I
NSTALLING
THE
DX-120
DX-120 Installation and Maintenance Manual
- 50 -
KSU Components (continued)
R
EPLACING
A
408M
OR
408E
Occasionally, when instructed to do so by a Vertical technical support representative, you may have to remove a
408M or 408E and replace it in the field. To do so, use the following the steps.
1) Be sure that the entire system is turned off.
2) Remove the KSU cover (four screws at each corner).
3) Install a static discharge wrist strap on your bare wrist, and adjust it for a snug fit.
CAUTION
Be sure that the strap is touching bare skin and is not isolated by clothing.
4) Connect the wrist strap cord between the wrist strap and an AC or earth ground.
5) Connect a static discharge wrist strap to a suitable earth ground.
CAUTION
Circuit boards are susceptible to damage caused by electrostatic
discharge. You must keep this in mind as you handle the circuit boards.
For additional information, see Vertical publication IMI01-005, Handling of
Electrostatically Sensitive Components.
6) Remove all circuit modules from the KSU cabinet.
NOTE
•
All modules are fastened in place using standoff hardware, therefore, be sure
to reconstruct these stand off placements when you re-install the various
modules.
•
APM4 modules must be installed using 2.5 cm (nickel) stand offs.
7) Install the replacement 408M/E using the 1.5cm (brass) standoffs removed from the original.
8) Install all other remaining modules in the order that they were removed.
• Be sure to connect them to the appropriate 408M/E connector.
9) Reconnect CO line and station cabling connections as required.
CAUTION
The FCC requires that wiring of CO lines into a KSU be separated from
wiring of station apparatus into a KSU. Therefore you must use separate
cables for wiring stations and CO lines.
10) Replace the KSU cover and secure with cover screws.
11) Restore KSU power when all wiring is complete.
Summary of Contents for comdial DX-120
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