Hochiki ESP Addressable Smoke Detector

FAQ

What is the advantage of photoelectric detection over ionisation?

The ALN-EN’s photoelectric detection technology offers several advantages over traditional ionisation sensors. Photoelectric sensors are more effective at detecting slow-smoldering fires that produce larger smoke particles, which are common in residential and commercial settings. They are less prone to false alarms from cooking fumes, steam, and dust compared to ionisation sensors. Additionally, photoelectric sensors do not contain radioactive material, eliminating disposal and regulatory concerns associated with ionisation detectors. The ALN-EN’s High Performance Chamber Technology provides such improved sensitivity and reliability that it removes the need for ionisation sensors in most applications.

Why is the smoke chamber removable?

The removable smoke chamber design is a significant maintenance advantage. During routine servicing, the chamber can be easily detached from the sensor head for thorough cleaning without requiring complete detector removal from the ceiling or dismantling of wiring connections. This simplifies maintenance procedures, reduces service time, and ensures the chamber can be cleaned effectively to maintain optimal detection performance. If a chamber becomes damaged or contaminated beyond cleaning, it can be replaced without replacing the entire sensor, reducing long-term maintenance costs.

What do the different LED colours indicate?

The ALN-EN features twin LEDs that provide clear status indication visible from 360 degrees. The LEDs display green when the sensor is being polled by the fire alarm control panel, confirming normal communication and operation. During a fire alarm condition, the LEDs turn red to provide immediate visual confirmation of the detector in alarm. The LED operation can be set to either pulsing or non-pulsing mode from the control panel, allowing customization based on site requirements. This dual-colour indication assists engineers during commissioning, helps maintenance personnel verify device operation, and aids emergency responders in quickly identifying the alarm source.

What is variable sensitivity and why is it important?

Variable sensitivity allows the ALN-EN to be calibrated from 2% to 4.5% obscuration per meter to suit different environmental conditions and application requirements. Lower sensitivity settings (higher percentage) are appropriate for areas prone to dust, vehicle exhaust, or other particulate matter that might cause nuisance alarms. Higher sensitivity settings (lower percentage) provide earlier detection in clean environments or where rapid fire detection is critical. This flexibility ensures optimal performance across diverse applications, from warehouses to offices, without requiring different detector models. The sensitivity can be adjusted through the control panel without physical access to the detector.

Which fire alarm control panels is the ALN-EN compatible with?

The ALN-EN is designed for use with Hochiki fire alarm control panels that support the ESP (Enhanced Systems Protocol) analogue addressable protocol. This includes Hochiki’s range of intelligent fire alarm systems such as the FIREscape addressable panels and other ESP-compatible control equipment. The digital communication protocol allows the panel to receive detailed analogue information from the sensor, monitor device health, adjust sensitivity, control LED operation, and receive early warning of developing fire conditions. Always verify compatibility with your specific control panel model before installation.

What bases are compatible with the ALN-EN?

The ALN-EN is compatible with several Hochiki detector bases including the YBN-R/3 (standard base), YBO-R/SCI (short circuit isolator base), YBO-BS (sounder base), YBO-BSB2 (beacon sounder base), and YBN-R/3(SCI) (standard base with isolator). The adjustable base fixing centres from 48mm to 74mm provide flexibility for mounting on various back boxes and ceiling installations. The sensor features a locking mechanism that securely attaches to the base, preventing accidental removal while allowing authorized detachment for maintenance.

Can the ALN-EN be used in dusty or humid environments?

The ALN-EN is designed to operate in demanding conditions with humidity up to 95% RH non-condensing at 40°C and an IP42 ingress protection rating providing protection against solid objects over 1mm and water dripping at an angle up to 15 degrees. However, in particularly dusty environments, the variable sensitivity feature should be utilized to set an appropriate threshold that balances detection capability with false alarm prevention. Regular maintenance and chamber cleaning will ensure optimal performance in challenging environments. For extremely harsh conditions, consultation with Hochiki or a fire system designer is recommended to ensure the ALN-EN is appropriate for the specific application.

How does the improved signal-to-noise ratio reduce false alarms?

The High Performance Chamber Technology in the ALN-EN allows the sensor threshold level to be increased while maintaining excellent smoke detection capability. This means the sensor can distinguish between actual smoke particles from fire and background “noise” such as dust, water vapor, or other airborne particles more effectively. By improving the signal-to-noise ratio, the sensor is less likely to misinterpret environmental conditions as fire, significantly reducing false alarms. This is particularly valuable in environments with challenging conditions like kitchens, manufacturing areas, or locations with temperature fluctuations that might trigger less sophisticated detectors.

What is the typical current consumption and why does it matter?

The ALN-EN has a low quiescent current of 400 μA typical during normal monitoring operation, with an ultra-low power mode of 120 μA typical. This low power consumption is important for several reasons: it allows more devices to be connected to a single loop circuit without exceeding power supply capacity, reduces overall system power requirements and operating costs, minimizes heat generation in the detector, and ensures the system can operate longer on backup battery power during mains failure. The efficient power design is particularly beneficial in large installations with hundreds of devices.

Are there different colour options available and why?

Yes, the ALN-EN is available in three colour options: ivory (ALN-EN), white (ALN-EN(WHT)), and black (ALN-EN(BLK)). These options allow the detector to be matched with ceiling colours and interior design aesthetics, making them less visually obtrusive while maintaining functionality. Ivory is the traditional standard colour, white provides a clean modern appearance suitable for contemporary interiors, and black is ideal for dark ceilings, entertainment venues, or locations where a discreet appearance is preferred. All colour variants offer identical performance and specifications.