NEC 120 Answering Machine User Manual


 
AD-25182501CHAPTER 3
Page 36
Revision 1.0.1
NAP- 200-003
Sheet 18/29
Installation of Main Equipment
1.4 19-Inch Rack-Mounting Installation
1.3.1 NEC Australia can provide a rack assembly, which can be configured as follows:
(a) Up to four PIM’s at the front, and the requisite number of MDF units and/or sealed batteries at the
rear. Refer to Figure 2-6 for a typical example.
(b) Up to eight PIM’s, mounted back-to-back in one rack, for sites where the MDF and batteries are
mounted elsewhere.
1.3.2 For a customer-supplied rack installation, NEC Australia can provide the following mounting hardware:-
1.3.3 For typical rack-mounted layouts, see Figures 003-10 to 003-13. The 19”rack configurations shown herein
are based on the use of ribbon-type LT cables, which terminate on a connectorised 100-pair Krone block,
and standard 10-way disconnect modules for the MDF jumpers. For installations using an existing MDF,
standard 50-pair cables can be used, provided that the LT CHAMP connectors are the centre-loaded type.
1.3.4 The 19” Battery shelves are based on the use of 26 A-H batteries. The Manufacturer’s limitation is three
battery modules in parallel, so capacities greater than 78 A-H must be installed external to the rack.
2. Precautions
(i) Where the battery and MDF cables pass through a bulkhead, the grommet strip provided must be added to
the aperture, to protect the insulation.
(ii) The protective Earth must be extended to the Krone MDF back-mounts. Note that the MDF is isolated from
the rack, to avoid current-loops in the Earthing System. (AUSTEL Regulations apply).
(iii) Ensure that the rack and the PIM’s have reliable bonding to the Protective Earth of the AC power cord(s).
It is advisable to use Shakeproof washers on the PIM mounting bolts, to ensure metal-to-metal contact on
painted surfaces.
(iv) For PABX’s which are powered from a DC source only, a separate Protective Earth must be connected to
the rack and PIM’s.
(v) For a 4-PIM configuration, the capacity of the internal battery option equals that of the minimum external
option, so cost should be the only deciding factor as to the preferred type.
ITEM STOCK NUMBER
19” Rack Insert for PIM 4392029
19” Battery Shelf 4392032
Krone MDF 19” back-mount 4392078