4 detector states – Spectrex 20/20L (LB) - UV/IR Flame Detector User Manual

Page 23

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Spectrex Inc. - SharpEye

TM

UV/IR Flame Detector Manual – TM20/20LB Rev E, August 2004

15

4.4 Detector States

The detector can be in one of the following states:
Normal:

The detector is functioning.

BIT:

The detector performs a BIT.

IR Detection:

IR sensor is in Detection level.

UV Detection:

UV sensor is in detection level.

Warning:

The detector detects a fire and changes into its warning-pre-
alarm state.

Alarm:

The detector detects a fire and changes into fire alarm state.

Latched Alarm: The alarm outputs are latched after Alarm state due to the

detection of a fire even when the fire has already been
extinguished.

BIT Fault:

A fault is detected during BIT sequence. The detector will
continue to detect fire if the alarm conditions occur.

Fault:

A fault is detected when the power supply is too low or during a
software fault.


In each state the detector will activate different outputs as specified in Table 6.

Table 6. Output Signals Versus Detector State

Detector
State

SW1

Yellow
LED

Red
LED

Alarm
Relay

Accessory
Relay

Fault
Relay

4-20mA
Output

Fault

2Hz

OFF OFF

OFF

OFF

0mA

BIT Fault

2Hz

OFF OFF

OFF

OFF

2mA

Normal

0.5HZ

OFF OFF

OFF

ON

4mA

IR
Detection
only

0.5HZ

OFF OFF

OFF

ON

8mA

UV
Detection
only

0.5HZ

OFF OFF

OFF

ON

12mA

Warning

SW1-4 on 0.5Hz

2Hz OFF

ON

ON

16mA

Alarm

0.5Hz

ON

ON

* ON

20mA

Latch

SW1-1 on 0.5Hz

ON

ON

*

ON

20mA

Warning
at BIT
Fault

2Hz

2Hz

OFF

ON

OFF

16mA

Alarm at
BIT Fault

2Hz

ON

ON

* OFF

20mA

* Depends on SW

1

-4 set.

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