Selection by parameters
Hybrid Power (AC/DC-Solar)

Frequency converters

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What we ship most often as the "workhorse" VFD

We carry over 1,700 VFD models in stock, but most orders close on 4-5 series. Through 2025-2026 our top runners are Veichi AC10 for tight budgets, INVT GD20 on conveyors and compressors, Delta VFD-E for machine tools, Mitsubishi FR-D when the customer already runs Japanese automation, and Schneider ATV310 on sites that need SCADA integration. Tell us the motor's rated current (off the nameplate, in amps). We will pick a model in 5 minutes and ship the same day from our Kyiv warehouse.

A variable frequency drive (VFD, AC inverter) does two jobs. First: soft start without the 5-7x inrush current. We cap it at 1.5x rated. Second: motor speed control from zero up to 600 Hz on the AC10/AC310 series. From this you get 20-60% energy savings on pumps and fans (cubic torque-vs-speed law), mechanical protection from start-up shocks, and accurate pressure or temperature hold via the built-in PID. That is the basic story.

First question we ask: single-phase or three-phase

Domestic 220 V single-phase mains at home or in a small workshop. We pick single-phase units up to 2.2 kW (Veichi AC10-S2 series, INVT GD20-S). If the motor is three-phase but your mains is single-phase, you need a 220 to 380 V converter, and the same AC10-S2 line covers that case. Industrial 380 V three-phase covers 90% of our orders: wider catalog, models from 0.4 to 630 kW. Load type: pump or fan gives variable torque M proportional to n squared (scalar V/f is enough); conveyor, extruder or hoist gives constant torque, so you need vector SVC/FOC.

What else we ask before ordering. One: do you need an EMC filter (yes for residential mains and medical sites). Two: will the drive run from a diesel generator; that needs pre-charge control and a generator sized 1.5-2x the drive load. Three: heavy-start regime (crusher, press), go one power step up. Manufacturer warranty is 12-24 months depending on the series, shipping from our Kyiv warehouse takes 1-3 days. If it is easier, send us the burnt VFD's part number by email or a photo of the motor nameplate, the rest is on us.

How to Choose a Variable Frequency Drive

VFD selection starts with four key parameters:

  1. Motor power and current — the most accurate selection parameter is the motor's rated current in amps. The VFD's rated current must equal or exceed the motor's rated current. Any motor with power below the VFD's rated power can be connected without restrictions. For heavy-start applications (crushers, presses), choose one power step above.
  2. Supply voltage — 1×220V for light-duty applications up to 2.2 kW, 3×380V for industrial installations. To run a three-phase motor from single-phase mains, use a 220V → 380V converter.
  3. Load type — variable torque (pumps, fans — quadratic M∝n²) or constant torque (conveyors, extruders, hoists — M=const).
  4. Control method — scalar (V/f) is sufficient for pumps and ventilation, vector (SVC/FOC) is required for precise positioning and full-torque operation at low frequencies.

Comparison of popular 4–5.5 kW models from different manufacturers:

ModelPowerRated CurrentMax FrequencyControlApplication
Veichi AC104 kW9.5 A600 HzV/fPumps, fans
Veichi AC3104 / 5.5 kW10 A600 HzSVC sensorlessConveyors, extruders
Delta VFD-E5.5 kW13 A600 HzV/f, SVCPumps, machinery
INVT GD204 kW9.5 A400 HzV/f, SVCVentilation, compressors
Danfoss FC514 kW9 A400 HzV/f (AMA)Pumps with PID

Veichi AC10 is the best-selling VFD series in Ukraine for 2025–2026: compact housing, built-in Class C3 EMC filter, frequency range up to 600 Hz for high-speed spindles, and RS-485 (Modbus RTU) interface included as standard. For constant-torque applications requiring 150% torque at 0.5 Hz, choose the Veichi AC310 series with sensorless vector control.

VFD Manufacturers

We partner with manufacturers whose equipment is proven by years of operation at industrial facilities across Ukraine. Each brand serves a distinct market segment — from budget solutions for small businesses to premium systems for critical infrastructure.

