AL ATEX H₂ – explosion-proof centrifugal fans for hydrogen atmospheres, up to 11200 m³/h

AL ATEX H₂ – explosion-proof centrifugal fans for hydrogen atmospheres

AL ATEX H₂ centrifugal fans with forward-curved Sirocco-type blades are designed for industrial ventilation in potentially explosive atmospheres containing hydrogen. They are intended for ATEX Zone 1 and comply with Directive 2014/34/EU. The series offers airflow up to 11200 m³/h and pressure up to 1900 Pa.

Main features

• Special ATEX construction for hydrogen-containing atmospheres.
• Equipment category II 2G, suitable for hazardous gas Zone 1.
• ATEX marking: II 2G Ex h IIB + H₂ T4 Gb.
• Type examination document: IMQ 10 ATEX 017 X.
• Applicable standards: EN 14986:2017, EN 1127-1, EN ISO 80079-36 and EN ISO 80079-37.
• Single-inlet centrifugal impeller with forward-curved Sirocco-type blades.
• Volute casing made of folded steel sheet with epoxy-polyester protective coating.
• Galvanized steel impellers for sizes 200–315; welded and painted steel impellers for sizes 355–450.
• Brass inlet.
• Direct-drive construction, execution 4.
• Explosion-proof asynchronous electric motor suitable for hydrogen atmospheres.
• Motor protection IP55, insulation class F, continuous duty S1.
• Motor winding overtemperature protection with PTC thermistors.
• Three-phase speed control by frequency inverter in accordance with manufacturer requirements.
• Conveyed air temperature from −20°C to +60°C; −40°C to +60°C on request.
• 60 Hz versions and temperature classes T5 and T6 available on request.

Fan casing orientations

Standard casing orientation is LG270°. LG and RD discharge directions are available in 45° increments. Orientations 180° and 225° require special factory construction.

Optional accessories

• Round inlet adapter.
• Inlet protection guard.
• Outlet protection guard.

Accessories are not included in the fan type examination document. Their suitability for the intended ATEX installation must be verified separately.

AL ATEX H₂ – technical catalogue (PDF)

AL ATEX H₂ – dimensions

Dimensions in millimetres (mm); weights in kilograms (kg). The dimensional symbols are shown in the drawing below.

Connection and mounting dimensions

Dimension drawing

The drawing illustrates the AL construction. Refer to the tables above for the ATEX H₂ dimensions and weights.

AL ATEX H₂ – technical specifications

Model specifications

P – motor poles; Pm – rated motor power; In – rated current; Qmax – maximum airflow; Pt min – minimum total pressure according to the manufacturer's operating limits.

The manufacturer states a series airflow limit of 11200 m³/h. The highest Qmax in the model table is 10770 m³/h. For models 284 A/B and 314 A/B, Qmax and Pt min are presented for their combined groups; consult the individual performance curves.

AL ATEX H₂ – technical catalogue (PDF)

AL ATEX H₂ – installation and operation

Application and installation environment

AL ATEX H₂ fans are intended for industrial ducted ventilation systems where potentially explosive hydrogen-containing atmospheres may occur. Verify that the ATEX marking II 2G Ex h IIB + H₂ T4 Gb matches the hazardous-area classification, gas composition and temperature requirements.

Ductwork requirements

Forward-curved centrifugal fans must operate connected to a duct system. Additional aerodynamic resistance, such as an adjustment damper, may be required. Limit airflow so that motor current does not exceed the rated value on the motor nameplate.

Casing orientation

The standard orientation is LG270°. LG and RD orientations are available in 45° increments. The 180° and 225° positions require special factory construction.

Mechanical installation

• Secure the fan to a stable support suitable for its weight and operating loads.
• Connect ducts without transferring their weight or mechanical stresses to the fan casing.
• Provide sufficient access for inspection and maintenance.
• Verify that the impeller rotates freely without touching the casing.
• Check the suitability of protective guards and accessories for the ATEX installation.

Electrical connection

Electrical installation must be performed by qualified personnel in accordance with the motor nameplate, manufacturer instructions and hazardous-area requirements. Connect the PTC thermistors to an appropriate protective device. Frequency-inverter operation is permitted only under the manufacturer's specified explosion-protection conditions.

Commissioning

• Check protective earthing, electrical connections and motor protection.
• Verify impeller rotation direction.
• Confirm that airflow and system resistance match the selected fan performance curve.
• Measure motor current and verify compliance with the rated limit.
• Check for abnormal noise, vibration and overheating.

Maintenance

Regularly inspect the impeller, casing, mounting components, motor and protective devices. Before servicing, isolate the electrical supply and prevent unintended restarting. Follow all applicable hazardous-area safety procedures.

AL ATEX H₂ – technical catalogue (PDF)