User's Manual

PN 8100-40 LGCell 4.0 Installation, Operation, and Reference Manual B-5
620004-0 Rev. B
DC Power
B.8 DC Power
• DC power is supplied from the Expansion Hub to the RAUs via the Cat-5 twisted
pair cable. Power is supplied on one pair (1,2) of the cable.
• The maximum voltage on the cable is 12V, which conforms with UL requirement
of a maximum voltage of 60Vdc.
• Clause 14.3.1.1 of IEEE 802.3 requires Ethernet equipment to have an isolation of
2250Vdc. This means that accidentally plugging a Cat-5 twisted pair cable from an
Expansion Hub into an 803.2-compliant terminal will not cause any damage.
• Clause 14.3.2.1 of IEEE 802.3 specifies that a maximum peak differential voltage
of 2.8V on the twisted pair cable. With a cable impedance of 100 Ohms, this corre-
sponds to a maximum peak power of 16 dBm. The LGCell drive level is substan-
tially below this.