FHF Ex-proof Signalling Hooter dGH 21

The FHF dGH21 and dRGH21 signalling hooters deliver a powerful audible warning signal in hazardous areas and harsh industrial environments. Designed for Group II explosive atmospheres, they provide reliable warning, calling, and signalling functions for offshore, petrochemical, marine, and industrial applications where a distinctive alarm signal is essential.

Furthermore, the hooters generate a sound output of approximately 105 dB(A) at 1 metre, ensuring that alarm signals remain clearly audible in demanding environments. The characteristic hooter sound is specifically designed to stand out from higher-frequency background noise, helping personnel recognise warning signals quickly and effectively.

The dRGH21 version incorporates an integrated call current relay, enabling the unit to respond to incoming telephone ringing signals. As a result, it can be used for both alarm and communication-related signalling applications, reproducing the pulse pattern of the telephone call signal.

To ensure safe operation in hazardous locations, FHF combines a flameproof (Ex d) installation chamber with an increased safety (Ex e) terminal compartment. The flameproof chamber houses the electromagnetic drive system and, on dRGH21 models, the telephone call relay. In addition, the corrosion-resistant GRP housing provides excellent durability while eliminating the need for equipotential bonding thanks to its Protection Class II design.

All DC versions also include an electronic disconnector, significantly extending service life compared to conventional designs.

Key Features

• Explosion-protected signalling hooter
• Designed for warning, calling, and signalling applications
• Suitable for Group II hazardous areas
• Sound output of approximately 105 dB(A) at 1 metre
• Distinctive hooter signal for improved audibility
• Corrosion-free GRP housing
• Lightweight yet highly robust construction
• Suitable for harsh industrial and marine environments
• dRGH21 version with integrated telephone call relay
• No equipotential bonding required
• DC versions include an electronic disconnector for extended service life
• Terminal chamber with Ex e increased safety protection
• Suitable for indoor and outdoor installations
• IP66-rated weatherproof enclosure

Certifications & Protection

• Protection Type:
  • II 2 G Ex de IIC T5, T6 Gb
  • II 2 D Ex tb IIIC T95°C / T80°C Db
• Ingress Protection: IP66
• Protection Class: II