Woods Fan - Varofoil Axials - Controllable Pitch

ADJUSTABLE PITCH LARGE AEROFOIL

FAN SPECIFICATION

The fan will deliver the volume and pressure specified in the schedule of fan duties when tested to AMCA Standard 210-99. The fan will give the sound levels specified in each octave band to within one standard deviation of 3 dB when tested in accordance with AMCA Standard 300-96.

The fan casing shall be constructed of 3/16” (minimum thickness) mild steel. The motor will be supported by a fabricated steel structure of 3/16” (minimum thickness) mild steel. Drilled flanges will be provided for the attachment of accessories or ductwork.

The finish of the fan assembly shall consist of high-pressure cleaning, application of one coat of primer and one coat of enamel paint. Dry film thickness (DFT) shall be 2.5 mils minimum.

The impeller hub will be cast in high strength heat-treated aluminum alloy, precision-machined and balanced. Blades shall be of aerofoil section cast in 12% Silicon aluminum alloy. Hubs and blades are all X-ray examined before machining.

After assembly the fan is dynamically balanced while on antivibration mountings giving over 90% insulation. The balance standard is in accordance with ISO 2372:1974 Quality Grade C for Class II machines. Maximum vibration velocity will not exceed 0.14 in/sec r.m.s. on 60 Hz supplies over the full pitch angle range, when measured at the fans mounting feet.

The aerodynamic design of the fan is such that the maximum power absorbed by the impeller occurs with the normal working range, i.e. it has a non-overloading characteristic.

The impeller is secured to the motor shaft by a key and keyway. Axial location shall be provided by a collar, or a shoulder, on the drive shaft together with a retaining washer and a screw fitted into a tapped hole in the end of the shaft. The screw is locked in position.

The motor shall have a cast iron frame, pad mounted design and suitable for horizontal through vertical operation. All motors are totally enclosed air over design with a 1.15 service factor. All motor efficiency testing and labeling shall be done in accordance with NEMA MG1-12.53 standard. Insulation shall be Class F with Class B rise. Bearings shall be either ball or cylindrical roller with a L-10 life of 100,000 hours. Grease lubrication lines shall be brought to the outside of the fan casing for motor frame sizes 280 and larger.

Accessories as scheduled on the submittal sheet.