# BS 7273-4: Actuation of Release Mechanisms for Doors ## Overview **BS 7273-4:2015 + A2:2023** is the British Standard that governs how **electrically locked or held-open doors on escape routes** must be released in the event of fire or system fault. The standard ensures that escape doors controlled by electricity always release **reliably, quickly, and fail-safe**, maintaining the principle of free egress under the **Regulatory Reform (Fire Safety) Order 2005** and related legislation. --- ## Scope BS 7273-4 applies to: * **Electrically locked doors** (maglocks, solenoid bolts, shear locks, etc.) * **Electrically held-open doors** (e.g. electromagnetic door retainers) * **Doors on escape routes or final exits** where release must be guaranteed It does **not** apply to purely mechanical hardware (e.g. un-locked panic bars). --- ## Categories of Actuation BS 7273-4 defines **three categories of system integrity**, depending on the criticality of the door: | Category | Release Conditions | Typical Applications | | -------------------- | ------------------------------------------------------------------------------------------------------------------------ | ----------------------------------------- | | **A (Highest)** | Must release on fire alarm **and** on virtually any fault (open circuit, short, loss of power, isolation of fire panel). | Final exits, stair cores, high-risk areas | | **B (Intermediate)** | Must release on fire alarm plus certain critical faults. | Escape doors on main circulation routes | | **C (Basic)** | Must release only on fire alarm. | Lower-risk areas with alternative exits | --- ## Manual Release Devices Every electrically locked escape door must also have a **local manual means of release**, even if the fire alarm system is interfaced. ### Acceptable Devices * **BS EN 54-11 Type B manual call point (MCP)** * Resettable or frangible “break glass” type * Provides direct contacts to drop lock power * **Emergency Door Release (EDR) unit to BS 7273-4 requirements** * Clearly marked green unit labelled *Emergency Door Release* * Provides sustained fail-safe release ### Placement * Adjacent to the door on the escape side * Height approx. 1.4 m, visible and unobstructed * Illuminated where lighting is poor ### Non-Compliant Devices * **Timed auto-reset units** (that re-lock after a delay) * **Push-and-hold-only buttons** (release only while held in) Both fail because the standard requires **sustained release until reset**. --- ## Performance & Timings * Door must release within **3 seconds** of actuation (fire, fault, or manual). * Release devices must be robust and suitable for repeated operation. * Locks must **fail safe** (loss of power releases the door). --- ## Integration with Fire Alarm Systems * Release mechanisms must be controlled by the **fire detection and alarm system (FDAS)**. * Fire alarm interface alone is **not sufficient** — local MCP/EDR still required. * Categories A and B require **fault monitoring** of circuits. --- ## Panic Bars and Exit Hardware **BS EN 1125** (panic bars) and **BS EN 179** (emergency push pads/levers) require that doors open by a **single mechanical action**, regardless of electrical systems. ### Non-Compliant * Maglocks fitted to doors with panic bars or pads: * The panic hardware cannot mechanically override the lock. * Escape depends on electrical release, breaching EN 1125/179. ### Compliant * **Electrified panic hardware** tested and CE-marked to EN 1125/179: * Push bar always mechanically releases the door. * Electronic control is supplementary (e.g. latch retraction for access). * **Mechanical escape doors kept separate from access-controlled doors**. --- ## Maintenance * All doors, release devices, and interfaces must be tested during **routine FDAS maintenance** (BS 5839-1). * MCP/EDR units should be checked regularly for correct operation. * Documentation must record: * Category of actuation per door * Wiring and interfaces * Commissioning/test results --- ## Key Points * BS 7273-4 ensures electrically controlled escape doors always release fail-safe. * Manual local release (green MCP/EDR) is always required. * Auto-reset or push-and-hold devices are non-compliant. * Panic bars must provide a **mechanical override** — maglocks across them are not acceptable. * Compliance requires correct design, installation, testing, and maintenance. --- ## Compliance Quick Reference – Escape Door Locking & Release | Door Setup | Compliant? | Notes | | ------------------------------------------------------------------------------ | --------------- | ----------------------------------------------------------------------------------------- | | **Electrically locked door with fire alarm interface only (no local MCP/EDR)** | ❌ Non-compliant | Fire alarm must not be the *only* release method. Local MCP/EDR always required. | | **Electrically locked door with fire alarm interface + local MCP/EDR** | ✅ Compliant | Meets BS 7273-4 when designed to correct Category (A/B/C). | | **Door with green “push-to-exit” button only (hold-to-run)** | ❌ Non-compliant | Release must be sustained until reset, not dependent on user holding button. | | **Door with timed auto-reset EDR** | ❌ Non-compliant | Locks must stay released until deliberate reset; auto re-locking is unsafe. | | **Maglock on door with panic bar/push pad** | ❌ Non-compliant | Panic hardware must always mechanically override; maglock prevents single-action escape. | | **Electrified panic hardware (EN 1125/179 tested & CE-marked)** | ✅ Compliant | Panic bar always opens door mechanically; electrification is for access control only. | | **Purely mechanical panic bar/push pad (no maglock, no electronics)** | ✅ Compliant | Meets EN 1125/179; always provides free mechanical escape. | | **Electrically held-open fire door with automatic release on alarm** | ✅ Compliant | Provided it releases within 3 seconds and has MCP nearby if also used as an escape route. | --- **Reminder:** Under BS 7273-4, the golden rule is **fail-safe, sustained release with local manual override**. Anything that re-locks automatically or prevents mechanical escape is non-compliant.