Tait International Limited TBCH1A Manuale Utente

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TB9400 Installation and Operation Manual
Replacing Modules
109
© Tait Limited April 2014
8.5
Replacing a Power Management Unit
Notice You must disconnect the AC and DC power cables before 
removing the PMU from the subrack.
Removal
1.
If you have not already done so, carry out the instructions in 
2.
At the front of the PMU, unplug and remove the output power 
cable
b
 to the subrack interconnect board.   Also unplug and remove 
the system control bus cable 
c
.
3.
Unplug the output power cable to the PA 
d
 and move it to one side.
4.
Loosen the screws securing the retaining clamps 
e
 and rotate the 
clamps through 90° to clear the module.
5.
Slide the PMU out of the subrack, taking care not to damage any of 
the cables.
Refitting
1.
Slide the replacement PMU into the subrack and secure it with the 
retaining clamps.
2.
Reconnect all the front and rear panel cables previously 
disconnected. Connect the DC power cables on the rear panel as 
shown in 
. Tighten the screws to a torque of 
18–20lbf·in (2–2.25N·m). Ensure the front panel cables are 
positioned correctly, and retained where required by the cable 
retaining clips in the top of the subrack (refer to 
“Appendix B – 
Inter-Module Connections” on page 117
).
3.
Carry out the instructions in 
.
100W base station
(obscured)
50W base station
b
c
d
d
e
e
e
(obscured)
e