- Fan Type
The fan shall be direct drive and belt drive. Fan wheels are centrifugal, backward inclined, and constructed of aluminum. The inlet Venturi shall have round curved section to smoothly transit the air to the wheel cone. The wheel shall be statically and dynamically balanced to Level G2.5 as per AMCA 204 standard.
- Quality Standards
The fan shall be tested in accordance with AMCA Standard 210 and 300 and AMCA licensed according to AMCA Publication 211 and 311 for sound and air performance. And each fan shall be affixed with AMCA sound and air performance seal. The manufacturer must own the production license for industrial products and ISO9001 quality system authentication.
- Fan Structure
The fan housing shall be constructed of steel, the thickness shall be adequate to support drive and motor. The scroll shall be fully welded and shall be provided an access door for removing possible debris inside of the scroll. The fan shall be installed on a stable level platform via vibration isolators. Any pre-embedded fixing devices shall not be required.
Fan surface shall be polished and cleaned up to remove particulates, welding slag, burrs, sharp edge, iron, oil, then epoxy coating [options: colour changes are available], fan surface shall be free of sags, wrinkle, blisters, exposed metal or peeling after coating.
- Transmission Device (Only for belt drive type)
Shaft: Fan shaft shall be heat treated through soaking furnace to the hardness level of HB370, and the surface shall be hard film corrosion treated. The fan shaft shall be balanced together with the wheel, and the shaft design speed shall at least exceed 25% of the maximum fan operation speed.
Pulleys: Fan pulleys shall be sized for a minimum of 150% of driven power. Pulleys shall be cast iron, keyed and securely attached to the wheel and motor shaft. Motor pulleys shall be adjustable for final system balancing. Conical (QD) type bushing shall be equipped for easy removal of the pulleys.
Bearing: Two bearings shall be used to support fan shaft to avoid wheel vibration directly applied to motor. The bearings shall be selected for a minimum (L－10) life in excess of 80,000 hours at maximum cataloged operating speed. Bearing type shall be permanently sealed, lubricable pillow block metal ball bearings.
Drive support: Drives shall be supported by powder coated (corrosion resistant) heavy gauge steel, and mounted on vibration isolators. The belt tension shall be adjusted through motor support plate, the design shall make sure the fan shaft and motor shaft always parallel.
Protection cover: A shaft/bearing cover and a belt cover shall be provided as standard configuration for indoor application. If the fan is outdoor installed, the motor and other drive parts shall be covered by weatherhood to assure lasting durability.
Motor shall be carefully matched to the fan load, IP54, and insulation class F. Motor bearings shall be re-lubricable ball type. Motor and drives shall be out of the air stream to avoid grease or dirt accumulation.
- Explosion-proof Structure (Only for explosion-proof type)
Fan shall conform to Spark B explosion-proof structure according to AMCA99 Standard. The wheel and the inlet shall be constructed of aluminum and the motor shall adopt explosion-proof type. The whole fan should own CNEX certification and the manufacturer must own the production license for anti-explosion electric products.
Permanently fixed aluminum nameplate shall be fixed on fan body clearly display fan mark, product model and serial number (i.e.: unique ID for each fan), so that the customer can use this number to find out the parts used.