Apollo Discovery Heat Detector, Addressable, Five Response Modes, White 58000-400APO

What this detector does

This Apollo detector reacts to temperature, so the fumes and dust that upset a smoke sensor do not trouble it in the same way. It is the usual answer for rooms where smoke detection would keep raising unwanted alarms.

It suits installers working on addressable loops and facilities teams dealing with a problem room.

How it works

• Sensing: a thermistor is a resistor that changes value with temperature. Its signal is close to linear from 10ºC to 80ºC.
• Rate-of-rise modes: modes with an R suffix have a rate-of-rise characteristic, meaning they respond to fast temperature climbs. They suit unheated areas where the room may be very low in temperature for long periods.
• Static modes: modes with an S suffix will not respond below their minimum static response temperature, even with high rates of rise. They suit gallies and engine rooms, where large, rapid temperature changes are considered normal.

Where to use it

Kitchens, smoking rooms and other spaces that are dirty or smoky in normal use are the natural positions. It is rated IP44 for 0% to 95% RH, so avoid places where condensation or icing can form.

Heat detection usually responds later than smoke detection, so it is not a like-for-like swap on an escape route. Agree its use with whoever holds the fire strategy.

What the figures mean in practice

• Application temperature: the warmest the room is expected to reach in normal use. Modes 4 and 5 have a maximum of 80°C, which is why they suit hot spaces.
• Static response temperature: the point at which the fixed temperature response acts. Mode 1 is typically 57°C and gives a higher sensitivity to fire than Mode 5.
• 400 µA quiescent: this is the figure to add for each detector in a loop calculation, along with the power-up surge.

Installing it

The incoming and outgoing supply connect through L1 and L2 in the mounting base, so plan a base for each position. An earth connection terminal is also provided.

The two integral LEDs can be lit at any time by the panel, and a flashing mode can be set to show each poll. That can help when commissioning or walking a loop.

Planning your system

The job needs an addressable panel on a compatible protocol, and a choice of mode for each room. Compare other Apollo heat detectors if you need a different protocol or range.

Modes are selected through the panel, so check that your panel supports them before you specify a mode in the design.

Standards and ratings explained

• EN 54-5: the standard for point heat detectors. Its classes, such as A1R and CS, are what the five modes correspond to.
• IP44: protection against objects over 1 mm and splashing water, which suits many indoor service areas.
• NTC: negative temperature coefficient, meaning resistance falls as temperature rises.