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There are two power values most in demand in industry: 5.5 kW and 7.5 kW. Because these powers correspond to a wide range of applications, from conveyor and belt drives to pump and fan applications, from compressors to geared systems, IE3 efficiency class 5.5 and 7.5 kW motors have strategic importance in terms of supply. This guide clearly explains, for procurement managers, machine manufacturers and plant maintenance teams, the pole/speed options these two powers come in, the stock and delivery advantage, the correct selection criteria, and the fast quotation process. Instead of giving a fixed list price, our goal is to supply the exactly suitable motor for your need in the shortest time.
Why Are 5.5 and 7.5 kW the Most Sought-After Powers?
These two power values correspond to the power band that the vast majority of mid-segment industrial machines require. While very small powers (0.75-2.2 kW) are used for light applications and very large powers (30 kW and above) for special projects, 5.5 and 7.5 kW appear in many standard machines that we can describe as "medium load". This prevalence both increases demand and enables these powers to be supplied quickly from stock.
The IE3 class is now the standard choice at these powers, because Turkish and EU regulations require at least the IE3 efficiency class for three-phase motors in this power band. We discuss in detail at which power and from which date the IE3 and IE4 mandate applies in our IE3 and IE4 efficiency mandate article.
Pole and Speed Options for 5.5 and 7.5 kW IE3 Motors
The same power value is offered at different speeds with different pole counts. The most common options for 5.5 and 7.5 kW motors are as follows:
2 Pole (approx. 2900-3000 rpm)
Preferred for pump, fan and compressor applications requiring high speed. Due to slip, 2-pole motors run at around 2900 rpm. They are common in high-pressure booster and centrifugal pumps.
4 Pole (approx. 1450-1500 rpm)
This is the most sought-after speed option. The vast majority of conveyors, geared systems, general industrial drives and balanced pump applications run with 4-pole (1500 rpm) motors. This is usually the option most quickly available from stock.
6 Pole (approx. 950-1000 rpm)
Preferred in mixer, mill and heavy-start applications requiring higher torque and lower speed. At the same power, a lower speed means higher torque. We detail the effect of pole selection on the application in our 2, 4, 6 pole motor selection article.
Frame Size and Connection Type: Correct Selection From Stock
5.5 and 7.5 kW motors are produced in different IEC frame sizes depending on the pole count. For example, while 4-pole 5.5 kW is generally around frame 132 and 7.5 kW around frame 132, the 2-pole versions may be in a smaller frame. The frame size determines the motor's shaft height, shaft diameter and foot/flange dimensions; therefore, when replacing a motor, not only the power but also the frame and connection type must match.
In terms of connection type, these motors are offered with options such as B3 (foot-mounted), B5 (large flange), and B35 (foot + flange). For motors to be connected to a gearbox, the flanged (B5/B14) type is preferred, while for direct floor mounting the foot-mounted (B3) type is preferred. You can find connection type selection in our B5 vs B14 connection type selection article, and the mounting options on our electric motor mounting types page.
Cast Iron or Aluminium Body?
At 5.5 and 7.5 kW, both aluminium and cast iron body options are available. The cast iron body is more durable for heavy duty, high-vibration and harsh environments and is superior against mechanical impact. The aluminium body is lighter and more compact, preferred especially in gearbox assemblies and light applications. The motors in our catalogue range are produced with 100% copper winding and IP55 protection class.
Choosing the right body material according to your environmental conditions affects both the lifetime and the total cost. We discuss this decision in detail in our cast iron or aluminium body article. To review our efficient motor range, you can look at our IE3 electric motor and high-efficiency electric motors pages.
Typical Applications for 5.5 and 7.5 kW IE3 Motors
To understand why these two powers are so common, it is enough to look at their typical applications. 5.5 kW motors are widely used in medium-sized conveyor belts, small-to-medium compressors, booster groups, ventilation fans, woodworking machines, small grinders and geared drives. 7.5 kW, one step above, appears in more powerful conveyors, screw compressors, centrifugal pumps, blowers, mixers and mill drives.
Most of these applications are in continuous duty (S1); that is, the motor runs under a constant load for a long time. Selecting the correct power-speed combination for continuously running plants directly affects efficiency. For conveyor applications, our high-efficiency electric motors range, and for pump applications, the correct selection criteria can be found in our centrifugal pump motor selection article. In use with a gearbox, matching the right motor with worm gear reducers is important.