  • Veichi Electric — Chastotnik.ua's top seller. Series: AC10 (scalar, 0.4–280 kW), AC70E (single-phase 220V input, 220→380V conversion), AC310 (vector SVC/FOC, 0.75–630 kW). Built-in EMC filter, extended 0–600 Hz frequency range, RS-485 port, user-friendly keypad. Best price-to-performance ratio for most industrial applications.
  • Schneider Electric — French industrial leader. Series: Altivar 310 (compact general-purpose), ATV320 (enhanced with built-in filter and STO), ATV630/ATV930 (heavy industrial processes). Supports Modbus TCP, CANopen, EtherNet/IP, PROFIBUS — seamless integration with SCADA and MES systems. Global service network.
  • Danfoss — Danish HVAC and water supply specialist. Micro Drive FC51 features built-in PID controller, Automatic Motor Adaptation (AMA), and cascade control for up to 4 pumps. FC51 is deployed at waterworks, district heating facilities, and shopping center ventilation systems.
  • Delta Electronics — Taiwanese manufacturer with a comprehensive product range. VFD-EL (economy, fans), VFD-E (universal, 0.4–22 kW), VFD-C2000 (high-performance with STO and auto-tuning). Delta drives operate reliably at up to +50°C without derating — essential for non-air-conditioned enclosures.
  • INVT — Chinese manufacturer with 22 years of experience. GD20 (universal, built-in brake module up to 30 kW), GD200A (heavy industrial duty), GD350A (servo drive). Expansion cards for PG feedback, Modbus, PROFIBUS, Ethernet — flexible adaptation to any automation protocol.
  • ABB — ACS150 (micro drive), ACS310 (pumps/fans with Safe Torque Off), ACS580 (general industrial with Direct Torque Control). Built-in Flying Start for power-loss recovery.
  • Siemens — SINAMICS V20 (basic), G120C (modular with Safety Integrated), G120X (infrastructure-specific). Full TIA Portal integration, PROFINET support.
  • Mitsubishi Electric — FR-D (compact), FR-E (enhanced), FR-A800 (premium with positioning). Japanese reliability, particularly suited for CNC machine tools.

VFDs by Specifications

Quick selection by key parameters:

By power rating: 2.2 kW · 3 kW · 5.5 kW · 7.5 kW · 11 kW · 15 kW · 22 kW

By supply voltage: single-phase 220V · three-phase 380V · 220V → 380V (single → three-phase)

By application: for pumps · for fans · for motors · for single-phase pumps · for generator starting

By control type: vector (SVC/FOC) · scalar (V/f)

Warranty and Support

All variable frequency drives come with a manufacturer warranty of 12 to 24 months. Our engineers will help you select the right VFD for your specific motor and application at no cost: calculate the required power rating for your duty cycle, recommend the optimal series, and advise on startup and protection parameter settings.

Delivery by Nova Poshta across Ukraine: Kyiv, Kharkiv, Odesa, Dnipro, Lviv, Zaporizhzhia, and all locations. Bank transfer with VAT for corporate customers. Consultation and orders: (093) 170-14-25.

Frequently Asked Questions

How do I correctly size a VFD for a motor?

The key parameter is the motor's rated current in amps (from the nameplate), not kilowatts. The VFD's rated current must equal or exceed the motor current. Power in kW is a secondary guide: at the same rating, an older 6-pole motor draws more current than a modern 4-pole. For heavy-start loads (crushers, high-inertia belt conveyors, screw compressors) go one frame size up. For pumps and fans no margin is needed — torque drops quadratically with speed, so the VFD never sees overload during ramp-up.

What is the difference between a VFD and a soft starter?

A soft starter limits inrush current and removes mechanical jerk; once the motor is up to speed it is either bypassed or simply holds the motor at full voltage — it cannot vary speed during operation. A VFD does both smooth starting and speed control from zero to 400–600 Hz, plus PID control of pressure or flow. The choice is straightforward: if motor speed is always constant, use a soft starter (cheaper, smaller cabinet); if any speed adjustment is needed during operation, use a VFD.

Scalar (V/f) or vector (SVC/FOC) control: which one for which load?

Scalar V/f control maintains a fixed voltage-to-frequency ratio and works well for pumps and fans (quadratic torque M∝n²) where speed regulation accuracy under load is not critical. Sensorless vector (SVC) is needed when the motor drives a conveyor, extruder, or hoist: full torque is required from as low as 3–5 Hz with a stiff speed characteristic. Closed-loop FOC with an encoder gives ±0.01% speed accuracy — used in cutting lines, winding, and lifting equipment. Most series in the catalogue (Veichi AC10/AC310, INVT GD20) include both modes in one unit; pure scalar-only models are INVT GD10 and GD200A.

