PAL-AT Operating Manual
5
1 Introduction
1.1 Theory of Operation
PAL-AT
®
uses a pulsed cable-radar technology to detect leaks. PAL-AT sends out low voltage pulses on
a cable and monitors reflections received back at the panel. PAL-AT electronically divides the cable into
short increments and measures the reflections from each increment. It stores the measured values in
memory during the reference procedure in a permanent record called the “master” map. When in monitor
mode, PAL-AT compares the current condition with the master map. Significant changes from the master,
for instance when the cable gets wet, cause PAL-AT to enter the alarm mode.
This latest generation of PAL-AT systems automatically creates a new master map after a leak event is
detected. This puts the system back on-line immediately to monitor the entire cable for leaks getting larger
or new leaks (see section 2.2).
Comparing the current condition with a baseline map enables PAL-AT to monitor a system with minor
installation inconsistencies and small amounts of wet cable. PAL-AT can accept initial field conditions that
force other systems to reduce their sensitivity or be inoperative. It also enables the system to locate
additional leaks occurring past previously detected leaks.
PAL-AT detects and locates six types of changes:
1. Leak
2. Drying
3. Short
4. Break
5. Probe Activated
6. Probe Reset
Normally PAL-AT is set to activate alarms for leaks, shorts, breaks, and probes activated but not for a
drying cable or probe reset (see section 2.9.3.2). If the system detects a break or short, it will still monitor
for leaks up to the break/short, and display the distance to the leak.
As explained above, PAL-AT accepts and monitors a system with an initial small amount of wet cable.
Normally this only occurs in secondary containment applications. To maintain the long-term integrity of
the containment and ensure the proper operation of PAL-AT, the containment should be dried before (or
shortly after) the system is put on-line. The containment should also be cleaned and dried after any future
leak is detected.
1.2 Start Up
1.2.1 Installation Instructions
All applicable manuals must be reviewed and understood prior to installing and operating the PAL-
AT system. Detailed installation instructions are provided in the PAL-AT Installation Manual. Refer to
that manual for installation for the PAL-AT panel, cables and all accessories.
Caution - Access inside the PAL-AT panel should be limited to qualified personnel. Risk of electrical
shock exists.
Power should be fed directly from a dedicated circuit breaker to PAL-AT. If the green power light on the
PAL-AT label is not lit, check the circuit breaker and the internal service power switches (see figures 1-1
and 1-2).
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