Apollo XP95 Optical Smoke Detector, Black 55000-660APO

What this optical smoke detector does

This Apollo smoke detector watches for the early smoke of a slow fire, before it has produced much heat or flame.

It suits installers and engineers building or extending a loop on an addressable fire alarm panel. The black housing may suit dark ceilings and interiors.

How does light scatter detection work?

Inside the case is a light proof chamber with an infrared LED and a photo-diode, which is a sensor that reacts to light. They sit at an angle, so in clear air no light from the LED lands directly on the sensor. The LED fires a burst of light every second.

Smoke entering the chamber bounces some of that light onto the photo-diode. Denser smoke generally means a stronger signal.

• Analogue reading: the detector sits at 25±7 counts in clean air, and the count climbs with smoke density. A count of 55 lines up with the EN 54 alarm sensitivity level.
• Addressable signalling: the panel interrogates each device in turn over the loop. Every device has its own address, so the panel can point to the one reporting.
• The XP95 protocol: a protocol is the digital language a panel and its devices must share. The smoke detector and panel must match.

Where to use it

Corridors, stairwells and other routes out of a building are natural positions. So are rooms where a fire would tend to smoulder first, such as those holding paper, soft furnishings or cabling.

It is unaffected by wind, though moving air can still carry smoke away from a detector, so follow your system design for siting. Avoid spots with condensation or icing.

Any detector that senses particles can react to steam, dust or cooking fumes. Keep it away from kitchens and shower rooms.

What the figures mean in practice

• 0.12 dB/m threshold: dB/m describes how much smoke dims light over one metre. A low figure means the detector reacts while smoke is still thin.
• Sampling once per second: the value is current when the panel next interrogates the detector.
• 340 µA standby draw: ten detectors add 3.4 mA to a loop calculation. Power-up surge is 1 mA for 1 second per detector, so allow for it as your panel maker's loop calculation directs.

Installing it

• Loop wiring: one two wire loop carries data and power in and out of the base. There is no separate supply to run.
• Remote indicator: connect a standard high-efficiency red LED across +R and -R. No series limiting resistor (fitted in line to limit an LED's current) is needed, which keeps the job simple where a repeat light sits outside a locked room.
• Earth: an earth connection terminal is also provided at the base.

Planning your system

Allow a mounting base for each detector. The system also needs an addressable panel using one of the three protocols, and a loop calculation covering every device.

Standards and approvals explained

• EN 54-7: the European standard for point smoke detectors. Apollo measures sensitivity, vibration, impact and shock to it.
• CPR: the Construction Products Regulation 305/2011/EU, which sets rules for products built into buildings.
• LPCB: the Loss Prevention Certification Board, an independent body that certifies fire and security products.
• EMC Directive 2014/30/EU: rules that limit electrical interference, both given off and received. The detector complies when used as Apollo directs.