Can I run a three-phase 380 V motor from a single-phase 220 V supply using a VFD?

Yes, with one important note. A single-phase input produces a three-phase output at roughly 220 V, not 380 V — that is a physics constraint, not a device limitation. The motor will deliver approximately 60–70% of its rated power due to the lower voltage. If the motor is wound for star-connection at 220 V it will run at full power. Models in our catalogue with single-phase 220 V input and three-phase output: Veichi AC10-S2, Veichi AC01-S2, INVT GD10-S2, INVT GD20-S. To drive a 380 V three-phase motor from a single-phase supply you need either a step-up transformer or a VFD with a built-in boost stage.

Which VFD brands are available and what warranty is offered?

Over 1,720 models from 14 manufacturers in stock. Largest selections: Danfoss (225 SKUs: VLT FC102/FC202/FC302), Schneider Electric (218: Altivar 12/310/320/610/650/950), Siemens (182: Sinamics G120/G130), Bosch Rexroth (159: EFC/VFC 3610/5610), INVT (138: GD10/GD20/GD200A/GD350), ABB (123: ACS355/ACS580/ACS880), Veichi (123: AC01/AC10/AC310/AC70). By sales volume 2025–2026 Veichi AC10 and AC310 lead — primarily because of their price-to-feature ratio and available Ukrainian service centre. Warranty is 12 months on all series, 24 months on Veichi AC10/AC310 and INVT GD20.

What determines the price of a VFD?

Four factors. Power: price scales roughly linearly with kW. Control type: scalar VFDs cost 15–30% less than vector models at the same power. Features: built-in PLC, Profinet/EtherCAT interface, braking chopper, EMC filter, STO certificate — each option adds to the price. Brand: Japanese and European series (Mitsubishi FR, Siemens G120, Danfoss FC302) cost more than Asian brands at the same rating. Reference prices: budget 1.5 kW — from UAH 3,500; mid-range 5.5 kW — from UAH 9,000; industrial 37 kW with Profinet — from UAH 65,000.

When is a braking resistor or input reactor required?

A braking resistor is needed when the motor brakes frequently or decelerates a high-inertia load: hoists, centrifuges, cutting lines. During regenerative braking the VFD feeds energy back into the DC bus; without a resistor the bus voltage climbs until the OV protection trips. An input reactor (line choke) is recommended for drives 22 kW and above, or when powering from a generator: it reduces capacitor inrush peaks and cuts harmonic THDi from 80–120% down to 30–40%. On sites with sensitive equipment, fit both a reactor and an EMC filter together.

The VFD shows an E.OC fault (overcurrent) — what should I do?

First localize the source. Disconnect the motor from outputs U/V/W and run the drive with no load. If the fault clears, the problem is in the motor or cable (shorted turns, a damaged cable, a damp terminal box). If E.OC persists even without a motor, the output power module (IGBT) is damaged: measure resistance between the DC+/DC- bus terminals and outputs U, V, W — zero resistance confirms a breakdown. A special case for drives above 40 kW: dried-out thermal paste under the heatsink lets the module overheat locally within milliseconds, faster than the temperature sensor can react — inspection and re-pasting fixes it.

Can I set 300 V in the parameters to give the motor more power?

No. A VFD is neither a stabilizer nor a step-up transformer — its output will never exceed the voltage coming in. For 220 V-class drives the motor rated voltage (parameter F02.05 on Veichi) is kept within ~253 V: that is the ceiling of a 230 V +10% supply, above which you risk the DC-bus capacitors. If the motor really lacks torque at low speed, the answer is not «more voltage» but the correct control mode (vector SVC instead of scalar V/f) and torque boost — not inflating the voltage figure.

There is voltage on the motor or panel housing — is it dangerous and how do I remove it?

Yes — stray voltage on the housing is both a safety issue and the reason nearby electronics (scales, controllers, sensors) misbehave. First rule: the motor ground wire must go directly to the VFD PE terminal, not to a shared building bus — otherwise high-frequency PWM currents return through «earth» and induce a potential on the housings. If you measure more than 5 V between neutral «0» and protective earth, the grounding loops must be separated. Ground the shield of signal cables (4-20 mA sensors) at one end only — at the VFD side — otherwise the shield itself becomes an antenna.