Three-Phase Asynchronous Electric Motor Prices: How Power, Poles and Efficiency Class Shape Them

The most honest answer to "How much is a 7.5 kW three-phase motor?" is another question: which 7.5 kW motor? A 4-pole IE3 unit and a 6-pole IE5 unit of the same power come in different frames and sit on different lines of a price list. And over the years the motor runs, its purchase price is often small next to the electricity it consumes.

The quickest way to understand three-phase asynchronous motor prices is to see that most of the choices that move the price are made by the buyer. Below we go through those choices one by one, then put list price next to energy cost with a worked example.

First decision: power

HEM Motor's three-phase squirrel-cage induction motors cover 0.25 to 355 kW. More power means more copper, more lamination steel and a bigger frame, and the price rises accordingly. The most useful thing a buyer can do here is to size power to the real load. A habit of "always going one size up" buys a dearer motor that then runs lightly loaded, with lower efficiency and power factor. To work out the kW a load actually needs, see our guide to motor power calculation for pumps, fans and conveyors.

The overlooked decision: pole count

On a 50 Hz supply, a 2-pole motor runs at about 3000 rpm, 4-pole at about 1500, 6-pole at about 1000 and 8-pole at about 750; the nameplate speed is a little lower because of slip. What matters for price is this: the same power at lower speed means higher torque, and more torque needs a larger magnetic circuit and therefore a larger frame.

Torque is roughly M (Nm) ≈ 9550 × P (kW) / n (rpm). A 7.5 kW motor delivers about 48 Nm at 1500 rpm, about 72 Nm at 1000 rpm and about 96 Nm at 750 rpm. That is why 6- and 8-pole motors are usually in a bigger frame and cost more than a 4-pole motor of the same power.

In practice the question becomes: should the low speed come from the motor itself, or from a 4-pole motor with a belt drive or gearbox? Conveyors, mixers and geared drives often use 6-pole motors. Pumps, fans and general drives mostly use 4-pole motors, which are the most common and usually the easiest to source. 2-pole motors serve compressors, blowers and high-speed pumps.

Efficiency class: purchase price against the power bill

HEM Motor offers its three-phase ranges in three efficiency levels within the same frame system: IE3 Premium, IE4 Super Premium and IE5 Ultra Premium. Higher classes need better lamination steel, more active material and more refined design, which raises the purchase price. In return, the motor produces the same shaft power from less electricity.

To make that concrete, take the catalogue figures for a 50 Hz, 4-pole, 7.5 kW motor: 90.4% for IE3, 92.6% for IE4 and 94.0% for IE5. At full load, input power is roughly 8.30 kW, 8.10 kW and 7.98 kW respectively.

• Choosing IE4 over IE3 saves about 0.20 kW. At 4,000 hours a year that is around 790 kWh; at 6,000 hours, around 1,180 kWh.
• Choosing IE5 over IE3 saves about 0.32 kW. At 4,000 hours a year that is around 1,270 kWh; at 6,000 hours, around 1,910 kWh.

Multiply those kWh by your own electricity tariff and you get a rough idea of how many years the extra cost of a higher class takes to pay back. These figures assume full load, and part-load values will differ. On a single-shift, intermittent drive IE3 is often enough, while on a pump or fan running three shifts IE4 or IE5 can recover the premium much sooner. The payback calculation is covered in more depth in IE3 or IE4: the investment case.

Construction and options: stepping away from standard

List prices assume a standard build. For HEM Motor's three-phase ranges that means a GG20 grey cast iron frame (with an aluminium alternative in selected small ratings), 100% electrolytic copper windings, IP55 protection, class 155 (F) insulation, S1 duty and IC411 surface cooling. Typical departures that change the price:

• Mounting: B5, B14, B34, B35 or vertical V1, V3, V5, V6, V15 instead of foot-mounted B3.
• Protection and insulation: IP56 or IP65, class H insulation.
• Voltage: special voltages beyond 230/400 V or 400/690 V.
• Accessories: PTC or PT100 winding temperature sensors, anti-condensation heater.
• Paint: a non-standard RAL colour or special coating system.
• Site conditions: ambient above +40 °C or altitude above 1000 m may call for derating or the next power size.

How each of these affects a quote is explained in how options and accessories affect motor price.

Reading the price list correctly

HEM Motor's official price list covers IE3 three-phase asynchronous motors. It is dated 24.09.2026, and prices are in Turkish lira, excluding VAT. You will find the current lines and guidance on reading the table on the 2026 electric motor price list page. Keep three points in mind:

1. At the same power, rows differ by pole count, so make sure you are reading the speed you need.
2. The list reflects the standard build; if you need any of the options above, the quoted price will differ from the list.
3. VAT is not included; add it, and freight if applicable, when preparing a budget.

Motors ship from stock in Turkey, and quotes state stock status and lead time in the same reply.

Common mistakes when comparing prices

The most frequent mistake is comparing two three-phase motor quotes on kW and total price alone. One may be 4-pole and the other 6-pole; one IE3 and the other an older IE2 design; one IP55 and the other lower. Under the EU Ecodesign regulation, IE2 motors can no longer be placed on the market across many power ranges, so a cheap quote of that kind deserves a compliance check. Another mistake is picking a lower efficiency class for a motor that will run continuously, then paying the difference back on the electricity bill within a few months.

Conclusion

The price of a three-phase asynchronous motor is largely set by power, pole count, efficiency class and non-standard options, most of which are the buyer's decisions. Sizing power to the load, taking low speed from the right place and matching efficiency class to running hours keep both the list price and the running cost in check. You can browse the models on the asynchronous electric motors page and request a quote with stock and price details for your application.

Frequently Asked Questions

Why does a 6-pole motor cost more than a 4-pole motor of the same power?

The same power at a lower speed means higher torque, and producing that torque needs a larger magnetic circuit and therefore a bigger frame. That is why 6- and 8-pole motors usually come one frame size up and carry a higher price.

Do the price list figures include VAT?

No, the figures in HEM Motor's IE3 price list dated 24.09.2026 are in Turkish lira and exclude VAT. When budgeting, add VAT and, where relevant, freight and the cost of any non-standard options.

Is it worth paying extra for an IE4 or IE5 motor?

That depends on annual running hours and load. On pumps, fans and compressors running long hours at high load, energy savings can recover the premium relatively quickly, while on intermittent drives IE3 is often sufficient.

Why might a quoted price differ from the list price?

The list is based on IE3 motors in the standard build. Requests such as a different mounting arrangement, protection class, voltage, accessories or paint, as well as order quantity, can move the quoted price away from the list.