2.3 Physical Installation
This unit may be installed in an EIA-standard
instrument rack or it may be mounted on a
desktop or other flat surface.
2.3.1 RACK MOUNTING
2.3.1.1 General Considerations
Observe the following guidelines when mounting this
unit in an instrument rack:
1 .
Plan the layout of the equipment in the racks before
installing equipment.
2 .
Take an inventory of all rack equipment including
hardware, brackets, blank panels, etc. Reorder any
missing parts immediately. This avoids delays in the
middle of the assembly process.
3. Provide a minimum of 1.75 inches (4.4 cm) of
empty space between each piece of equipment for
ventilation.
4 .
Use at least one blower/fan per rack. Place it in the
bottom of the rack. Thus, air is drawn in at the
bottom of the rack and vented at the top.
2.4 Wiring the Alarm Inputs
Make sure there is no power to the
before performing the following
procedure.
Alarm inputs are wired to removable 16-pin screw terminal
blocks on the rear of the
Units with 32 inputs
have one row of four of these connectors along the lower
part of the rear panel
Expanded units with 64
inputs have two rows of connectors, the upper row being
numbered from 33 64
Wiring of these
connectors may be done with the terminal block either
mounted on the unit or removed from it. Refer to Figure 3.
Each alarm input has two wires, one of which is a ground.
Note on the rear panel that each alarm number has a +
2.3.1.2 Installing the Unit in a Rack
1 .
2 .
3 .
Find the two rack-mounting brackets (Table 2, item
2) and the four flat-head screws (item 1) in the
accessory kit.
Attach one of the brackets at each end of the unit
with two screws. The long side of the bracket goes
against the side of the unit. Repeat for the other
bracket.
Slide the unit and secure it in place with four screws.
These screws must be supplied by the installer, as
different racks have different screw requirements.
2.3.2 Desk-Top Installation
In desk-top installations, the rack-mounting brackets in
the accessory kit are not used.
1 .
Turn the unit upside-down on a soft surface so that
the top of the unit is not scratched.
2 .
Find the four rubber feet in the accessory pack. Peel
the covering paper from one of the feet and attach
to the bottom of the unit near one corner. Place it
about l-inch in from the two edges. Repeat for the
other 3 rubber feet.
3 .
Turn the unit right-side up and place it where desired.
terminal and a terminal. The plus (+) terminal should
receive the active or “hot” wire from the alarm device,
and the ground wire should be connected to the adjacent
terminal marked minus
Back out the appropriate
screw on the terminal block one or two turns and insert
the wire in the opening toward the bottom of the block.
Tightening the screw clamps the wire in place. Repeat
for all alarm inputs.
All card cages have the same numbering ranges, 1 32 for
the lower connectors and 33 64 for the upper connectors.
If more than one
are cascaded together, the
additional units have higher-numbered input ranges. Tables
7 and 8 show the alarm address number versus the
number on the connector.
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X849-1297
