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Electrical and electronics · Industrial automation and drives

Variable frequency drive supplier in Bangladesh

Looking for a variable frequency drive supplier in Bangladesh? Send the motor nameplate, the driven machine and the speed range. We source the drive from a verified seller, check its rating, test reports and derating for your panel, and deliver it to your plant.

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Delivered by Roptan

Prefer to deal with suppliers yourself? Post it on the requirement board

Buying variable frequency drives in Bangladesh

A variable frequency drive sets an AC motor's speed and torque by changing the frequency and voltage it feeds the motor. Plants fit drives on centrifugal pumps, fans and blowers to save energy, and on conveyors, cranes and lifts to control speed. Factory drives for three-phase 50 Hz supply sit in the low-voltage class, which IEC 61800-5-1 sets at up to 1 kV AC.

A drive that suits a fan can struggle on a loaded conveyor, and one rated for a cool room loses rating in a hot panel. As your variable frequency drive supplier in Bangladesh, Roptan matches the drive to the torque curve, speed range and cabinet, sources it from a verified seller, checks the papers and delivers.

Kinds of variable frequency drive

Scalar (V/Hz) drives

Scalar control holds the ratio of voltage to frequency. It is usually enough for fans, pumps and simple speed changes, but is less suited to low speed under load, fast speed changes, reversing and positioning.

Vector and direct torque control drives

These control the motor's magnetic flux and torque more precisely. Choose them where torque must be held at low speed, speed changes quickly, the load reverses or positioning matters.

Constant-torque duty drives

Conveyors and positive displacement pumps need full torque at low speed, so the drive is sized for that. The energy saving is much smaller than on a centrifugal pump or fan.

Braking chopper or regenerative drives

A braking chopper and resistor turn braking energy into heat, which suits occasional stops. A regenerative or active front end drive returns that energy to the supply, at a relatively high cost.

How to brief a variable frequency drive supplier in Bangladesh

Motor data: Give kW, full-load current, voltage and speed from the nameplate. When a drive feeds a new motor, ask for an inverter-duty statement or IEC 60034-18-41 qualification of the winding.
Lowest speed and its torque: State the lowest working speed and the torque needed there. A motor cooled by its own shaft fan can overheat running slowly under load unless a separately powered fan is fitted.
Hours at each flow: On a pump or fan the saving depends on how long it runs below full flow, so give the hours at each flow.
Cabinet temperature: Summer maxima in Bangladesh usually reach 38 to 41 °C, and a closed cabinet runs hotter. Drives are derated above their stated ambient, so ask for the model's derating curve.
Dust and corrosive air: In dusty, chemical or coastal plants, ask for conformal-coated boards and a sealed cabinet with filtered forced-air cooling.
Storms and supply swings: Northwester thunderstorms from March to May bring lightning and surges. Specify surge protection and the undervoltage ride-through setting, because a drive does not condition the supply.

Standards and test reports for drives

IEC 61800-5-1:2022: Electrical, thermal, fire and energy safety for drive systems; the European adoption is dated 2023. Ask for the report that names the frame and rating quoted.
IEC 61800-3:2022: EMC requirements and test methods for drives. The 2017 edition is withdrawn in Europe, so ask which edition the report follows and the category the drive meets.
IEC 61800-9-2:2023: Energy efficiency classes (IE and IES) for drive modules and drive systems, so two drives' losses compare on one basis.
IEC 61800-5-2: Functional safety of drives, such as safe torque off, within the IEC 61508 framework. Needed only when your machine needs a safety stop.

What moves the price of a variable frequency drive

Rating and frame: kW, current, overload duty, and a larger frame where cabinet heat forces derating.
Control and communication: vector control, encoder inputs and fieldbus cards on top of a basic scalar drive.
Filters: line reactors, passive or EMC filters, output reactors, and dV/dt or sine-wave filters.
Braking: a chopper and resistor, or a regenerative or active front end design.
Enclosure: a sealed, filtered or air-conditioned cabinet, and coated boards.

Lead times and delivery

Common ratings may be in stock in Dhaka; uncommon ratings and regenerative units are usually imported to order. Sea freight from China to Chattogram has taken about nine days on the direct service that began in 2024, against 20 to 25 days with a transshipment stop, before customs clearance. Roptan confirms dates and any minimum quantity in the quote.

We deliver to your plant anywhere in Bangladesh. The seller or your panel builder wires the drive, enters the motor data and tests it on the load. You receive the parameter list, the safety and EMC reports, the derating curve, the warranty and a VAT invoice (Mushak 6.3). Drives with a Wi-Fi, 4G or Bluetooth module usually need BTRC importer enlistment and a No Objection Certificate before the shipment arrives; a wired-only version avoids this step.

What we check for this order

Reports name the frameWe check that the IEC 61800-5-1 and IEC 61800-3 reports cover the frame and rating quoted, with the edition stated.
Derating at your cabinet heatWe check the maker's derating curve at the cabinet temperature your plant reaches in summer.
Torque at low speedWe check that the drive suits your load type and the torque needed at the lowest speed you gave.
Safety stop dataWhere your machine needs safe torque off, we check that IEC 61800-5-2 data are supplied for the model.

Questions buyers ask

Scalar or vector control: which do we need?

Scalar (V/Hz) control is usually enough for fans, pumps and simple speed changes. Choose vector or direct torque control if the motor must hold torque at low speed, change speed quickly, reverse or hold a position. Tell us the machine and its lowest working speed.

When does a regenerative drive pay?

When braking is frequent and the energy recovered is large, as on cranes, lifts and large inertia loads. Its capital cost is relatively high. For occasional stops, a braking chopper and resistor, which turn the energy into heat, are usually enough.

Will drives cause harmonics on our supply?

They can. A standard drive's diode rectifier draws distorted current. A few small drives on a stiff supply are often acceptable. With many or large drives, ask for line reactors or filters, a multi-pulse rectifier or an active front end, whose line current can be nearly sinusoidal.

Does a drive protect the motor from voltage swings?

No. A drive controls the motor; it does not condition the supply. In May 2025, a factory operator at the Dhaka EPZ said voltage fluctuations were damaging machines. Specify surge protection and set the undervoltage ride-through, and fit a stabiliser if the swings at your board are large.

How soon will I hear back about industrial automation and drives?

Within 48 hours of a complete requirement, with a price and a delivery date. A requirement is complete when it has the quantity, where it is needed and by when.

Who do I deal with?

With Roptan, when Roptan manages the order: we buy from the verified seller and deliver to you. With the supplier directly, when you post on the requirement board and choose a quote yourself.