Fire Alarm

Daylight Savings Time - Can this affect the operation of a Fire Alarm System?

With a land mass close to 7.7 million square kilometres, Australia is the world's sixth largest country and is divided into three separate time zones.

Daylight Saving Time (DST) is the practice of advancing clocks one hour during the warmer months of the year. In Australia, Daylight saving is observed in New South Wales, Victoria, South Australia, Tasmania, and the Australian Capital Territory.

Daylight saving is not observed in Queensland, the Northern Territory or Western Australia.

Heat Detectors - Principle of Operation

The third instalment of the Principle of Fire Safety series looks at heat detectors, one of the four methods of detecting fire through the the by-products of combustion. This is an area of fire safety that has been rapidly evolving over the last 20 years.

Research and development has improved well established detection technologies and provided an array of new technologies to improve fire detection while also being less susceptible to the causes of false alarms.

Before we go any further it's important to lay the foundation for what is fire; fire also known as combustion is a sequence of exothermic chemical reactions between a fuel and an oxidant accompanied by the by-products of combustion being; heat, smoke & electromagnetic radiation (light). Personally I think a illustration explains this chemical reaction in terms easier to understand.

It is also important to recognise that smoke is an aerosol or mixture of particulates suspended in air that comprises a collection of airborne solids, liquid particulates and gases emitted when a material undergoes combustion.

This is important because each of the four detection technologies are designed to respond to one of the three by-products of combustion. There are four principal methods for detecting fire explored in this article including; Heat, Smoke, Flame and Combustion detectors.

Fire Alarm Systems - Principle of Operation

Rarely in the movies do you ever see a Fire Indicator Panel (FIP), more often than not you will see an American style 'pull station' - the equivalent of a Manual Call Point or Break Glass Alarm found in Australia.

A Fire Indicator Panel (FIP) is probably best described as the 'brains' of a fire detection and alarm system. A fire indicator panel comprises control and indicating equipment (c.i.e) that combined together form an integrated system. These core components comprise;

How long will my fire panel battery last?

I have been asked to discuss the reasons why we recommend the installation of a second (tertiary) set of backup batteries installed in parallel to the existing main (secondary) batteries installed within a fire panel during a planned mains power shut down.

The building owner contacted us to advise they plan to shut down the power to their building for a period of 8 - 12 hours for maintenance purposes. The planned shut down will also remove mains power from the fire panel.

There is a small fire panel installed on site designed to Australian Standard AS1670.1-2004, fitted with an occupant warning system.

In this example the customer wanted to know if it is necessary to install tertiary backup batteries.

End of Line (EOL) values


Wormald ST/SMT Panel

Although there are not many of these panels left any more, I thought i would add in a few of the different end of line values for the various zone cards for this panel. The ST panel can be identified by the rotary knobs on the front with left position alarm test, centre position normal, and right position is reset / isolate.

Minerva, 138, 24v, 82K 
SS Thermal MK4, 152 = 12v, 4K7 
Thermal, 181 = 24v, 12K 
Minerva, 256 = 24v, 82K 
Minerva MK3, 312 = 24v, 82K 
SS Thermal, 420 = 24v, 12K 
Minerva, 511 = 24v, 82K