Transmission Systems

          Consider optimising the transmission efficiency of your motors by using synchronous belts instead of V-belts. V-belts can slip and deteriorate efficiency at higher loads.

Consider Getting New Technology

Most motors turn at nearly constant speed. However, much of the time the devices they drive may operate at less than maximum design speed. This speed reduction can be accommodated by an Adjustable Speed Drive (ASD) that varies the shaft speed to the driven load. Slowing a pump or fan in this manner reduces energy consumption much more effectively than allowing the motor to run at constant speed and then restricting or bypassing the flow with a valve or damper.

The newest and most efficient adjustable speed drive is the variable frequency drive (VFD), sometimes called a Variable Speed Drive (VSD). A VFD consists of an electronic power converter that converts constant frequency AC (alternating current) power input into a variable frequency output. The AC motor speed varies in proportion to the drive output frequency.

Applications: The most common applications of ASDs are for pumps and fans to balance flows and meet changing system needs. For example, ASDs can be very cost-effective in retrofit or new construction of HVAC systems. Many HVAC systems were designed with constant flow pumps and fans that are throttled to meet changing operating conditions. ASDs are also useful for loads such as elevators, water and wastewater pumps, boiler fans, cooling towers, cranes and conveyors. The speed range, required precision of speed control, and required torque at lower speeds dictate the type of ASD needed.

Performance/Costs: Savings from ASDs come from reduced load of the fan, pump, or driven device. With fans and pumps, power consumed is proportional to the cube root of shaft speed. If shaft speed is reduced by 10%, flow is reduced by 10%, while power consumption is reduced by 27%. If speed is reduced by 20%, power is reduced by 49%. Compared to throttling as a means of flow control, speed reduction provides dramatic energy savings. Throttling to reduce flow in a fan or pump backs the device up on its operating curve, increasing pressure and often increasing power consumption.