Zte ZXR10 2900 Series - Page 45

Chapter4InstallationandDebugging
Figure27showsthecablingofEthernetswitchinafour-oor
buildingwiththreeunits.Where,switchAinUnit1isthecon-
vergenceswitchofthewholebuilding,andswitchesBandC
areaccessswitches.SwitchesA,B,andCarecascaded.That
is,thecascadingcableofswitchAistheuplinkcableofswitch
B,andthecascadingcableofswitchBistheuplinkcableof
switchC.Therestsubscriberlinesaredistributedinsidethe
buildingandconnectedtothesubscriberterminalsfrombot-
tomtotopinthecorridor .
FIGURE27CABLINGOFTHEETHERNETSWITCHINABUILDING
Intheabovegure,1to8standsforsubscribers.Thecascad-
ingcablereferstothecableconnectingtwoswitches.
2.Reinforcedlightningprotectionmeasuresmustbetaken
andlightningprotectionbarsmustbeaddedfortheuplink,
downlink,andcascadingEthernetportsthatareledoutdoors.
Inspecialcasewhenthecommonsubscriberlinesmustbe
distributedoutdoors,lightningprotectionbarsmustalsobe
added.Thelightningprotectioncapabilityofthelightning
protectionbarmustreach6KVoraboveandthecurrent
dischargecapabilitymustreach5KA.Thegroundingcableof
thelightningprotectionbarmusthaveadiameterof16mm
2
andalengthlessthan30cm.Itisrecommendedtousethe
opticalportastheuplinkportoftheconvergenceswitchin
thebuilding.Iftheelectricalportisused,lightningprotection
barsmustbeadded.
Figure28showsthecablingofaconvergenceswitch.Where,
theuplinkportistheopticalportandlightningprotectionbars
areaddedforthedownlinkorcascadedcables.Thelightning
barsareconnectedtotheearththroughtheshell.Therest
subscriberlinesaredistributedinsidethebuilding.
CondentialandProprietaryInformationofZTECORPORATION33