For industrial professionals in major economies such as the UK, it is a day-to-day necessity to navigate motor power specifications. There are two units of measurement that such workers are particularly likely to need to deal with: horsepower (HP) and kilowatts (kW).
The continued widespread use of both these units for industrial applications is a legacy of historical measurement standards and global manufacturing standards.
However, while horsepower and kilowatts often coexist, it is of the utmost importance for industrial professionals in the UK to grasp the difference between them, and to ensure accurate conversions. This, in turn, helps to achieve and maintain operational efficiency, safety, and compliance with modern engineering standards.
The UK Context of Horsepower Versus Kilowatts
The UK mainly operates under the International System of Units (SI). As a consequence, in this part of the world, technical standards, efficiency ratings, and official energy consumption reports typically use kilowatts (kW).
However, even to this day, horsepower (HP) is widely used as a unit of measurement. This is partly attributable to the tendency for many older machines, particularly those imported from the United States or manufactured prior to the full adoption of SI units in certain sectors, to be rated exclusively in HP.
Indeed, the highly globally integrated nature of today’s supply chains is another major factor in this. Motors sourced from other jurisdictions may list HP as the primary rating, thereby requiring engineers to convert to kW for integration into local systems.
3 Reasons Why Accurate Conversion Is So Important for Industry
It might seem a relatively straightforward task to convert HP to kW, and we’ll elaborate on that process in a moment. However, doing so can have significant implications in an industrial setting. Here are some of the reasons why converting accurately is so crucial:
- Compliance And Standardisation
When it comes to adhering to British and European standards, it is often necessary for kW to be used for documentation and safety reporting.
If all motor ratings are correctly documented in the standard unit, this will greatly help to streamline auditing processes and ensure consistency across the given premises’ asset management system.
- Efficiency Calculations and Energy Management
Energy efficiency is a major aspect determining how much it costs to run a factory. Taking every possible action to optimise energy efficiency is a particularly urgent matter in the UK, given how the country continues to suffer from some of the highest industrial energy costs in Europe.
To put themselves in a position to take such action, though, key decision-makers for a given industrial site need to calculate the exact amount of power it is consuming. This necessitates all inputs being in a consistent unit (kW). From here, running costs can be accurately ascertained, and potential energy savings identified.
- Equipment Sizing and Longevity
A miscalculated conversion can easily lead to a motor being installed that is either slightly too powerful or too weak. This can then contribute to operational problems.
In the event of an undersized motor being fitted, for example, there can be a high risk of it overheating and failing prematurely. But an oversized motor, on the other hand, can bring about wasted energy and capital. It is therefore crucial to ensure a correct conversion is performed, so that the motor eventually chosen matches the mechanical load requirements.
How Do You Convert from HP to kW?
Presuming it is imperial horsepower (also sometimes referred to as “mechanical” horsepower) that you need to convert to kilowatts, the formula to use is: kW = HP x 0.7457. This would mean that a 10 HP motor, for instance, has an output of approximately 7.46 kW.
Don’t forget, though, that an online calculator can help make this process even quicker and easier, while also being useful for verifying the accuracy of manual calculations.
So, for example, you may navigate to the website of the electrical component supplier RS, and check output ratings via the HP to kW motor conversion calculator there.
Such free-to-use digital tools can be invaluable in all manner of high-pressure and fast-paced industrial environments, where the complexity of certain projects can drive up the risk of human error when attempting to calculate “by hand”.
This means it can be well worth bookmarking one or several of these trusted HP to kW conversion tools, for when you might next need to use one!
