220V and 380V Motors: HP-kW Matching Table for Fast Ordering

The most common confusion when ordering an electric motor comes from power being given sometimes in horsepower (HP) and sometimes in kilowatts (kW). A machine's nameplate may read HP while the supplier's catalogue lists kW; and you still have to clarify whether to order 220V or 380V. In this article we provide the HP-kW matching table together with the rated current for 220V and 380V motors as a practical ordering tool. The goal is to state the correct power once, on the phone or on a quote form, and avoid receiving the wrong motor; and at the end of the page to finalise your power need with us and get a fast quote.

Conversion Between HP and kW: The Basic Logic

Horsepower (HP) and kilowatts (kW) express the same physical quantity, power; only the unit differs. 1 HP corresponds to about 0.746 kW, and 1 kW to about 1.34 HP. So a 5.5 kW motor is roughly 7.5 HP, and a 7.5 kW motor is roughly 10 HP. In the Turkish market motors are usually referred to in kW, while older machine nameplates and some imported equipment use HP. Knowing both units before ordering therefore prevents misunderstanding.

In practice motors are produced in standard kW steps: 0.18 - 0.25 - 0.37 - 0.55 - 0.75 - 1.1 - 1.5 - 2.2 - 3 - 4 - 5.5 - 7.5 - 11 - 15 - 18.5 - 22 kW and up. On the HP side these correspond to about 0.25 - 0.33 - 0.5 - 0.75 - 1 - 1.5 - 2 - 3 - 4 - 5.5 - 7.5 - 10 - 15 - 20 - 25 - 30 HP. We also covered the practical ways to understand power correctly and turn it into an order in our HP or kW: understanding motor power and ordering article.

HP-kW and Rated Current Table for 220V and 380V Motors

The table below gives the most frequently ordered powers with their HP-kW match and approximate full-load (rated) current. The current values are approximate for a 4-pole standard motor and a typical power factor; exact current depends on the motor's efficiency class and pole count. The difference between 220V single-phase and 220V three-phase matters: at the same power a single-phase motor draws significantly more current than a three-phase one. That is why 380V three-phase is preferred at higher powers.

We left the single-phase column blank at 3 kW and above, because single-phase motors are in practice produced up to about 3 kW; beyond that 380V three-phase is required. Our detailed article on single-phase asynchronous motor selection and price is a good starting point for 220V applications. We also compared the single-phase vs three-phase decision end to end in our single-phase or three-phase: 220V and 380V motor selection article.

Why Rated Current Matters: Cable, Fuse and Thermal Selection

Rated current is not just a nameplate value; it determines the correct cable cross-section and the fuse and thermal relay setting. Using the table values, you can plan your supply line and protection equipment in advance. Our article on electric motor protection: thermal, relay and fuse selection shows how to go from rated current to protection settings. We also listed the protection equipment to request together with the motor in our buying protection devices article.

Pole Count and Speed: Same kW, Different Current

The HP-kW match gives the power but does not define the motor on its own. The same kW value can be ordered as 2-pole (about 2800 rpm), 4-pole (about 1400 rpm) or 6-pole (about 900 rpm), and their currents, torques and prices differ. So in addition to power, you also need to state the speed or pole count when ordering. To choose poles by application, our asynchronous motor buying guide: 2, 4, 6 poles article explains which speed suits which job.

In high-speed pump and fan applications, 2-pole 3000 rpm motors stand out; we covered their correct power selection in our IE4 2-pole 3000 rpm motor article. For mid-to-high powers like 11 and 15 kW, we also shared stock and speed combinations in our 11 and 15 kW motor selection article. You can reach all our electric motors guides and our main HEM Motor page for the product range; for efficient options see our high-efficiency electric motors category.

Power Margin (Service Factor) and Correct Sizing

Getting the HP-kW match right is half the order; the other half is knowing how much load you will run the motor at. If a machine draws 4 kW, choosing a 4 kW motor directly is not always ideal. Running the motor slightly below full load, in roughly the 75-90% load band, gives both the highest efficiency and the longest bearing and winding life. That is why leaving a small power margin is common practice in continuously running critical applications. The service factor (SF) is a value showing how much short-term overload the motor can withstand; a motor with SF 1.15 can carry a load 15% above its rated power for a short time.

Both directions of wrong sizing are harmful: a motor chosen too small is continuously overloaded, overheats and fails early; a motor chosen too large means both extra cost and a low power factor at low load. We addressed at what load it is right to run the motor in our motor load ratio and correct sizing article, and the importance of the service factor in purchasing in our service factor and overload capacity in IE3 motors article. Sharing the machine''s real power requirement in your order lets us determine the right power together.

