Specifications

Section-5 Maintenance
October 17, 2013
5‐62
Copyright©2013,HarrisBroadcast
WARNING:Disconnectprimarypower priortoservicing. 888‐2693‐004
IsolationresistorsinthePAsplitterandcombinerassembliesabsorbanyreflectedpowerresultingfromimbalances
duetomodulesbeingremovedfromservice.
Thenumberandloc
ationofPAmoduleswillvarydependingontransmittermodel.See"Figure2‐9PSandPA
ModuleLoc
ations"onpage2‐14forlocationsandnumberingofPAandPSmodels.PABPAandPSmodulescanbe
removed(orin
stalled)whilethetransmitterisoperating,butthefollowingstepsshouldbefollowed:
STEP 1
Prepareaclearpathtoalocationtoplacethemoduleonceithasbeen
removed.
STEP 2 LoosenthefastenersandopenthefrontdooronthePAB.
Caution
THE PA MODULES MAY BE HOT. USE PROTECTIVE GLOVES TO PROTECT
YOUR HANDS.
Note
PA modules in the PABs are installed in two orientations. The upper modules are installed with the cooling
fins up. The lower PAB modules are installed with the cooling fins down.
STEP 3 Grasptheleftandrightoutsidesedgesofthealuminummodulehandleand
slowlypullthemoduleoutoftherackusingmoderate,controlledpressure.
Gentlymovingthemodulefromsidetosidewhilepullingthemoduleout
mayaidinremoval.
Caution
DO NOT LET THE MODULE SWING DOWN WHEN PULLING THE MODULE
OUT OF THE RACK. THIS COULD CAUSE DAMAGE TO THE CONNECTORS
ON THE BACK OF THE MODULE.
Whenamoduleisremovedwhilethetransmitterisrunning ,twofaultswillbegenerated.Thefirstistheinterlock
whichturnsoffthepowersupplyassociatedwiththePA.Thesecondisa“BiasFault”whichtheLPUisgeneratingif
thePAcurrentsarebelowthenominalbiascurrentlev
el.Thebiasfaultisarestrikeablefault.Sincethebiasfaultwill
consistentlybetherewhenthemoduleis removed,thecontrolsystemalwaystriestorestrikethesystem.
Ifyoure
insertthemodulewithinthetimetheLPUistryingtorestrikeit(under3seconds),themodulecould
restrike.Ifthemoduleisremovedandnotre‐insertedwithintherestriketimeframe,thecontrolsystemwi ll
considertherestrikeattemptfailed.Onceamodulehasfailedarest
rikeattempt,nofaultsfromthatmodulewill
causethesystemtorestrikeuntilthesystemisresetbypressingtheONbutton.
"Figure5‐47Mod
uleRemovalandRestrikeProcess"onpage5‐63showsthetiminginvolvedinthemoduleremoval
restirkepr
ocess.