
Note how this leak event differs from the simpler leak event detailed on page 8:
• Rather than displaying the message “Leak 50 ft,” the display puts the location in square
brackets. This indicates that 50 ft is the likely location of the leak.
Case 2 - Service, then leak at same location
If a leak is detected at nearly the same location as that causing a Service Required alarm,
TTDM operates differently, as shown below.
First, there is an alarm for Service Required.
Subsequently, a full-fledged leak is detected at nearly the same location. The TTDM
responds as shown below:
Since the Service Required alarm was at the same location, it is interpreted as an early
indication of the leak. The TTDM therefore clears the service alarm, and displays the leak
location without brackets.
Leak 239 ft
17:45 28-Feb-1996
Service ReqÕd[237]
16:53 28-Feb-1996
16
17
Additional Leak
If liquid contacts the sensing cable away from the initial leak, the module will re-alarm. If
the location is distant from the last alarm, the TTDM shows a location in square brackets.
Brackets indicate that the value shown requires interpretation; when an additional leak
occurs, the value represents the “electrical center” of the leaks.
The display also prompts the user to check the Events History log in order to investigate
the sequence of events between the first leak at 50 ft, and this re-alarm event.
Service-to-Leak Alarm
Case 1 - Different locations
Although TTDM can continue to monitor when a Service Required alarm is in effect, the
accuracy of location may be impaired. TTDM indicates this by displaying the leak location
in square brackets.
Example:
If a leak contacts the sensing cable before service was performed, the display would
appear as below:
Leak [50]
15:53 14 Feb 1996
Service ReqÕd[2003]
15:53 14-Feb-1996
Leak 50 ft
Re-Alarm
[1045]
15:53 14-Feb-1996