Raytech TraceTek TTDM-128, User Manual

Page: 42 / 47

H56874 4/03 www.tycothermal.com +1 (650) 474-7400 42
INVESTIGATING LEAKS AND FAULTS
If the location of a leak is not apparent, it is often useful to subdivide the
leak detection circuit. To accomplish this, it is best to have a TraceTek
Portable Test Box (PTB) or extra Sensor Interface Module, and an extra
Modular End Termination. Contact your locate TraceTek representative to
obtain these products.
To subdivide the system and isolate the problems, find a connection at a
convenient point somewhere at the center of the detection circuit. You can
then use a PTB or add an additional TTSIM to test the “back half” of the
sensing circuit (to verify circuit integrity, and to detect the presence of liquid
and determine its location). If you install an end termination on the “front
half” of the circuit (going back to the existing module), you can use that
module to check the “front half” of the sensing circuit.
If you add a new TTSIM to the leak detection network (by connecting it to
the RS-485 wiring connected to the TTDM-128), follow the Set SIM Address
instructions on page 31 then perform an Update Network command (page
32). Examine the SIM Status of the new (“front half”) and old (“back half”)
channels, and compare with the SIM Status of the former combined
sensing circuit.
You can further subdivide the circuit, and even test individual lengths of
cables. Even the most perplexing problems can usually be isolated and
resolved using this methodical approach. If you wish to remove SIMs,
remember to use the Init Network menu.
Alarm and
locating module
End termination
End termination
End termination
End termination
TTSIM
PTB