• Leak Verification: If a suspected leak is indicated, verify sever-
al times by moving the sensor away from the leak area, allowing
the alarm to clear and then back to the suspected leak. If the
instrument indicates a leak three consecutive times, you have
found a leak.
• When to use LOCK-OUT: Very large leaks or areas that have
been leaking for a long time can actually form a cloud of refrig-
erant around the entire leak area. This cloud of refrigerant will
tend to mask the actual leak source making it difficult to find. The
LS790B and its LOCK-OUT mode of operation was designed
specifically for this situation. Depress the LOCK-OUT key (three
short beeps confirms that you are in LOCK-OUT mode) and start
searching the leak area. As you search the leak area, the
LS790B will automatically memorize the detected refrigerant
concentration levels, systematically searching for the highest
refrigerant concentration level. A distinct two-tone alarm will
sound when the sensor is placed in the area of the highest refrig-
erant concentration detected. This will be your leak source.
NOTE: Do not be confused! It is possible to achieve this two-
tone alarm in areas besides the actual leak source. This will
occur as the LS790B locates a higher level of refrigerant con-
centration than it had previously stored in its memory. You will
know when the unit has found the actual leak source when the
two-tone alarm only sounds at one specific area.
The LS790B A/C DETECTOR is designed to require a minimal
amount of field maintenance. Regular cleaning of the sensor hous-
ing air vents, replacement of the Ion-Pump® sensor and changing
the batteries are the only maintenance needs.
• Low Battery Condition: If the center segment of the LED dis-
play (located directly above the * symbol) illuminates when the
unit is switched on, the batteries are weak. Replace with "AA"
alkaline batteries only.
NOTE: DO NOT use rechargeable batteries.
• Changing the Ion-Pump® sensor: Eventually, the Ion-Pump®
sensor will need to be replaced. This condition is usually indi-
cated by abnormal or erratic performance when the instrument
is in the lowest sensitivity range. Install the new sensor as indi-
cated in Figure 1 (turn the unit OFF before attempting to change
the sensor). CPS
sensor at the beginning of every AC & R season and always
have a spare sensor available for replacement in the field.
• Patented Selective Housing Filter: Ensure that the sensor
housing inlet and outlet air vents are clean and free of materials
that may block the air from circulating through the Ion-Pump®
sensor. If the vents become dirty and clogged remove the hous-
ing from the probe and remove the Ion-Pump® sensor (turn the
unit OFF before removing the housing). Next, attempt to remove
any contaminants using LOW-PRESSURE shop air or by hand
ONLY. DO NOT attempt to clean this housing by any other
means. If the sensor housing remains contaminated, simply
replace it.
MAINTENANCE
recommends that you change the Ion-Pump®
®
5