XPander A1R Heat Detector and Mounting Base
XPander incorporates entirely new designs with respect to the wireless communication system. A Radio Interface is connected to the loop. It communicates with the control panel using the Apollo addressable two-wire power and communications system. The interface communicates with the detection and alarm signalling devices by means of radio waves. The detectors are multistate in that they report normal, pre-alarm, fire or fault states to the radio base which transmits the information to the interface. The detectors incorporate drift compensation and report any compensation limit occurring. The radio bases and signalling devices are addressable and use a pre-set analogue value to report via the XP95 or Discovery protocol. Apart from normal and fire the bases can send pre-set analogue values to indicate low battery, detector contaminated, detector tamper and low signal strength fault conditions.
modern styling loop-powered interface operating on 868MHz wireless addresses seen by control panel as normal addresses radio base with wireless circuitry and battery compartment chamber designed to inhibit dirt penetration and thus reduce false alarms automatic drift compensation with DirtAlert™ warning algorithms for transient alarm rejection FasTest™ reduces time taken to test detectors remote test facility 3-5 years battery life
Heat detectors have an open-web casing which allows air to flow freely across a thermistor which measures the air temperature every 2 seconds. A microprocessor stores the temperatures and compares them with pre-set values to determine whether a fixed upper limit–the alarm level–has been reached. In the case of rate-of-rise detectors the microprocessor uses algorithms to determine how fast the temperature is increasing. Static heat detectors respond only when a fixed temperature has been reached. Rate-of-rise detectors have a fixed upper limit but they also measure the rate of increase in temperature. A fire might thus be detected at an earlier stage than with a static detector so that a rate-of-rise detector is to be preferred to a static heat detector unless sharp increases in temperature are part of the normal environment in the area protected by the heat detector.
Maintenance & Service
Detectors should be checked regularly at the intervals indicated by the locally applicable code of practice. Apollo recommends that the detectors be checked at least once a year. If detectors appear not to be functioning correctly they should be returned to Apollo for testing. If detectors are externally dirty they can be cleaned carefully with a damp cloth using a small amount of industrial alcohol.
Heat detectors are used in applications where smoke detectors are unsuitable. Smoke detectors are used wherever possible since smoke detection provides earlier warning of fire than heat detection. There are, however, limits to the application of smoke detectors. Heat detectors should be considered as part of a risk assessment if there is a danger of nuisance alarms from smoke detectors.
The European standard EN54-5 classifies heat detectors according to the highest ambient temperature in which they can safely be used without risk of false alarm. The classes are identified by the letters A to G. (Class A is subdivided in A1 and A2.) In addition to the basic classification, detectors may be identified by a suffix to show that they are rate-of-rise (suffix R) or fixed temperature (suffix S) types. Heat detectors in the XPander range are tested as rate-of-rise detectors or static. The A1R detector is a rate-of-rise detector and the CS is classified as static. The choice of the right type for a particular application is important. Use A1R in areas with normal ambient temperature of less than 50°C and in which sudden increases of heat do not occur in normal circumstances. Otherwise use CS.
There are two heat detectors in the XPander range, designed to suit a wide variety of operating conditions. A Static Heat Detector (CS) which responds only when a fixed temperature has been reached and a Rate-of-Rise Detector (A1R) which has a fixed upper limit, but in addition, measures the rate of increase in temperature.
Wireless Can be used in applications where smoke detectors are unsuitable Ideal for environments that are dirty or smoky under normal conditions CS detectors are ideal for use in environments with rapid temperature fluctuations such as boiler rooms Bi-directional (monitored) radio platform Five-year battery life using standard AA alkaline batteries