3Com 3C10220 Guidelines for Network Configuration, Sample topologies are shown in and Figure

Guidelines for Network Configuration 15

DC Power Socket The EPS has a 12-pin DC power socket for use only with an optional –24 VDC uninterruptible power supply (UPS). See the documentation that comes with your UPS.

The EPS normally draws power from its internal power supplies. If an external DC supply is connected, an electronic circuit in the EPS draws power from either the internal or external supply to ensure steady power delivery to the devices attached to the EPS output ports.

AC Power Socket The EPS adjusts to any supply voltage from 90 through 240V AC.

Guidelines for Network Configuration

Design your network with these guidelines in mind:

■In a typical application, the maximum UTP cable length is 100 m (328 ft.) using Category 5 cable (from the main switch or hub to the far-end NIC device).

■3Com recommends that you use a short UTP cable of 1 to 2 m (6 to 7 ft.) from the switch or hub to the EPS and a longer UTP cable of 1 to 90 m (3 to 300 ft.) from the EPS to the powered device such as the NBX Business Telephone or a 3Com wireless access point.

Sample topologies are shown in Figure 4 and Figure 5.