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Component Operation and Maintenance
44
The zone leak detection kit provides leak detection for a defined zone. This kit is ideal for perimeter
sensing or serpentine coverage of small areas. A simple, two-wire connection signals the alarms at a
Liebert environmental unit or at a monitoring panel. Run wires to the Liebert unit and connect them
to terminals 24 and 51, 55 or 56. The sensor utilizes Liebert's LT500Y leak detection cable. The kit is
offered with five different lengths of cable sized specifically for the type of Liebert Environmental unit
(see matrix below). Refer to matrix below for the recommended location of leak detection cable.
Remote Shutdown
A connection point is provided for customer supplied remote shutdown devices. This terminal strip is
located at the top of upflow units, and at the base of downflow units. Terminals 37 and 38 on the ter-
minal strip are jumpered when no remote shutdown device is installed.
6.2 Filters
Filters are usually the most neglected item in an environmental control system. To maintain efficient
operation, they should be checked monthly and changed as required. Because replacement intervals
vary with environmental condition and filter type, each unit is equipped with a filter clog switch. This
warns of restricted airflow through the filter compartment by activating the Change Filter alarm.
Turn power off before replacing filters.
Challenger 3000 filters are 28-1/2" by 29-1/2", either 2" or 4" thick, plus an optional 2" thick pre-filter.
The filter is replaced from the front of the unit. On upflow units, the filter is vertical, in front of the
lower compartment. Pull the filter out toward you to remove it. On downflow units, the filter is hori-
zontal, above the electrical panel. Slide the filter out toward you to remove it.
After replacing the filter(s), test the operation of the filter clog switch. Turn the adjusting screw
counter clockwise to trip the switch — this will energize the Change Filter alarm. To adjust the
switch proceed as follows: With the fan running, set the switch to energize the light with clean filters.
The unit panels must all be in place and closed to accurately find this point. Then turn the adjusting
knob one turn clockwise, or to the desired filter change point.
Table 16 Zone leak detection kit installation scenarios
Scenarios
Upflow Unit
Detection
around
entire unit
Upflow Unit
Detection on sides
and
in front of unit
Downflow Unit
Detection
around
entire unit
Downflow Unit
Detection on sides
and
in front of unit
Distance From Unit
Distance:
In back
On sides
In front
2 ft
2 ft
2 ft
No cable behind
2 ft
2 ft
1 ft
1 ft
6 ft
No cable behind
1 ft
6 ft
Unit
(footprint-
in.)
Part Number
Challenge
r
(32.5 x
32.5)
LT460-Z30 LT460-Z20 LT460-Z30 LT460-Z25
2-ft clearance
in front
2-ft clearance
in front
6-ft clearance
in front
6-ft clearance
in front