Smoke Detector Testing

Smoke Detector Testing 

Requirements for testing of smoke detectors vary by country, the common need is for a functional test where smoke, or simulated smoke, is introduced through the vents of the detector to the sensor.

Functional testing is required by all national standards around the world, including BS: 5839, DIN 14675 and NFPA 72. BS:5839-1 which, at its last update, stated: “Multi-sensor fire detectors should be physically tested by a method that confirms that products of combustion in the vicinity of the detector can reach the sensors and that the appropriate response is confirmed at CIE.” (45.4(j).  It highlights that each sensor on which a fire detection decision depends (e.g. smoke, heat, CO) should be physically tested individually. This means that functional testing needs to be carried out on both the smoke and heat sensors, this ultimately requires spending more time under each detector and on a site where multi-sensors are the dominant device, this can add significant time to a site visit.  In this situation access to an all-in-one test solution adds real value, not only does it mean less time spent changing between testers but it also means less tools are required to be carried around site – reducing disruption and improving productivity.

A functional test should be carried out using an appropriate test tool which is designed for purpose and will cause no damage to the detector under test.

If you have standalone smoke detector, test the alarm monthly. Replace the batteries at least once every year. Replace the entire smoke alarm every 10 years. Press and hold the test button on the smoke detector. It can take a few seconds to begin, but a loud, ear-piercing siren should emanate from the smoke detector while the button is pressed. If the sound is weak or non-existent, replace your batteries. Most of Standalone detectors have either a blinking or a solid light that glows to let you know that the alarm is getting power. 

Before starting the testing job for 2wire / 4wire smoke detector, take the proper work permit and inform to all the respective departments / authority. Then do force the respective logics or interlocks if any (like fire suppression systems activation etc).

§  Prior to testing of Smoke detector see the LED status of the Smoke Detector it should be blinking red.

§  Check the voltage of the Smoke Detector, it should be + 30 Volts DC. This can be checked at the addressable base of the detector.

§  Now Smoke Detector is healthy and it is ready for testing.

§  Clean the Smoke Detector’s dust by cotton cloth and blower

§  Apply the aerosol spray to the Smoke Detector by solo Smoke detecting gun with the help of the Solo A10S/A5 aerosol bottle.

§  Keep applying aerosol spray for 10 seconds.

§  After 10 seconds LED status of the Smoke detector will change from the steady blinking red to steady red and after that alarm appears and hooter is activated on the fire alarm panel.

§  To silence the hooter press acknowledge key on the Fire Alarm Panel.

§  After alarm appears remove Smoke detecting test gun from Smoke Detector.

§  Note down the alarm tag and descriptions from the HMI or workstation. The alarm details must match with the smoke detector tag number and installed location.

§  Confirm the smoke detector activation status from the respective graphics page. You have to visually identify the colour change signals of the respective smoke detector on the graphics.

§  Reset the alarm of the Smoke detector from Fire Alarm Panel.

§  The LED status will change from steady red to blinking red.

§  Smoke Detector is now working normally.

§  Repeat the above procedure for all the remaining smoke detectors.

§  Normalize the forced interlocks or logics if any.

§  Close the work permit.

Note: The mentioned voltages or LED colors sequence may change as per the vendor or model of the smoke detectors. Solo Smoke Aerosols is approved all over the world, its Non-toxic & Silicone free. Solo smoke aerosols (used with the Solo 330/332 dispensers) deliver smoke particles to the detector under test replicating the conditions of smoke from a fire. Our range of smoke aerosols has recently increased to allow continued use of Solo 330/332 dispensers in full compliance with latest regulations.

BS:5839-1 as the example once again, the 2017 update to the standard covered this by stating: “For remotely situated or hard-to-access detection equipment, consideration needs to be given to the feasibility of testing and maintenance at the design stage.” (Clause 22.1).

Unique Formula Identifier (UFI), is a 16 character alphanumeric code which will soon be required to appear on the labelling of all products classified as hazardous by the ECHA. This new directive is designed to enable faster identification of product contents, with the UFI code used to detail the composition, product category and toxicological information of the product and enable faster reaction and treatment of potential harm.

UFI codes will become mandatory on relevant products across Europe from January 2021.

Do remember A10S is globally approved non-flammable UL listed product.

