Raytech TraceTek TTDM-128, User Manual

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H56874 4/03 www.tycothermal.com +1 (650) 474-7400 36
Service Events
INTRODUCTION
A TraceTek sensing circuit consists of two electrical loops. The SIM module constantly
monitors for current passing between loops. When the system is normal, there is no
current passing between the loops.
When there is a leak on the system, the maximum current flows. If, however, a SIM
detects a lower but significant level of current flow between the loops, the TTDM will signal
a Service Alarm.
A low-level current could indicate one or more of the following:
▪
A very small leak (which may soon develop into a full leak alarm).
▪ Heavy condensation or small spills (coffee, tea, etc.) on a sensing cable for water or
aqueous solutions (TT1000 and TT3000).
▪ Conductive material on a sensing cable for water or aqueous solutions.
The material
might be metal filings, concrete dust, flux, mastic, or other construction debris, or
carbon-based dust from air-handling units, printers, or copiers.
While service alarms should be investigated, they do not threaten the operation of the
system. The TTDM and TTSIM will continue to detect leaks during a service alarm.
However, service alarms may affect the accuracy of leak location in certain cases.
THE SERVICE ALARM
When the TTDM detects a condition requiring service (such as described above), it
signals the event by taking the following actions:
▪
Sounds an intermittent beep.
▪ Illuminates the yellow Service LED.
▪ Switches the service relay to alarm state.
▪ Changes the LCD display to the following:
CH01 USER_LABEL_0001
Service Req’d [147]
HH:MM DD-MON-YYYY
The number in square brackets indicates the estimated location of the material causing
the alarm. The number is shown with square brackets to indicate that the value is only an
estimate.
H
INT
:
Because the cause (concrete dust, for example) of low-level current may be
distributed over several feet/meters of cable, it is not always possible for the TTDM-Plus
to report an accurate location. However, the indicated location is always a good point from
which to begin a troubleshooting procedure.
The following actions should be taken:
►
Silence the audible alarm.
►
Clear the cable.
N
OTE
:
When the cable is cleared, the yellow Service LED, the alarm relay, and the LCD
display will automatically return to their normal (non-alarm) state. No reset is required.