Electric Motors

What is an industrial electric motor?

The asynchronous (induction) electric motor is the most widespread drive in industry: almost 45% of the electricity consumed worldwide goes to electric motors. Its simple construction — a wound stator and a squirrel-cage rotor, with no brushes or magnets — makes it reliable, inexpensive and practically maintenance-free. Motors drive compressors, pumps, fans, conveyors, machine tools — everything that rotates in a plant.

IESCO offers three-phase and single-phase asynchronous motors from 0.37 to 335 kW, with aluminium or cast-iron frames and IE2/IE3 efficiency classes — from stock and to order — as well as motor selection, rewinding and replacement on existing equipment.

Types of electric motors

• Three-phase asynchronous (380 V) — the industrial standard, 0.37–335+ kW; 2-, 4-, 6- and 8-pole versions (3,000 / 1,500 / 1,000 / 750 rpm).
• Single-phase (230 V) — 0.18–3 kW with capacitor start, for workshops and small machines where three-phase power is not available.
• Aluminium frame — 0.37–22 kW (frames 63–180): light, compact, good heat dissipation.
• Cast-iron frame — 0.75–335 kW (frames 80–355): for heavy duty, vibration and aggressive environments.
• Special — brake motors, two-speed, explosion-proof (Ex), inverter-duty with reinforced insulation.

How to select an electric motor

1. Power (kW) and speed (rpm) — the power required at the machine shaft plus a 10–15% reserve; speed is set by the number of poles (2-pole ≈ 2,900, 4-pole ≈ 1,450 rpm).

2. Frame size and mounting — the IEC frame (63…355) defines the shaft height; mounting B3 (foot), B5 (flange) or B35 (both). When replacing an existing motor the frame and shaft diameter must match exactly.

3. Efficiency class — an IE3 motor uses 3–8% less energy than IE1; on a 22 kW motor running 24/7 that is 2,000–4,000 GEL a year. In the EU, IE3 is mandatory for 0.75–1,000 kW motors.

4. Protection and environment — IP55 is the standard for dusty, humid plants; outdoors or near water jets — IP65/IP66; also ambient temperature, altitude and insulation class (F/H).

5. Control — direct-on-line (DOL), star-delta, soft starter or a variable frequency drive. See how each behaves at start-up and how much it saves in our motor starting simulator.

Electric motor + VFD = energy efficiency

The load on fans, pumps and compressors is rarely constant. A frequency inverter matches the motor speed to real demand: reducing speed by 20% cuts a fan's consumption by almost 50% (cube law). Starting current drops from 7×In to 1.2×In, belts and couplings wear less. Calculate the saving for your machine with the VFD savings calculator; all engineering tools are in the Engineer's Corner.

Electric motor brands from IESCO

• VOLT Motor (Turkey) — IE2/IE3 asynchronous motors 0.37–335 kW, aluminium and cast-iron frames, European certification, the best price/quality in the region
• WAT (Turkey) — industrial and brake motors for hoisting and conveyor systems

Together with motors IESCO supplies bearings, Danfoss and Inovance drives, Siemens automation and service: motor selection for existing equipment, replacement, alignment, drive parametrisation.

🎯 A motor burnt out, or you need one for a new machine? 📞 Call us: +995 32 206 01 00 or visit our showroom at 52 Avchala St., Tbilisi.

Frequently asked questions about electric motors

What is the difference between IE2 and IE3 motors?

IE is the efficiency class (IEC 60034-30): an IE3 "premium" motor has 2–4% higher efficiency than IE2 and 5–8% higher than the old IE1. For continuous duty IE3 pays for itself in 1–2 years; for rarely used machines IE2 is sufficient.

Can a standard motor be connected to a VFD?

Yes, most modern IE2/IE3 motors are inverter-capable. Above 55 kW and with long cables, reinforced insulation and an insulated bearing are recommended; for long running at low speed — forced ventilation.

What does frame 132 or 160 mean?

The IEC frame number is the shaft-centre height in millimetres above the mounting surface. The frame defines the foot dimensions, shaft diameter and flange — so when replacing a motor the frame, number of poles and mounting type (B3/B5/B35) must match exactly.

Why do electric motors burn out?

The most common causes: phase loss, voltage imbalance, overload, frequent DOL starts, ventilation blocked by dust, bearing failure. A thermal relay or drive protection and timely bearing replacement solve 80% of these problems.

Which speed should I choose — 1,500 or 3,000 rpm?

It depends on the machine: pumps and fans mostly 1,500 (4-pole), high-speed compressors and centrifuges 3,000 (2-pole), conveyors and mixers 1,000/750 or with a gearbox. At the same power a 4-pole motor is quieter and gives more torque.

Do you have motors in stock?

Yes — common sizes 0.75–45 kW (4-pole, B3/B35) are always in our Tbilisi warehouse; other ratings and special versions within 1–3 weeks. ☎ +995 32 206 01 00, showroom at 52 Avchala St.