Det-Tronics U9500 Infiniti Gas Transmitter - Manual (Page 31)

95-8444 29 10.1
TROUBLESHOOTING
Automatic Diagnostics and Fault Messages
The transmitter features self-testing circuitry that
continuously checks for problems that could prevent
proper system response. When power is applied, the
microprocessor automatically tests the unit. If a fault is
detected during this warmup mode, it will be indicated
on the display and must be reset to clear. In the Normal
operating mode, it continuously monitors the input signal
from the sensor to ensure proper functioning.
In the event of a system fault:
• The display identifies the nature of the fault using a
fault message. Refer to Table 15 for an expanded
explanation of the messages.
• The normally energized Fault relay (on relay models)
is de-energized.
• The dc current output drops to less than 1.0 mA.
NOTE
The fault message will be shown for about
1.5 seconds out of every 3 seconds. The gas
concentration at the sensor will be displayed
during the remaining time. If more than one fault
should occur, the highest priority fault will be
displayed. (Table 15 lists the faults in order of
priority.)
In the event of an alarm condition and a system
fault both occurring:
• In most cases, the first condition that occurs will be
indicated by the current and relay outputs and on
the display.
• The exceptions are “CAL ABORTED” and “SENSOR
E.O.L.” faults, which both can occur during the
calibration procedure. If an alarm occurs with these
faults, the alarm will over-ride the fault and will be
indicated.
Prioritized Faults
The faults are prioritized, with the highest fault being the
only one displayed (see Table 15 for a prioritized listing).
If an additional fault exists, it will be displayed after the
higher priority fault has been cleared.
Clearing Faults
Generally, faults that occur while in the normal mode are
self-clearing once the fault condition has been corrected.
Faults that occur while in the warmup and calibration
modes require a manual reset to clear (using either an
externally connected reset switch or the Cal magnet).
After the fault condition has been corrected, the fault
relay automatically switches to the normal (energized)
state, the dc current output returns to normal, and the
fault message turns off.
CaUTiOn
The fault detection circuitry does not monitor the
operation of external response equipment or the
wiring to these devices. It is important that these
devices be checked periodically to ensure that
they are operational.