Aritech DP721R Conventional Optical Smoke Detector with Relay

1. Product Name: Aritech DP721R Relay Conventional Optical Smoke Detector

2. Description:

What Is the Aritech DP721R Relay Optical Smoke Detector?

The Aritech DP721R is a conventional optical smoke detector from the Dx700 series with an integrated relay. Its COM/NO/NC contacts allow alarm information to be transmitted to other systems as a volt-free contact. It complies with EN54-7 and is CPR-certified.

Operating Principle

The detector senses smoke using the optical light-scattering principle and raises an alarm at a sensitivity of 10%/m (+1.6%, -3.3%). When an alarm occurs, the integrated relay changes state; the relay contacts can handle loads of 2 A at 30 VDC and 1 A at 120 VAC. The detector continuously monitors sensor sensitivity and operating status, automatically compensating each day for drift caused by background contamination to maintain factory calibration. Once a day, it performs a dynamic, full diagnostic test covering the detection chamber and internal electronics. If sensitivity falls outside the limits or the test fails, the condition is reported to the panel and the yellow fault LED on the detector lights up.

Role in Fire Detection Systems

The DP721R operates like a standard smoke detector on Aritech conventional zones, while its relay output allows an alarm to be transmitted locally to other equipment. This feature simplifies cabling in applications where alarm information needs to be sent to a monitoring input or auxiliary control circuit.

Why Choose It?

• COM/NO/NC relay: Volt-free contacts provide easy monitoring by any system.
• Intelligent self-diagnostics: Daily full diagnostic testing and drift compensation help reduce the risk of false alarms.
• Separate fire and fault LEDs: Alarm and fault conditions can be clearly distinguished on site.
• Wide operating voltage range: The 8.5 to 33 VDC range makes it suitable for most conventional systems.
• Easy maintenance: The optical chamber can be removed and replaced on site; the detector calibrates itself automatically when powered up.

Installation and Commissioning

The DP721R is ceiling-mounted on an Aritech DB702 conventional detector base. The base is supplied with a short-circuit link between the IN and OUT terminals; when the detector is fitted, the link opens, allowing cable continuity to be tested only between the bases. The relay contacts are connected via the COM/NO/NC terminals of the DB702 base. If required, the locking tab on the base can provide additional protection against unauthorised removal. For maintenance, holding a magnet against the detector’s test point starts a sensitivity test; no external measuring instrument or test gas is required.

Technical Specifications

• Status indication: White LED (red during an alarm), yellow LED (test and fault)
• User interface: LEDs
• Compatibility: Aritech conventional zones
• Reset voltage: <2.5 V (max.)
• Reset time: 1 s
• Number of alarm levels: 1
• Connection: Aritech conventional base
• Power supply type: Zone-powered
• Operating voltage: 8.5 to 33 VDC
• Current consumption: 100 µA (quiescent at 24 VDC) / <60 mA (alarm at 24 VDC)
• Detection principle: Optical light scattering
• Monitoring: Alarm threshold, contamination level
• Sensitivity: 10%/m (+1.6%, -3.3%)
• Zone length: Cable-dependent
• Number of outputs: 1
• Output type and rating: Relay (30 VDC at 2 A, 120 VAC at 1 A)
• Programmable: No
• Remote alarm output: None
• Dimensions: 100 x 50 mm (Ø x H)
• Net weight: 115 g
• Colour: Cream white (RAL 9001)
• Mounting type: Ceiling-mounted
• Housing material: Plastic
• Vandal-resistant: No
• Operating temperature: -10 to 55°C
• Storage temperature: -10 to 70°C
• Application temperature (typical): +25°C
• Relative humidity: %0 to %95 (non-condensing)
• Environment: Indoor
• IP rating: IP43
• Compliance: CE, REACH, RoHS 3, WEEE
• Certification: CPR
• Standard: EN54-7

Applications

• Offices and commercial buildings
• Hotel rooms and corridors
• Lift machine rooms and technical rooms
• Schools and public buildings
• Areas where alarm information must be transmitted to another system
• Shops and warehouses

Compatible Products

DP721R is used with the Aritech DB702 standard detector base. It can be installed in the same system as Aritech 1X-F4 and 1X-F8 conventional fire alarm control panels and DP721I, DP721T, DT713-5 and DT713-7 detectors from the same series.

Frequently Asked Questions

What is the relay rating of the DP721R? The relay output is rated at 30 VDC, 2 A, and 120 VAC, 1 A.

Does the DP721R have a remote indicator output? No. This model has a relay output instead of a remote indicator output.

How is the sensitivity test performed? Holding a magnet at the detector's test point starts the self-diagnostic routine; the LED indicates whether servicing is required.

At Narstek, we provide project support for the Aritech DP721R optical smoke detector with relay output and products in the 700 series. Contact us for a quote and technical advice.