Use case · Utilities & process motors
Pump, fan & compressor VFDs
Pumps and fans rarely need full speed all day. A VFD replaces throttling valves and DOL slamming — cutting energy and mechanical shock.
The problem
Across Bangladesh, process water, cooling towers, AHUs, compressors and irrigation pumps are still started DOL. The motor takes inrush, pipes hammer, and flow is wasted through a half-closed valve. Textile and factory utility studies in this market commonly report large motor-energy reductions once speed follows demand instead of running at 50 Hz forever.
How this desk works it
We pair motor and drive: kW, FLA, 380–440 V class, and whether the load is variable-torque (pump/fan) or constant-torque (conveyor/compressor). Soft ramp protects couplings and belts. PID is useful on pressure or temperature loops; a simple speed pot is enough for many workshops. We also check protection — MCB/MCCB, overload, and a 24 V supply if a PLC later closes the loop.
What you walk away with
A specified VFD + motor option (or VFD-only retrofit on a healthy motor) with commissioning notes: motor nameplate, cable size, and what not to do (long unterminated motor cables, missing earth, bypassing thermal protection).
Working method
01
Read the motor
kW/HP, FLA, voltage, rpm, connection (star/delta). A photo of the nameplate is enough to start.
02
Name the load
Pump, fan, compressor or conveyor — this decides V/F vs vector and whether you need a braking resistor.
03
Fit protection
Input breaker, motor cable, earth, and keep the motor thermal path intact. VFD is not a substitute for a missing overload on every duty.