The TDF range are twin backward curved centrifugal impellors (Run & Standby) designed for induct installations.

Casings

Robustly constructed from galvanised sheet steel, fitted with proprietry flanges at each end in accordance with DW142.

Impellers

Aerodynamically designed backward curved constructed from aluminium or steel plate depending on size and rotational speed. The rotor of the external rotor motor forms the hub of the impeller. Rotors and impellers are factory matched and statically and dynamically balanced on precision machines according to VDI2060 quality class Q6.3.

Motors

Maintenance free external rotor motors with generously dimensioned sealed for life ball bearings encapsulating a high temperature lubricant. The bearings allow for the fan to be mounted at any angle. Insulation is Class B with the enclosure IP44 according to DIN 40050. The electrical design corresponds to VDE 0530/12.84. The motors are suitable for operation in atmosphere up to 95% RH and ambients up to 40°C. Motors are wound to suit either 240V 50HZ 1PH or 415V 50HZ 3PH electrical supply. All motors are fitted with Hot Spot protection by means of a thermal contact switch incorporated in the motor windings to prevent motor damage due to overloading. As the motors have a special torque-speed characteristic they are ideally suitable for speed control by voltage reduction.

Performance

Performance figures given have been tested using installation Type ‘D’ in accordance with BS848 Part 1 1980 and BS848 Part 2 1985. The aerodynamic performance data being to tolerance Class ‘C’ as recommended by BSI C.A.M.E Scheme, Certification No CM005.

Sound Levels

Sound Levels are measured in a reverberent chamber in accordance with BS848 Part 2. Sound level measurements are taken with the fan operating at 20% of its maxium pressure development. Published dBA figures are sound pressure levels measured at a distance of 3m with spherical sound level propagation. It is included for comparative purposes only and the real sound level experienced will depend on the acoustic characteristics of the area being served.

Quality Assurance

Design and manufacture is in accordance with Quality Assured to BS EN ISO9001