32 • T3A Transmitter
3. Use the ADD and SUB buttons to toggle between the “Auto Reset” and “Latch” options.
4. Press the MENU button to select the desired setting and to advance to the Relay 2
latching/auto reset setting screen.
NOTE:
For auto resetting alarms, the alarms will NOT deactivate until the gas level reading
at the sensor has fallen 10% below the alarm set-point. For latching alarms, the gas
level reading MUST be below the alarm set-point before the alarm can be
deactivated. The alarms will NOT activate, even in the presence of gas, until you have
exited the menu mode for approximately 1 minute.
Relay 2: Latching/Auto Reset Setting
1. If necessary, enter the Product Settings and Configuration menu by pressing and holding
the MENU button for 6 seconds.
2. Press and release the MENU button until the Relay 2 Latching/Auto Reset screen appears.
3. Use the ADD and SUB buttons to toggle between the “Auto Reset” and “Latch” options.
4. Press and release the MENU button to move through the Product Settings and
Configuration menu or to exit to the normal operating mode screen.
Relay Fail-Safe Setting
From a safety perspective, any unknown situation must be considered potentially hazardous.
When a stand-alone gas detector is unable to detect gas, an unknown condition is created and
precautions must be taken to prevent personal injury or loss of life. This means that the device
must be able to alert the end-user that it is no longer fully operational. This safety function is
made possible by the fault terminal. For more information about the fault terminal and for
instructions on how to wire your device, refer to the Connecting the Fault Terminal section of
this manual.
Site specific circumstances may prevent the use of the fault terminal, leading to potentially
dangerous situations without end-user notification. In response, the T3A provides a relay fail-
safe setting to enhance the safety protection provided when the fault terminal cannot be used.
The relay fail-safe setting reverses the behavior of the relays and allows a deactivated relay to
serve as a warning of a potentially hazardous event. In fail-safe mode, the relays are activated
upon device start-up and deactivated during alarm conditions and when the device is turned
off. Some device failures, such as loss of power and firmware corruption, will also deactivate
the relay.