ATJ-EN (WHT) Addressable Multi-Heat Detector
The ATJ-EN is an addressable analogue multi-heat sensor using the Hochiki ESP protocol. It combines a fixed (variable) temperature element with a rate-of-rise element; the control panel may be configured to use either element or both for alarm decisioning. Twin 360° LEDs indicate status (green when polled, red in alarm) and LED pulsing behaviour can be controlled from the panel.

Key benefits

• Reliable multi-heat detection — fixed temperature plus rate-of-rise selection for different applications.
• Addressable ESP communications — electronic addressing and unique device type code for intelligent loops.
• Clear visual status — twin 360° bi-colour LEDs, panel-controllable pulsing.
• Low power consumption suited to addressable loops.
• Compatible with common Hochiki bases (e.g. YBN-R/3); SCI variants require specified SCI bases.

Use cases

• Commercial and light industrial installations where heat detection is preferred or required.
• Addressable fire alarm systems requiring EN54-5 approved heat sensing devices.
• Sites where LED indication behaviour needs to be controlled centrally from the panel.

Compliance & installation

• EN54-5 (Classes A1/B/C), LPCB and VdS approvals (SIL‑2 variants available).
• Operating range 17–41 V DC (ESP loop voltage). Consult the official datasheet for installation, mounting base compatibility, and exact electrical figures for specific variants (SCI / SIL variants have separate datasheets).
• Must be installed, configured and commissioned by a competent/qualified fire alarm engineer in accordance with local regulations and the manufacturer’s instructions.

For the certified, variant-specific figures (exact quiescent/alarm current for a given SKU, detailed mounting instructions and dimensional drawings) consult the official ATJ-EN datasheet/installation manual.