ENERGY AND COST SAVINGS through automatic extraction capacity co In terms of energy and cost savings, what are the advantages of an extraction unit with connected frequency inverter for automatic extraction capacity control? A frequency inverter adapts the motor speed and the power consumption to the current demand. An extraction unit seldom requires the maximum motor power and with a frequency inverter, no unnecessary energy is consumed for most of the operating time. Components are protected by slowly starting the motor. The service life is increased and maintenance costs are reduced. Noise emissions from the fan are significantly reduced and employee protection improved. The extraction unit runs for a large part of the operating time in a well-regulated partial load range and therefore it consumes noticeably less electricity. For example if the motor speed is reduced by 20% the energy consumption, the energy consumption, decreases over-proportionally by about 5

A fan with a motor power of 22 kW consumes only 11.3 kW (22 kW x 0.8 x 0.8 x 0.8=11.26 kW) at 80% of its speed, thus reducing energy consumption by about 50%. In addition to the over-proportional reduction in power consumption, a frequency inverter takes the individual characteristics of the motors into account and adjusts itself accordingly. The motor is supplied with optimum voltage, current and frequency. This increases efficiency and reduces energy consumption by a further 3-4%. The starting current is reduced, which is several times the rated current. This is important when designing cabling...