AC & DC VFD Drives
Variable frequency drives for precise speed and torque control across pumps, fans, conveyors and process lines.
About AC & DC VFD Drives
A variable frequency drive (VFD) rectifies the incoming AC supply to a DC bus, then rebuilds a variable-voltage, variable-frequency output to run a standard induction motor at whatever speed the process needs. Instead of throttling a pump with a valve or a fan with a damper, the motor itself slows down — which on centrifugal loads cuts power draw sharply and removes the current surge of a direct-on-line start.
As a VFD supplier in India, Microtech works with Schneider Electric, Lauritz & Knudsen, Mitsubishi Electric, Siemens, Amtech Electronics and Hitachi drive ranges. Between them these cover compact single-phase units for small machines up to large three-phase drives for main process motors, at 200 V, 400 V and 690 V class supplies. Where a plant is keeping an existing DC motor, we can also supply a DC drive in place of a full motor change.
We select the drive against the actual load — variable or constant torque, starting and overload duty, cable length — rather than just the motor nameplate. Drives are supplied as loose units for your own enclosure, or built into a packaged drive panel at our Varanasi and Lucknow facilities with incomer, reactors, bypass and ventilation wired and tested.
Key specifications
| Power range (LV AC drives, across brands) | 0.1 kW to 2100 kW, depending on brand and series |
|---|---|
| Supply voltage classes | 1-phase 200–240 V; 3-phase 380–480 V; 500–690 V on selected ranges |
| Control modes | V/f control; sensorless vector and PM motor control on selected ranges (e.g. Mitsubishi FR-E800) |
| Overload duty | Heavy-duty (typically 150% for 60 s) and normal/light-duty ratings, per manufacturer datasheet |
| Communication | Modbus RTU built in on many ranges (e.g. SINAMICS V20, Mitsubishi FR-E800 RS-485 models); Ethernet and fieldbus options on selected series |
| Built-in functions | PID control, multi-pump staging, Safe Torque Off (STO) on selected ranges |
| DC drives | Siemens SINAMICS DCM DC converters for retained DC motors |
| Enclosure | IP20/IP21 chassis units; packaged panels built to site requirement |
Features & benefits
- Drive sized against the load curve and duty cycle, not just motor kW
- Six manufacturer ranges, so one supplier can cover small machines and large process motors
- Pump and fan functions such as PID, hibernation and multi-pump control on suitable series
- Safe Torque Off available on selected Amtech, Schneider and other ranges for machine safety circuits
- Line reactors, EMC filters and dU/dt filters specified where cable length or harmonics call for them
- Option of a packaged drive panel with bypass, cooling and control wiring done in-house
- Parameter setup, motor autotune and commissioning support on site
Where it’s used
- Water supply and sewage pumping stations
- HVAC fans, AHUs and cooling towers
- Conveyors and material handling
- Compressors and blowers
- Textile, packaging and process machinery
- Cement, sugar and paper plant process drives
Standards & compliance
AC & DC VFD Drives — FAQs
Which VFD brands do you supply?
We work with Schneider Electric (Altivar), Lauritz & Knudsen (xD series), Mitsubishi Electric (FR-E800 / FR-A800), Siemens (SINAMICS V20 / G120X), Amtech Electronics (Axpert) and Hitachi Hi-Rel drive ranges. If your plant has standardised on one make, we will quote within it.
How do I choose the right size of VFD for my motor?
Start with the motor's full-load current, not just its kW, then match the drive's heavy-duty or normal-duty rating to how hard the load starts and how often it overloads. Long motor cables, high ambient temperature and altitude can all require a larger frame. Share the motor nameplate and a short description of the load and we will size it.
Will a VFD save energy on every motor?
The biggest savings come on centrifugal pumps and fans, where power falls steeply as speed drops. On constant-torque loads such as conveyors the gain is mainly smoother starting and process control rather than large energy savings.
Do you supply DC drives as well?
Yes. Where an existing DC motor is staying in service — on older extruders, winders or mill drives, for example — we can supply a DC drive such as Siemens SINAMICS DCM instead of replacing the motor.
Can you build the VFD into a complete panel?
Yes. We build packaged drive panels at our Varanasi and Lucknow facilities with incomer, line reactor, bypass contactor, cooling fans and your control wiring, tested before dispatch.
