There is no RPS supply connected.