Duct Smoke Detector vs. Duct Detector

In Duct Smoke Detector vs. Duct Detector for FSD

"For fire smoke dampers, should I use an in-duct spot type smoke detector or a duct detector?"

Sampling tube style duct detectors are listed for a minimum air velocity of 100 fpm (feet per minute). If you are to ensure the rating of the wall at duct penetrations (dampers), you must provide coverage per The International Building Code IBC 2012 Edition Section 717.3.3.2.  

717.3.3.2 Smoke damper actuation. The smoke fire damper shall close upon actuation of a listed smoke detector or detectors installed in accordance with Section 907.3 and one of the following methods, as applicable:

1. Where a smoke damper is installed within a duct, a smoke detector shall be installed in the duct within 5 feet (1524 mm) of the damper with no air outlets or inlets between the detector and the damper. The detector shall be listed for the air velocity, temperature and humidity anticipated at the point where it is installed. Other than in mechanical smoke control systems, dampers shall be closed upon fan shutdown where local smoke detectors require a minimum velocity to operate.

2. Where a smoke damper is installed above smoke barrier doors in a smoke barrier, a spot-type detector listed for releasing service shall be installed on either side of the smoke barrier door opening.

3. Where a smoke damper is installed within an air transfer opening in a wall, a spot-type detector listed for releasing service shall be installed within 5 feet (1524 mm) horizontally of the damper.

4. Where a smoke damper is installed in a corridor wall or ceiling, the damper shall be permitted to be controlled by a smoke detection system installed in the corridor.

5. Where a total-coverage smoke detector system is provided within areas served by a heating, ventilation and air-conditioning (HVAC) system, smoke dampers shall be permitted to be controlled by the smoke detection system.

The 1st method above states that you must provide a smoke detector installed in the duct within 5’ of the fire smoke damper, and that the smoke detector shall be listed for the air velocity.  If you shut down the fan, there will not be a minimum air velocity of 100 fpm to achieve the proper listing of a sampling tube style duct detector (System Sensor D4120 for example).  Notice that this same paragraph states that “Other than in mechanical smoke control systems, dampers shall be closed upon fan shutdown where local smoke detectors require a minimum velocity to operate”.

What if we decide to use sample tube duct smoke detectors?

If we are using duct detectors for damper control, then whenever the fan is off, the dampers must be shut since the duct detectors such as the System Sensor D4120 require a minimum velocity of 100 fpm to operate.  Does this mean we then have to monitor fan status, and shut dampers upon fan shutoff, or shall the mechanical contractor have to inter-tie with all the dampers associated with that fan?  If we decide to monitor the fan, that creates another issue—per the IMC (International Mechanical Code), if a damper has automatically been activated to close, the associated fan must be shutdown.  Picture this scenario—AHU1 turns off, so we shut down the dampers.  The damper circuit we are controlling also serves dampers associated with AHU2, therefore we must shut that one down as well.  Since AHU2 is serving other areas of the building, we must shut those circuits of dampers as well, and so on until the whole building has typically been shut down for HAVC equipment including dampers.

What if we use spot type In-Duct Smoke Detectors?

On the other hand, if we are protecting the fire smoke dampers with an in-duct detector, you can have the fan shut down upon duct detector for the fan, and the dampers throughout the rest of the building may remain open and the other fans may remain on.  The damper is still protected with the in-duct smoke detector to ensure the rating of the wall to shut the damper upon detection of smoke, and if the in-duct smoke detector activates, then we go through the shut-down process of the fans and dampers throughout the building as exampled above.  Note that in-duct detectors have a listed minimum air velocity of 0 fpm, meaning that it does not “require a minimum velocity to operate“, therefore not requiring shutdown of the building upon a single fan being shut down.

Building owners really don’t like when their building heats up because they are servicing one of their fans, or one of the many fans in their building turns off due to a number of circumstances that are not necessarily indicative of a fire, and our fire alarm system shuts down all HVAC movement in the building.  Mechanical contractors don’t like it when they are forced to interface with individual dampers to close upon fan shutdown.  And finally, electrical/mechanical contractors really don’t like it when we force them to give us a true status of the fan via a Current or Differential Pressure switch when the fan is not a part of a smoke control system and it was not shown on their drawings or bid docs.