Introduction to the Apollo XP95 Heat Detector and its key features
The Apollo XP95 Heat Detector (part number 55000-420APO) is an addressable fixed-temperature heat detector designed for use on XP95 analogue addressable loops. Built around a single NTC thermistor, the detector provides an analogue temperature count and generates a dependable alarm when the temperature reaches 55 °C (A2S class). Its design focuses on reliable operation in environments where smoke detection is impractical or frequently gives nuisance alarms such as car parks, loading bays, warehouses and other dusty or normally smoky locations.
- Fixed-temperature alarm:A2S class, alarm at 55 °C.
- Addressable XP95 protocol:Fully compatible with XP95 and related addressable control equipment.
- Analogue thermistor output:Single NTC thermistor provides analogue temperature counts for monitoring and diagnostics.
- Low airflow resistance housing:Designed to resist the effects of wind and pressure changes in exposed locations.
- Remote LED option:Red alarm LED on unit and remote indicator terminals for visible alarm indication at a remote point.
- Rugged environmental performance:Wide operating temperature, high humidity tolerance and an approximate IP53 rating.
- Long manufacturer warranty:10-year warranty as listed by Apollo.
Detailed specifications and benefits
Understanding the specifications behind the Apollo XP95 Heat Detector helps clarify why it is widely specified for industrial and challenging environments. Below is a concise breakdown of the key technical details and the practical benefits they deliver.
- Manufacturer / Series:Apollo XP95 (Part no. 55000-420APO)
- Heat classification:A2S (fixed alarm at 55 °C)
- Thermistor and analogue response:Single NTC thermistor produces an analogue temperature count (nominal analogue = 25 counts, alarm threshold = 55 counts)
Benefit: The analogue output lets addressable control equipment monitor trends in local temperature, enabling early diagnostics and confirmation of sensor health before a full alarm condition. The fixed 55 °C threshold makes the unit predictable and ideal where slow thermal rises or background contaminants would interfere with smoke sensing.
- Supply Voltage:17 6 28 V dc (protocol modulation 5 6 9 V p-p)
- Protocol / Compatibility:XP95 addressable (compatible across the XP95 family)
- Quiescent Current:Approximately 250 A at 24 V dc
- Power-up Surge:Approx. 1 mA; max power-up time 4 s
- Remote LED Output:Remote indicator terminals (+R/ -R); red alarm LED fitted to unit
Benefit: Low quiescent current reduces loop loading, and XP95 addressability allows each detector to be uniquely identified on the loop. Remote LED terminals make it simple to provide local indication where the detector is out of sight.
- Operating Temperature:-20 to +70 °C
- Humidity:0 6 9% RH (no condensation or icing)
- IP Rating:Approx. IP53
- Dimensions:Diameter ≈100 mm; Height ≈42 mm; Weight ≈105 g
- Housing:White polycarbonate with nickel-plated stainless steel terminals
Benefit: The broad temperature and humidity tolerances and low airflow resistance housing make the XP95 heat detector suitable for exposed indoor and semi-exposed spaces (for example, multi-storey or open car parks). The compact, lightweight polycarbonate housing is robust for most installation environments.
- Standards:EN54-5 (confirm variant for certified compliance)
- Approvals:LPCB, VdS, CPR and others depending on variant (check datasheet)
- Manufacturer Warranty:10 years
Benefit: Compliance with recognised standards and long manufacturer backing gives designers and installers confidence that the device will meet regulatory and performance expectations when the correct variant is used and installed per the datasheet.
Use cases and scenarios where the detector excels
The Apollo XP95 A2S 55 °C heat detector is engineered for locations where smoke detectors are not ideal, where environmental contaminants or airflow would cause false alarms, or where heat rise is the most reliable indicator of an incident. Typical use cases include:
- Car parks:Diesel exhaust, vehicle emissions and dust commonly trigger optical smoke detectors; a heat detector provides stable, nuisance-free protection.
