date:Aug 08, 2013
draulic ram is moving and fluid is therefore flowing, pressure drops, so the drive speeds up the motor to maintain pressure. When the ram is not moving, pressure rises so the drive slows the motor.
Following installation of the variable-speed drive, which took less than a day to complete, the power consumption was measured again and shown to be 5.6 kW. This gave a reduced energy cost of 2,838 a year, a saving of 2,788, with a payback time of just over 17 months.
Chris Sims, Energy and Environm