Spectrex 20/20U (UB) - UV Flame Detector - Manual (Page 22)

Spectrex Inc. - SharpEye™ UV Flame Detector Manual – TM 20/20UB Rev. E, August 2004
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4.5 Built-In-Test (refer to 2.5)
a. Principles
The detector’s Built In Test (BIT) checks the following:
• Electric circuitry
• Sensor
• Window cleanliness
The detector can be set to perform the BIT automatically and manually
(SW1-2 = ON) or manually only (SW1-2 = OFF).
b. Principles
If the BIT succeeds, the detector’s status turns to Normal.
If the BIT fails, a second BIT is executed after a delay of 6 seconds.
If the second BIT succeeds, the detector’s status turns to Normal; otherwise the
status is turned to Fault.
c. Manual BIT only (SW1-2= OFF):
The BIT is initiated manually by momentarily connecting terminal No. 3 with
terminal No. 2.
A successful manual BIT activates the following:
• Fault Relay is closed.
• Alarm Relay is activated for 3 seconds (only if SW1-6 = ON).
• Accessory Relay is activated for 3 sec (only if SW1-7 = ON).
• 4-20mA Output current will be 20mA (only if SW1-6 = ON) or 16mA
(Only if SW1-7 = ON and SW1-6 = OFF).
• The yellow LED blinks at 0.5Hz rate.
Unsuccessful BIT activates the following:
• Fault Relay is released.
• 4-20mA output indicates Fault condition (2mA).
• The yellow LED blink (at 2Hz rate)
Important Note!
If SW1 switches 7 or 6 are in their “ON” position the Alarm and
Accessory Relays will be activated during a MANUAL BIT, therefore,
automatic extinguishing systems or any external devices that may be
activated during BIT must be disconnected.