Efficiency Class and Regulation: The Step After the HP-kW Table

After clarifying the power in kW, the next step is the efficiency class. In Turkish and EU regulation, IE3 and IE4 efficiency classes are mandatory in certain power ranges. As of 2021, at least IE3 class is required for three-phase motors in the 0.75-1000 kW range; and an IE4 requirement has come into force for certain motors in the 75-200 kW range. So after determining your power from the HP-kW table, you also need to check which efficiency class that power requires. This matters for both legal compliance and long-term energy cost.

We explained which power requires which efficiency class, with dates and power thresholds, in our IE3 and IE4 efficiency mandate article. We compared whether you should choose IE3 or IE4 from an investment and payback angle in our IE3 vs IE4 electric motor investment article. When the right power and the right efficiency class are determined together, you both comply with regulation and lower your operating cost.

A Practical Checklist for Fast Ordering

To turn the HP-kW table into an ordering tool, you can follow a short checklist. First, determine the power of your machine or old motor in HP or kW and confirm the equivalent in the other unit from the table. Second, clarify the voltage: does your facility have 220V single-phase or 380V three-phase supply? Third, determine the speed or pole count; the same kW is a different motor at different speeds. Fourth, add the mounting type (foot B3, flange B5/B14, combined B35) and, if needed, the shaft diameter.

Once these four pieces of information are clear, you can read the rated current from the table and plan your cabling and protection equipment in advance. To prevent receiving the wrong motor, we recommend doing pre-order nameplate matching; we explained this step by step in our avoid wrong motor delivery article. We shared whether it will be delivery from stock or a production order, and the lead times, in our from stock or production order article, so you can plan your schedule from the start.

From Rated Current to Cable Cross-Section: A Practical Example

The rated current column next to the HP-kW table is not just for information; it is the basis of your installation planning. Let us explain with an example: the rated current of a 7.5 kW, 380V three-phase, 4-pole motor is about 15 A. Based on this current, you determine the supply cable cross-section, the motor protection switch and the thermal relay setting. The thermal relay is usually set to the motor''s rated current; too low a setting causes the motor to stop unnecessarily, while too high a setting fails to provide protection. The cable cross-section is also chosen by the current, line length and laying method.

On the single-phase side, the same power draws higher current, so the cable and protection grow accordingly; this is one of the practical reasons why a single-phase motor stays within a certain power limit. At the moment of starting, the motor draws several times its rated current; that is why the starting current is also considered in fuse and protection selection. This starting current carries separate importance in facilities running on a generator; our motor selection on generator-run sites article addresses this topic.

Knowing the correct rated current lets you assess, before ordering, whether your electrical infrastructure is adequate. If your existing line cannot carry the motor you chose, you must either reinforce the line or choose a different power-voltage combination. We calculated how many kW a generator of a given kVA can carry in our how many kW a kVA generator can carry article. If you send us the power, voltage and speed information, we also share the rated current and recommended protection values with the quote, so you plan the motor and the installation in harmony from the start.

Frequently Asked Questions

How many kW is 1 HP?

1 HP corresponds to about 0.746 kW. Conversely, 1 kW is about 1.34 HP. In practice a 5.5 kW motor is about 7.5 HP, a 7.5 kW motor about 10 HP, and an 11 kW motor about 15 HP. If your nameplate reads HP, you can find the kW equivalent with these factors and finalise your order, or send it to us to confirm if you are unsure.

What is the difference between buying the same kW motor in 220V single-phase vs 380V three-phase?

At the same power, a 380V three-phase motor draws lower current, runs more efficiently and is the only option above about 3 kW. A 220V single-phase motor is practical for relatively low-power applications where only single-phase supply is available. We can determine the right voltage together based on your facility's supply type and power.

What information should I provide when ordering?

For a fast and accurate quote, the power (kW or HP), voltage (220V single-phase, 380V three-phase), speed or pole count, mounting type (foot/flange) and, if available, the existing motor's nameplate data are enough. Instead of a list price, we use this to identify the motor that fits your need and prepare a fast quote.

Get a Quote

Tell us the correct power in HP or kW, and we will offer the suitable 220V or 380V motor with fast delivery options. To eliminate the risk of the wrong motor, call us now at +90 (532) 345 49 86 or send your request via our contact page.