Apollo Orbis Optical Smoke Detector, Two Wire, IP44 ORB-OP-12001-APO

Overview

An optical detector looks for smoke by using light, so it responds to smoke rather than to heat. This Apollo detector is one of the Orbis range and comes in a white flame retardant polycarbonate housing.

Its performance is good with black as well as with white smoke, whereas traditional optical detectors perform far better in white smoke than in black.

How it works

• Light scatter: smoke entering the chamber scatters light onto a sensor. The chamber measures back-scattered light as well as the more usual forward-scattered light.
• Sampling: it samples once every four seconds, and algorithms then decide when it should change to the alarm state.
• Drift compensation: dust slowly changes what a sensor reads, so the detector allows for that up to a limit. DirtAlert then shows that the limit has been reached.

Where to use it

Its algorithms are designed to reduce alarms from smoke from smoking materials.

Steam, cooking fumes and heavy dust can still set off an optical detector, so a heat detector is often the better choice in kitchens and plant rooms.

Its operating range of -40ºC to +70ºC is wide, while IP44 gives only moderate protection against dust and splashes.

What the figures mean in practice

• Current at rest: the 95 µA figure at 24 V is what each detector adds to a circuit when idle. Compare the total with the panel's allowance.
• Alarm voltage: the red alarm LED lights from a minimum of 5 V, and the holding voltage runs from 5 V to 33 V.
• Reset: the supply has to fall below 1 V for about one second for the alarm to reset.

Installing it

Allow time after power up, which is < 20 seconds. Polarity reversal must not last more than 200 ms, which is why the StartUp check is worth watching on first power up.

As a rule, detector heads are sold without a base, so allow a suitable mounting base for each position.

Planning your system

A conventional system wires its devices in zones, so the panel names a zone and not a single head. The fire alarm system guide compares that with addressable systems.

For loop-based work, the other Apollo smoke detectors cover addressable and wireless systems.

Standards and ratings explained

EN54-7 is the standard for point smoke detectors. CPR refers to the Construction Products Regulation, and the detector complies with its essential requirements.

SensAlert indicates that the sensor is not operating correctly, so treat that signal as a reason to replace or service the head.