- Loading bays and warehouses:Forklift exhaust, dust and high ceilings make smoke detection problematic; fixed-temperature heat detectors remain effective.
- Plant rooms and engine rooms:Areas with controlled air movement, heat-producing equipment and occasional smoke/soot benefit from heat-based detection.
- Industrial environments:Workshops and manufacturing areas where dust, fumes or steam are present.
- Enclosed garages and service tunnels:Where airflow and contaminants affect smoke sensor reliability.
In practice, designers often specify the XP95 heat detector in combination with other detectors (smoke detectors, multi-sensor units) to provide layered protection. For example, heat detectors can protect zones prone to nuisance alarms while smoke detectors cover cleaner internal spaces for earlier detection of smouldering fires.
How it compares with similar products
When choosing a detection strategy, it helps to understand how the Apollo XP95 A2S 55 °C compares with other detector types and alternatives.
- Smoke (optical or ionisation) detectors are generally more sensitive to early, smouldering fires but are vulnerable to nuisance alarms in dusty, smoky or fume-laden environments.
- The XP95 heat detector sacrifices some early detection sensitivity in exchange for robustness: it triggers on a defined thermal threshold, reducing false alarms in harsh conditions.
- Rate-of-rise detectors alarm on rapid increases in temperature and can detect fast, flaming fires earlier than fixed-temp units in some scenarios.
- Fixed-temperature detectors like the XP95 A2S 55 °C are preferred where ambient temperature variability or ventilation could mask rate-of-rise signals, or where a stable, known threshold is required for design or insurance reasons.
- Addressable detectors give unique identification and diagnostic capability on a single loop, reducing commissioning complexity and improving fault/maintenance reporting.
- For large or complex sites, the XP95 addressability significantly reduces wiring, simplifies panel integration and improves event location speed compared with conventional devices.
Overall, the XP95 A2S 55 °C occupies a practical niche: a robust, addressable fixed-temperature device that reduces nuisance alarms while providing reliable thermal-triggered detection where smoke sensing is impractical.
Customer feedback and installer notes
Direct public customer reviews for this exact part are typically held by distributors, installers and end-users; however, typical installer feedback for Apollo XP95 detectors (drawn from trade commentary and installer forums) highlights several recurring positives:
- "Reliable in harsh environments" (typical comment): installers note consistent performance in car parks and warehouses, with few false alarms.
- "Easy integration with XP95 systems": Addressability and low loop current make the detectors straightforward to commission and maintain.
- "Good documentation and long support life": Apollo's datasheets and long warranty period give confidence to specification engineers and maintenance teams.
Note: For verified customer testimonials, check distributor listings, installer case studies or contact Apollo-authorised partners for site references and performance reports.
Conclusion: why the Apollo XP95 Heat Detector is a strong choice
The Apollo XP95 Heat Detector (55000-420APO) is a focused, professional-grade solution for heat-based fire detection on XP95 addressable loops. Its combination of a dependable fixed-temperature threshold (55 °C), analogue thermistor output, low airflow resistance housing and wide environmental tolerances make it especially well suited to car parks, loading bays, warehouses, plant rooms and other locations where smoke detection is impractical or would cause nuisance alarms.
Addressability offers clear operational benefits for installers and facilities managers: simplified wiring, precise location reporting and enhanced system diagnostics. The device combines technical robustness with practical installation features like remote LED outputs and low power draw. Backed by recognised standards (EN54-5 variants) and a 10-year manufacturer warranty, it represents a durable and cost-effective choice for designers and building owners needing reliable thermal detection where smoke sensing is unsuitable.
For exact certification requirements, installation, wiring diagrams and approved variants, always consult the official Apollo datasheet and installation manual and ensure installation is carried out by a competent person in accordance with local regulations. Suggested retail guidance places the detector at around approx. cost price 29.48 and suggested price 35.10.
