// Catalogue

Variable Speed Drive Pumps: VSD Hydraulic and Process Pumps

Variable speed drive pumps pair a pump and motor with a drive that changes speed to match demand, instead of running flat out. TSA Hydraulics Engineering supplies them within the Servo & Control family of our Motors & Drives range, for hydraulic and process duties.

Speed is the cheapest control there is. Run a centrifugal pump 20% slower and it draws roughly half the power, because power falls with the cube of speed. On a hydraulic unit, slowing the motor during idle time saves energy and heat too. Tell us the pump, the motor and how the load changes, and we will size a VSD package.

// Buying guide

How a VSD Pump Works

A pressure, flow or level sensor reads what the system needs.
The drive changes the motor’s speed to hold that set point.
The pump delivers only the flow needed, with no throttling or bypass.
At low demand, the motor slows right down or stops.

VSD on Process Pumps

For centrifugal pumps, the affinity laws do the work:

Flow changes in step with speed.
Head changes with speed squared.
Power changes with speed cubed.

That’s why a VSD usually beats a throttling valve or bypass line. It also gives soft starts, which reduce water hammer and wear on pipes and seals. Booster sets, cooling water, and wastewater pumps gain the most.

VSD on Hydraulic Pumps

On a hydraulic power unit, a VSD slows the motor when the machine waits and speeds it up when a function moves. A pressure sensor tells the drive what’s needed. This suits machines with long idle times, and it often cuts oil temperature and noise too.

For faster, more precise control, a servo drive and servo motor may be the better choice.

Before You Fit a VSD

Check that the motor is suitable for drive use, especially if it’s an older motor.
Make sure the motor stays cool at low speed, or add a forced cooling fan.
Respect the pump’s minimum speed. Gear and vane pumps need enough speed to lubricate and seal.
Use shielded motor cable, and keep cable runs within the drive maker’s limits.
Consider harmonics and EMC on larger drives.

Variable Speed Drive Pumps Specifications to Check

Pump type, flow, and pressure or head
Motor power, voltage and frame size
Drive rating and control mode
Minimum and maximum speed
Sensor type and set point
Enclosure rating and mounting location

Why Buy From TSA Hydraulics Engineering

As a variable speed drive pumps supplier, we size the pump, motor and drive as one package around your real duty cycle. You get OEM or equivalent options, and help sourcing variable speed drive pumps replacement parts such as drives, sensors, cooling fans and motor bearings. We tell you upfront whether a part is genuine or an equivalent.

// FAQs