Rittal DK 7338.221 EFD III is a 1 U 19-inch active aspirating smoke detection system with dual optical detectors, staged pre-alarm and main alarm signalling, and CAN bus connectivity for early fire detection in closed IT and server enclosures.
£4,218.02
The Rittal DK 7338.221 EFD III is a compact early fire detection and aspirating smoke detection system designed specifically for closed, non-accessible server and IT enclosure systems. Installed in a standard 482.6 mm (19-inch) rack and occupying just 1 U, the EFD III provides continuous active monitoring for smoke aerosols to identify developing fires at an early stage.
An integral fan continuously extracts air from the protected enclosure through a pipe system and passes the sampled air across two optical smoke detectors with different sensitivity thresholds. The highly sensitive detector provides a pre-alarm when smoke aerosols are first detected, while the second detector activates the main alarm. Evaluation and control electronics continuously monitor the detectors to ensure correct operation.
The EFD III integrates with professional monitoring infrastructure through floating relay outputs and CAN bus connectivity to the Rittal CMC III monitoring system. Operating from a 100–240 V AC, single-phase, 50/60 Hz supply, the system also provides approximately 4 hours of uninterruptible mains electricity operation, supporting continuous fire monitoring during interruptions to the normal supply.
The Rittal EFD III uses active air sampling rather than relying solely on smoke reaching a passive detector. An integrated fan continuously draws air from the protected enclosure through a pipe system, enabling the two optical detectors to monitor the sampled air for smoke aerosols and provide staged alarm signalling.
The highly sensitive detector provides an early pre-alarm at approximately 0.25%/m light obscuration, while the second optical detector provides the main alarm threshold at approximately 3.5%/m light obscuration. Alarm and fault information can be transmitted through floating contacts or integrated with the Rittal CMC III monitoring platform via CAN bus, supporting centralised supervision of critical IT infrastructure.
| Manufacturer | Rittal |
|---|---|
| Series | EFD III |
| Model | DK 7338.221 |
| Product type | Early fire detection / aspirating smoke detection system |
| Application | Closed, non-accessible enclosure systems |
| Rack mounting | 482.6 mm (19-inch) |
| Rack units | 1 U |
| Width | 482.6 mm |
| Height | 44 mm |
| Depth | 490 mm |
| Rated operating voltage | 100–240 V AC |
| Input phases | Single-phase |
| Frequency | 50/60 Hz |
| Uninterruptible operation | Approx. 4 hours |
| Primary sensor | Optical smoke detector |
| Primary detector sensitivity | Approx. 3.5%/m light obscuration |
| High-sensitivity sensor | Optical smoke detector HS |
| High-sensitivity detector | Approx. 0.25%/m light obscuration |
| Airflow monitoring | Approx. ±10% of total airflow |
| Display | Plain-language display with 6 LEDs |
| Interfaces | Relay outputs, door contact input, CAN, CMC III CAN bus, external alarm, manual call point, tank/fill level, 24 V DC output and USB |
| DET-AC Slave III output | 24 V DC, max. 500 mA |
| Operating temperature | 10–40 °C |
| Storage temperature | -20–65 °C |
| Battery storage temperature | -15–40 °C |
| Relative humidity | Up to 96%, non-condensing |
| Protection rating | IP30 |
| Enclosure material | Sheet steel |
| Enclosure colour | RAL 7035 |
| Front colour | RAL 9005 |
| Certification | VdS |
| Net weight | 14 kg |
| Gross weight | 15 kg |
| Pack quantity | 1 piece |
| EAN | 4028177699328 |
| Customs tariff number | 85311095 |
| ETIM 9 | EC002685 |
| ECLASS 8.0 | 40040104 |
The Rittal DK 7338.221 EFD III is an early fire detection system for closed, non-accessible enclosure systems, using active air sampling and optical smoke detectors to identify smoke aerosols at an early stage.
An integrated fan continuously draws air from the protected enclosure through a pipe system and passes it across two optical smoke detectors. A highly sensitive detector triggers a pre-alarm, while a second detector provides the main alarm threshold.
The EFD III occupies just 1 U and is designed for standard 482.6 mm (19-inch) rack mounting.
Yes. The DK 7338.221 incorporates CAN bus interfaces for integration with Rittal CMC III, as well as floating relay outputs for forwarding alarm and fault signals to higher-level monitoring or control systems.
The EFD III operates from a 100–240 V AC, single-phase, 50/60 Hz supply and provides approximately 4 hours of uninterruptible operation.
Rittal EFD III provides active early smoke detection for critical server and IT enclosure infrastructure, combining dual-threshold optical detection, continuous air sampling, VdS testing and integration with Rittal CMC III monitoring systems.
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2025 has been a big year for LED Controls, and our blog has expanded accordingly. We've covered a wide range of topics across industrial control and factory automation this year. From core technology explainers and new product releases to panel building best practice...