NEC ElectraElite 48, System Hardware Manual

Page: 114 / 435

Electra Elite Issue 6
System Hardware Manual 4 - 3
2.3.2 Selecting a Permanent MDF Location
When selecting a permanent site for the MDF, the
technician may encounter some of the following
situations.
Space is Limited but must be used.
The available space may have one or more
environmental hazards.
The proposed location has poor lighting or lacks a
suitable ground for the KSU.
The technician that encounters these situations must
provide the best possible solution for installing the
equipment. This document cannot cover all possible
situations, precautions, and actions.
2.3.3 Selecting a Site for Installing the Telephones
When a site is selected for the installation of the
telephones, consider the following conditions to ensure
proper installation.
Ensure that the cable length and line resistance
(loop), between the KSU and the telephones,
comply with the specifications shown in
Table 2-3
Multiline Terminal Loop Resistance and Cable
Length
.
Select a place where devices that require an
external power supply can be easily connected to
an AC outlet.
2.4 Constructing the Main Distribution Frame (MDF)
The Main Distribution Frame (MDF) consists of two different
standard quick-connect terminal blocks that are mounted on a 3/4”
plywood backboard. Mounting these blocks on standoffs for ease
of access is recommended. The recommended blocks are 66B50
for termination of the MDF Cable Assembly and 66M50 for
termination of the station cables.
The Intermediate Distribution Frame (IDF) requires the 66M50
blocks only.