September, 2015
814-9
MODEL GT814 NOVA-Sensor
ELITE™
Toxic Gas Detector
High Gas Alarm Mode
If the gas concentration continues to increase above the low alarm setpoint, the following occur:
The present gas concentration is displayed (The SCREEN FLASHES and the LOW
ALARM indicator will remain flashing during this time due to the low gas alarm)
The 4-20 mA signal to external equipment increases to report the present gas con-
centration
When gas concentration reaches the high alarm set point, the red HIGH ALARM
indicator also flashes.
The high alarm relay is activated
!
A typical application might use this high alarm relay contact to shut down
all electrical equipment in the protected area and activate evacuation alarm
signals to alert personnel.
A high gas alarm condition is always locked in or “latched” in the detector, and the
high alarm indicator and the screen will continue to flash even after the gas concen
-
tration has returned to zero.
Activate the
▲MagPoint▲
on the top side of the detector to cancel the high alarm
and return the detector to the protection mode. The high alarm may also be canceled
from a remote location if the reset function has been installed in your detector.
Fault Mode
The NOVA-Sensor
ELITE
is designed to continually monitor it’s own operation and to alert
personnel when it is not functioning properly. This condition is reported as a FAULT. When
a fault condition is active, the following occur:
The SCREEN FLASHES and displays SYSTEM FAULT, and the yellow FAULT indi-
cator flashes (if failure is not due to power source failed)
The 4-20 mA signal to external equipment decreases to 2.0 mA or 0.0 mA
The fault relay contact to external equipment changes state
!
While in fault mode the NOVA-Sensor
ELITE
might not be able to report an alarm condition.
The source of fault conditions should be corrected as soon as possible for safety reasons.
Possible causes of a Fault
Electrochemical fuel cell in the sensor head is past the rated 2 year operating life
Sensor head failure due to intrusion of moisture, dust, or silicones
Sensor failure due to exposure to extremely high concentrations of gas for an ex-
tended period of time
An open-circuit or short-circuit on the wiring going to a remote sensor
24 volt DC power source out of range or failed
Failure of the electronic circuits inside the NOVA-Sensor
ELITE
itself
Maintenance Reminder Mode
We recommend a monthly test of the NOVA-Sensor
ELITE
as explained in the Maintenance
section of this manual. The following reminders may be displayed when additional service
is recommended:
If the sensor display is showing negative gas values of -5 or lower, CHECK
CALIBRATION is displayed on the screen. (The screen illumination will remain dim
during this display)
If the sensor display is showing negative gas values of -10 or lower, SYSTEM FAULT
will display, the screen back light will flash and the yellow FAULT indicator will flash.
90 days after the last full calibration was made, CHECK CALIBRATION is displayed.
After the sensor fuel cell element has been in service for 2 years, the detector will
Summary of Contents for GT814
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