All-in-one power supply for safety-relevant systems

Building safety is growing in importance, with building automation expanding especially in sensitive environments and in buildings where large numbers of people gather. For both new construction work and when renovating older structures, fire and smoke protection are of key importance. As a result, more and more buildings are being equipped with smart fire protection systems, the key components of which are an automatic fire alarm system and a fire extinguishing system. However, the function of the fire alarm system depends, among other things, on a secure supply of power. A comprehensive system requires a range of unequivocal alarm messages, provided via relay closures, to signal specific internal and external fault conditions. In addition, systems in smart buildings need to support different types of connectivity and offer flexibility in installation and operating modes. In many cases, providing a simple AC/DC power supply and backup system is not enough.

A secure power supply consists of an uninterruptible power supply module and an energy storage device together with the corresponding monitoring, management, and alarm systems. One can assemble the necessary components from different subsystems to create a design optimised for a particular application. This approach, however, is time-consuming and expensive, and the design has to be certified by the applicable regulatory authorities. Important factors that also need to be taken into account for the particular application include physical size, operating temperature range, cooling, and installation.

For integration in fire protection systems or other safety-relevant systems, MEAN WELL has designed its DRS-240 and DRS-480 series: new, smart, all-in-one power supplies. The main feature of these series in the multifunctional integration of an AC/DC power supply, battery charger, DC UPS, and communications monitor, all in a single compact unit. The series are compliant with the safety regulations applicable to fire alarm systems, offer a broad 90-305VAC universal input and battery reverse polarity protection, and fulfil the demands of performance, form factor, installation, and ease of operation. The DRS series can monitor the status of the power supply system in real time and report anomalies in various ways. This keeps troubleshooting time to a minimum, improves the reliability of the system, and reduces maintenance costs.

• Simplified mounting and modular installation: the power supplies in the DRS-240/-480 series are mounted directly onto the widely used DIN rail. This simplifies both installation and maintenance.

• A range of alarm information available at a glance: data communication between the user’s general control system and the emergency power supply can be achieved via a MODBus or CANBus interface.

• The cause of a power failure can be ascertained quickly in different ways: with relay outputs for AC fail, DC OK, low battery, and charger fail, or by reading the status from the unit’s LED display.

• UPS backup function: this supports not only automatic switching to the battery power supply within 10ms of disconnection from the mains supply, but can also be started and operated from the battery via a selectable forced-start function when mains power is unavailable. A further advantage is the automatic load-priority power balancing, which allows surplus power to charge the battery.

• Extremely flexible: the charging characteristics can be adapted to different kinds of battery, either directly via the digital communications interface, the optional “SBP-001 smart programmer” adapter, or manually using the DIP switches (2/3 stage charging characteristics); charging current from 20 to 100% can be set with the potentiometer.

• Small footprint: integrating a range of systems in a single compact housing considerably reduces the space requirements in the switch cabinet and the cost and effort involved in wiring.

• Power Boost Mode: the different models have rated output of 240 or 480W, charging the connected battery and providing energy to the load at the same time. For temporary higher power demands, Power Boost Mode delivers twice the rated current for up to four minutes or three times the rated current for a maximum of four seconds.

For planning the necessary backup times in UPS battery operation, the flexible settings of the DRS allow working with different battery chemistries (lead-acid and lithium battery) and sizes.

The DRS series models are available in 12, 24, 36, and 48VDC output versions. They are suitable for many safety-relevant systems, such as for emergency lighting systems to illuminate buildings in emergency situations. The units are designed to operate in free air convection at temperatures from -30 to +70°C with derating. The reliability (MTBF) of the DRS-240 units is at least 564,700 hours according to Telcordia SR-332 (Bellcore) and at least 73,300 hours according to MIL-HDBK-217F (at 25°C); the corresponding values for the DRS-480 units are only slightly lower.

With an input voltage range from 90 to 305VAC, the devices in the DRS series can be used around the world. They meet the requirements of overvoltage category III and fulfil the ITE safety standards EN/UL 62368-1 and EN 54-4 (fire alarm systems/energy supply systems).
The devices in the DRS-240/DRS-480 series are now in stock at Schukat with a 3-year manufacturer’s warranty.

Schukat electronic offers power supplies from a range of manufacturers, including MEAN WELL, Self Electronics and Recom Power. Schukat stocks around 6000 different types of power supplies and DC/DC converters in production quantities at its automated central warehouse in Monheim am Rhein, Germany.

As a distributor, we provide fast, competent support with direct contact persons, and also offer an expert field service team for on-site problem solving. Customers benefit from rapid processing of enquiries, availability of data sheets and samples, and variable delivery quantities – from samples to series production.

Our technical sales team is here to help when selecting suitable power supply products and for any customer-specific questions you may have.