Thrush Co. Inc., an industry-leading hydronics company, developed a unique energy-saving water pressure booster system, based on a Baldor variable frequency microdrive and high efficiency motor. Known as the Pressurizer-VS™, the new system provides supplemental pressurization of water supplies, using a preemptive control scheme that employs custom Baldor-developed firmware to regulate output flow and pressure efficiently and accurately. Typical applications include ensuring constant pressure for critical processes such as cooling medical, laboratory and industrial equipment.
All Thrush pressurizers increase water pressure at the point of need and accommodate changes in system flow rates to ensure correct operation of devices such as flush valves, dishwashers, washing machines and shower heads. For its latest Pressurizer-VS product line, Thrush wanted to set a new performance standard by designing a pump control system with an exceptionally narrow pressure deadband, to eliminate temperature fluctuations in mixing valve applications. The company also sought to minimize the power consumption of the system, to help keep users’ running costs as low as possible.
The Pressurizer-VS uses a Thrush TV2g in-line pump closely coupled to a vertically-mounted motor, with an adjacent hydropneumatic pressure tank which enables the system to react instantly water is demanded, and prevents the system cycling during small infrequent demands. The physical layout of the entire system results in a compact footprint, enabling the unit to be fitted in areas too small for conventional systems. The pressurizer is available with a number of different motor and drive options, covering flow rates up to 200 gpm (910 lpm) and pressure boost ranges from 30 to 80 psi. As standard, the system is supplied with a Baldor high efficiency drip proof motor, controlled by a Baldor VS1MD microdrive.
According to Aaron Schipper, Applications Engineer at Thrush, “We chose Baldor’s VS1MD variable frequency drives primarily because of their controllability and efficiency; the drives’ V/Hz control mode enables us to regulate output pressure accurately, and their sleep and wake-up functions help minimize energy consumption. In fact, we received excellent applications support from Baldor, who created customized versions of these functions so that they can be invoked directly by pressure transmitter signals. On the Pressurizer-VS, we pre-pressurize the hydropneumatic tank immediately prior to no-flow shutdown, so that the system is always ready to respond to demand – a unique feature that we call ‘Sleep Boost’ – and this has only been possible thanks to Baldor’s willingness to create custom firmware. We also make use of the drive’s soft-start capabilities, to eliminate any power spikes on start-up.”
Baldor’s V*S microdrives are small, powerful and cost-effective products. The VS1MD model used in this application is a general-purpose drive, available with stock ratings up to 15 HP (11 kW) and with production ratings up to 30 HP (22 kW).
Baldor Electric Company