SERIES J SELECTION PROCEDURE Service factors Table 1. Service factor fb Daily operation 4 hours 8 hours 16 hours 24 hours Starts per hour <10 10-200 >200 <10 10-200 >200 <10 10-200 >200 <10 10-200 >200 U 0.8 0.9 1.0 0.9 1.0 1.1 1.1 1.2 1.3 1.3 1.4 1.5 Ua 1.1 1.2 1.3 1.1 1.3 1.5 1.3 1.5 1.6 1.4 1.6 1.8 M 1.3 1.4 1.6 1.3 1.6 1.8 1.4 1.7 1.9 1.5 1.8 2.0 H 1.5 1.6 1.8 1.6 1.8 2.0 1.7 1.9 2.1 1.8 2.0 2.2 Load classification Table 2. Description of load classifications Load classifications Description Mass acceleration factor Example Uniform U Machines with uniform load and no shocks Mass acceleration factor < 0.2 Uniform loaded conveyors and elevators. Centrifugal pumps and fans. Agitators and mixers for liquids and semi-liquids without solid particles. Uniform Ua Machines with small shocks and small variations in load Mass acceleration factor < 1 Larger conveyors. Reciprocating pumps with 3 or more cylinders. Agitators and mixers for media with high viscosity and / or solid particles. Machines with moderate shocks and variable load Mass acceleration factor < 3 Larger conveyors. Reciprocating pumps with 3 or more cylinders. Agitators and mixers for media with high viscosity and / or solid particles Machines with very heavy shocks and large masses to be accelerated Mass acceleration factor < 10 Heavy agitators and mixers. Reciprocating pumps with 1 or 2 cylinders. Crushers, mills and presses. Vibrators and shakers Moderate M Heavy H Mass acceleration factor = all external moments of inertia * moment of inertia of driving motor Table 3. Ambient temperature factor ft (All cooling methods) * calculated with reference to the motor speed Table 4. Altitude factor fa (Only for air cooling) Ambient temperature °C Factor ft Altiitude m Factor fa 10°C 15°C 20°C 25°C 30°C 35°C 40°C 45°C 50°C 1.17 1.12 1.06 1.00 0.94 0.88 0.81 0.74 0.66 0 - sea level 750 1500 2250 1.00 0.95 0.90 0.85 Table 5. Ambient air velocity factor fv (Without electric fan) Air velocity V ref m/s Vref < 0.5 0.5 < Vref < 1.4 1.4 < Vref < 3.7 Vref > 3.7 Table 6. Operation time factor fu (All cooling methods) Environment Factor fv Operation Factor ft Small confined space Large indoor space Sheltered outdoor space Outdoor space 0.53 0.71 1.00 1.35 100% 80% 60% 40% 20% 1.00 1.05 1.15 1.35 1.80 6