Built-In-Test
TM 787100 Rev (Af), May 2019
33
4.4.3.2
Automatic BIT
The detector automatically performs a BIT every 15 minutes.
A successful BIT does not activate any indicator.
•
The fault relay remains closed (normal).
•
The LED continues to flash (1Hz) at green.
•
The 4
–
20mA output continues to indicate 5mA.
An unsuccessful BIT sequence activates the following:
•
The fault relay is opened.
•
4
–
20mA output indicates BIT FAULT (2mA).
•
The LED flashes (4Hz) at yellow.
•
BIT procedure will be performed every 1 minute.
4.4.4
Manual BIT only
The BIT is initiated manually by momentarily connecting PIN No. 3 (or
yellow wire) with PIN No. 2 (or black wire). A successful manual BIT
activates the following:
•
Fault relay remains closed
•
Alarm relay is activated for 3sec (only when Function Alarm BIT at YES)
•
4
–
20mA output current will be 15mA (only when Function Alarm BIT at
YES).
•
The LED will illuminate at red for 3sec
Unsuccessful BIT activates the following:
•
Fault relay is opened
•
4
–
20mA output indicates BIT fault condition (2mA)
•
The LED flashes (4Hz) at yellow.
During a manual BIT, if function alarm BIT is in YES position, the alarm relay will
be activated and the 4
–
20mA outputs will initiate 15mA. Therefore, automatic
extinguishing systems or any external devices that would be activated under
actual alarm conditions should be disconnected during a BIT.