The Return of IE3 Efficiency at These Powers
In motors that run long hours a day, such as 5.5 and 7.5 kW, the efficiency class directly affects the annual energy cost. An IE3 class motor runs with significantly lower losses than its old IE1/IE2 counterparts; in a continuously running application, this difference translates into meaningful energy savings over the year. Moreover, since IE3 is now mandatory by regulation in this power band, it is also the standard option in purchasing.
We discuss the difference between IE3 and the previous class, and why old-stock IE2 motors no longer make sense, in our IE3 vs IE2 motor difference article. You can review the decision of whether to stay with IE3 or move to IE4 in our stay with IE3 or move to IE4 article.
Stock and Delivery Advantage: Why Does Speed Matter?
Because 5.5 and 7.5 kW IE3 motors are the most sought-after powers, the common pole and connection types of these powers are usually in stock. This is a great advantage especially when an urgent motor need arises due to a failure: for a plant whose production line is down, being able to deliver the motor the same day or in a very short time directly reduces the downtime cost. We cover the process of finding an emergency replacement motor in our conveyor belt motor emergency replacement article.
Knowing the difference between delivery from stock and a production order helps you plan your project correctly. Standard 5.5 and 7.5 kW IE3 motors are mostly available from stock, while variations such as special frame, special speed or explosion-proof may have a lead time. You can review this topic in our delivery from stock or production order article.
The Right Quote Instead of a Price: How Is It Priced?
The price of a 5.5 or 7.5 kW IE3 motor varies depending on many factors such as the pole count, body material (cast iron/aluminium), connection type, brand, stock status and order quantity. Therefore, instead of giving a fixed list price, we prefer to offer the correct quote specific to your need. For an accurate and fast price, it is enough to tell us the motor's power, speed/pole, connection type and quantity.
You can find all the factors affecting the price in our factors affecting electric motor prices article, and the ways to reduce cost in wholesale purchasing in our electric motor wholesale purchasing article.
Exact Matching When Replacing an Existing Motor
When replacing a failed 5.5 or 7.5 kW motor, the safest method is to match the information on the existing motor's nameplate exactly. The power (kW), speed (rpm) or pole count, voltage, frequency, connection type (B3/B5/B35), frame size and shaft diameter on the nameplate ensure that the new motor is mechanically and electrically compatible with the old one. Simply saying "5.5 kW motor" can lead to a motor arriving in the wrong speed or wrong connection type.
Especially in motors connected directly to a gearbox or pump, the flange and shaft compatibility is critical; even a millimetre of difference can cause a mounting problem. Therefore, taking a photo of the nameplate and sending it to us is the fastest and safest method. We detail the exact replacement process in our old brand motor direct replacement article, and nameplate matching in our avoid the wrong motor delivery article.
Checklist for Choosing the Right 5.5/7.5 kW IE3 Motor
Clarifying the following information before ordering ensures you get the right motor the first time: power (5.5 or 7.5 kW), pole/speed (2/4/6 pole), connection type (B3/B5/B35), body material (cast iron/aluminium), shaft diameter, duty type, and any special requirements (explosion-proof, brake, etc.). If you are replacing an existing motor, a photo of the nameplate is the fastest method. You can find duty type selection in our duty type (S1-S6) selection article, and the IE3 stock guide in our IE3 electric motor stock guide article. You can visit our products page for our entire product range.
Frequently Asked Questions
Can 5.5 and 7.5 kW IE3 motors be delivered from stock?
Yes. Because these two powers are the most sought-after values, they can usually be delivered quickly from stock in common pole (especially 4 pole/1500 rpm) and connection types. Variations such as special frame, speed or explosion-proof may have a lead time; just contact us for an exact delivery time.
How much does a 5.5 kW motor cost?
Instead of giving a fixed list price, we offer a quote specific to your need, because the price varies according to the pole count, body material, connection type and quantity. If you tell us the motor's power, speed, connection type and quantity, we will quickly provide you with the correct quote.
Should I buy a 2-pole or 4-pole 5.5 kW motor?
This depends on the speed your application requires. For pumps and fans requiring high speed, 2 pole (approx. 2900 rpm); for conveyors, geared systems and general drives, 4 pole (approx. 1450 rpm) is preferred. If you tell us your application, we can determine the right pole together.
Get a Quote
We supply 5.5 and 7.5 kW IE3 motors, the most sought-after powers, in the pole, body and connection type suitable for your need, from stock or with fast supply. To get the right motor in the shortest time, request a quote from our expert team: call +90 (532) 345 49 86 or send your request through our contact page.
