AT&T 3.0 Telephone User Manual


 
Installing the Power Supply
NOTE:
It is not necessary to install ring generators in a new system with new012
(apparatus code 517G13 or later letter) modules or new 008 (apparatus
code 5171328 or later letter). If you are upgrading or using older modules,
see Maintenance and Troubleshooting.
Turning Off the Power
1 Turn off each power supply.
2 Disconnect all power cords and auxiliary units.
Installing a Copper Shield
1
2
3
4
5
The added power supply in each expansion carrier can cause excessive
noise in the module occupying the next slot, To eliminate this noise, a copper
foil shield is installed over the power supply. These shields and their labels
are packaged in the power unit shielding kit included with the expansion
carrier.
To install a copper shield, follow the steps below. Refer to Figure 2-6
throughout the procedure.
Make sure all power is off.
Place the power supply on a flat surface with the right side up (as viewed
from the front edge).
Wipe the module free of any dust or dirt.
Peel the backing paper from the smaller copper-foil shield to expose the
adhesive.
Check the positioning of the foil shields before sticking them to the side of the
module. Once in place, the foil is difficult to remove.
Position the foil on the upper part of the module and work out any air
bubbles as you press the foil firmly in place.
2-20 Installing the Control Unit