MEDC DB3 Industrial Explosion-Proof Alarm Sounder

Overview

The MEDC DB3 is a high-power explosion-proof sounder for audible alarm and evacuation signalling in hazardous areas, part of the MEDC DB3/DB3B sounder family supplied through Eaton Crouse-Hinds. Certified Ex d and Ex de for gas, and dust-ex-rated for combustible atmospheres, the DB3 produces up to 122 dB at one metre and offers 28 user-selectable tones, making it suitable for fire alarm and general process alarm applications.

Engineering and Design

The sounder housing is moulded in glass reinforced polyester with a high-impact thermoplastic flare, giving a corrosion-free enclosure that withstands offshore and petrochemical service. The unit has an integral volume control, a three-stage design that can be remotely switched, and accepts DC supplies between 12 and 48 V, with EN54-3 compliance maintained between 11 V and 57.6 V absolute. Stainless steel mounting brackets with a ratchet facility are standard, with a swivel bracket option.

Loop wiring follows the MEDC installation manual: the supply is connected through the approved cable glands, and the integral volume control is set during commissioning to the sound level required for the area. The three-stage remote switching allows different tones or volumes to be selected for fire, gas and process alarms from the control panel. When the DB3 is combined with MEDC beacon units in the same loop, the beacon flashtube and the sounder are driven from the same supply and the visual and audible elements are synchronised by the panel.

Key Features

• Ex d / Ex de IIC/IIIC T4/T5/T6 certified for gas and dust zones
• Output up to 122 dB at 1 metre
• 28 tones, user selectable, with integral volume control
• Three-stage unit, remotely switchable
• DC supply 12-48 V; EN54-3 between 11 V and 57.6 V absolute
• GRP enclosure with stainless steel fixing hardware
• Operating temperature range -55 to +85 deg C

Applications

The MEDC DB3 alarm sounder is used in oil and gas terminals, refineries, offshore platforms, chemical plants, power stations and marine installations for fire alarm, gas alarm and general process alarm duties. Installations in Oman and the wider GCC typically combine the DB3 with MEDC beacons and call points in a coordinated alarm system, with tones selected per duty and volume trimmed by the integral control.

The DB3 family is available with a stainless steel mounting bracket with ratchet facility, and the swivel bracket option allows the sounder to be aimed in the required direction on columns and walkways. For offshore and coastal installations the GRP enclosure with stainless hardware provides the corrosion resistance expected in salt-laden air, and the wide supply window of the family covers both 12 V and 24 V plant DC systems. Spare planning for hazardous-area projects normally includes at least one additional sounder per alarm zone.

Ordering the DB3 family requires the sound output, the supply voltage and the number of stages of the alarm system, and the part number options are listed in the MEDC documentation together with the approval status. The same family covers 12 V and 24 V DC plant supplies without separate transformer hardware.

The GRP material resists the maritime atmosphere of coastal plants, and the stainless fixings do not require painting during the service life.

The sounder is certified for the gas and dust zones of the installation, with the marking on the enclosure.

Specifications

Why Seven Star LLC

Seven Star LLC supplies MEDC audible and visual signalling equipment for hazardous-area projects across the Gulf. We verify the Ex certification, supply voltage and tone configuration of each MEDC DB3 alarm sounder against your alarm system design and provide the manufacturer documentation with your order.

Call To Action

Submit a formal inquiry through our RFQ page with the zone classification, supply voltage and loop wiring details of your installation. Our team will confirm the correct MEDC DB3 alarm sounder configuration and respond with a formal quotation.