Choosing the right Wheelock notification appliance for your fire alarm system requires balancing code requirements, system compatibility, and the physical characteristics of the protected space. This guide walks through the key decisions fire alarm contractors, AHJs, and facility managers face when specifying or replacing Wheelock devices.
ADA Compliance and NFPA 72 Requirements
The Americans with Disabilities Act (ADA) mandates visual notification appliances in all areas of public accommodation where audible alarms are provided. NFPA 72 provides the technical performance requirements:
- Wall-mounted strobes must have the bottom of the lens between 80″ and 96″ AFF
- Strobes must flash at a rate of 1 Hz (once per second) and be synchronized when within 55 feet of each other
- Sleeping areas require a minimum 110 cd ceiling-mounted strobe or a 177 cd wall-mounted strobe per ADA hotel room requirements
- Corridors 20 feet wide or less can use a single 15 cd device per 50 linear feet
Wheelock’s Eluxa series and legacy E-series devices are UL 1971 listed for ADA-compliant visible notification.
Candela Requirements by Space Type
The candela (cd) rating determines how far a strobe’s flash is visible. NFPA 72 Table 18.5.4.3.1 specifies minimum candela values based on room size. Wheelock appliances cover the full range:
- 15 cd: Rooms up to 20’ × 20’ (400 sq ft)
- 30 cd: Rooms up to 28’ × 28’ (784 sq ft)
- 75 cd: Rooms up to 46’ × 46’ (2,116 sq ft)
- 110 cd (wall): Rooms up to 54’ × 54’ (2,916 sq ft)
- 135–185 cd (Eluxa): Very large spaces or enhanced coverage
Most Wheelock horn strobes (E70, Eluxa ELHS series) allow field-selectable candela via a jumper or DIP switch, so a single stocked model can serve multiple room sizes.
Temporal-3 vs. Steady Tone
NFPA 72 requires the Temporal-3 (T3) evacuation signal for fire alarm systems — the distinctive three-pulse pattern that repeats every four seconds. Wheelock devices are factory-set or field-programmed for T3 in most fire alarm applications.
When to Use Steady Tone
Steady tone is used for non-fire alert signals — supervisory alerts, security systems, and mass notification tones other than fire evacuation. Some Wheelock MT and NS series devices support multiple tones including steady, pulse, and temporal patterns, making them flexible for multi-signal systems.
NS Series Multi-Tone Capability
The Wheelock NS series supports up to 32 selectable tones, including siren, horn, temporal, and warble. This makes NS devices ideal for industrial facilities, schools, and campuses where different signals indicate different emergency types (fire, lockdown, hazmat, etc.).
System Compatibility: Synchronization
NFPA 72 requires strobe synchronization when two or more strobes are visible simultaneously. Wheelock uses the Wheelock Sync Protocol, supported by the DSM sync module. Legacy two-wire systems require the DSM-12/24 to synchronize multiple devices on a single NAC circuit.
The modern Eluxa series uses built-in synchronization and is backward-compatible with the Wheelock Sync Protocol — no external module required when all devices on the circuit are Eluxa series.
Voltage Compatibility
Most Wheelock notification appliances support 12/24 VDC operation. Always verify:
- The NAC output voltage of your FACP (12V or 24V)
- Whether the circuit is filtered or unfiltered DC (some older Wheelock devices require filtered DC)
- Current draw at the selected candela setting to ensure the NAC circuit is not overloaded
Selecting Between Indoor and Outdoor Models
For locations subject to moisture, humidity, or temperature extremes, Wheelock offers dedicated weatherproof appliance lines. The Eluxa 4X series (NEMA 4X / IP66) is the most robust option for exterior walls and washdown environments. The Eluxa 3R series suits covered outdoor locations like parking structures. Always check the NEMA rating against the environment classification in your project specifications.
Find the Right Wheelock Appliance
Life Safety Consultants stocks the complete line of Wheelock notification appliances — from current Eluxa LED devices to legacy xenon strobes for system maintenance. Our technical staff can help match your replacement device to the original specification. Browse our Wheelock fire alarm parts catalog or call 1-888-557-0558.
