Heat Detector Testing
Heat
detector can be defined as an element or device that detects changes in heat or
fire. If any heat (change in heat that exceeds the limits of heat sensor
ratings) is sensed by the heat sensor, the heat sensor generates a signal for
alerting or activating a security or protection system to extinguish or avoid
the fire accidents. There are different types of heat sensors, which are
classified based on different criteria such as the amount of heat withstanding
capacity, nature of heat sensing capacity, and so on. Furthermore, the heat
sensors are classified into different types that include analog heat sensors
and digital heat sensors.
Heat
detector can sense the heat (change in heat according to the features of heat
detector used). But, a circuit is to be designed for activating an alarm system
to indicate fire or heat change and for alerting the security or protection
system. Heat detector circuit can be designed using heat sensor.
These heat
detectors are mainly classified into two types based on their operation and
they are “rate of rise heat detectors” and “fixed temperature heat detectors”.
Before starting the job, take the proper work permit
and inform to all the respective departments. Then do force the respective
logics or interlocks if any (like fire suppression systems
activation etc).
§ Prior to testing of Heat
detector see the LED status of the Heat Detector it should be blinking red.
§ Check the voltage of the
Heat Detector, it should be + 30 Volts DC. This can be checked by the
addressable base of the detector. (Digital type detector).
§ Now Heat Detector is
healthy and it is ready for testing.
§ Clean the Heat
Detector’s dust by cotton cloth and blower
§ Apply the heat to the
Heat Detector by solo heat-detecting gun.
§ Keep applying heat for
10 seconds.
§ After 10 seconds LED
status of the Heat detector is changing from steady blinking red to steady red
and after that alarm appears and the hooter is activated on the fire alarm
panel.
§ To silence the hooter
press the acknowledge key to the Fire Alarm Panel.
§ After the alarm appears
remove the heat-detecting test gun from Heat Detector.
§ Note down the alarm tag
and descriptions from the HMI or Graphic workstation. The alarm
details must match with the heat detector tag number and installed location.
§ Confirm the heat
detector activation status from the respective graphics page. You have to
visually identify the colour change signals of the respective heat detector on
the graphics.
§ Reset the alarm of the
Heat detector from the Fire Alarm Panel.
§ The LED status is
changing from steady red to blinking red.
§ Heat Detector is now
working normally.
§ Repeat the above
procedure for all the remaining Heat Detectors.
§ Normalize the forced
interlocks or logics if any.
§ Close the work permit.
Note: The
mentioned voltages, terminals, circuit module names may change as per the
vendor or model of the Heat Detector. Available in both 110 / 120 and 220 / 240
volt versions the Solo 423 and 424 are the professionals’ choice where cables
and leads are acceptable. Unconstrained by energy availability they provide the
quickest of test times and are, perhaps, most suitable for the highest
temperature detectors.
