What information does EMPE need to manufacture a custom electric motor

The conversation starts where you are, not where you think you should be.

Requesting a custom electric motor does not begin with a phrase such as "I need a special motor". That is fine for opening the conversation, but to manufacture a truly useful solution, it is necessary to get down to the technical details: application, available space, shaft, environmental conditions, type of service, temperature, connection, validation and integration requirements.
The better defined the need, the easier it is to develop a motor that is coherent with the real working conditions. And in industry, that makes the difference between a solution that fits from day one and an adaptation that ends up generating incidents, overheating, vibrations or subsequent modifications.
That is why, when a company contacts EMPE to explore a custom electric motor, the first phase is not manufacturing. It is understanding what that motor must do, where it will work and what technical constraints cannot be ignored.

1. The Real Application of the Motor

The first important piece of information is the application. Indicating power, voltage or speed alone is not sufficient. It is necessary to know what function the motor will have within the assembly.
A motor may be intended for a pump, a ventilation system, an industrial machine, equipment with frequent starts, or an application where continuity of service is critical. Each case conditions the mechanical, electrical and thermal design.
To prepare a technical enquiry, it is advisable to specify:
  1. Type of machine or installation where it will be fitted.
  2. Function of the motor within the assembly.
  3. Load conditions.
  4. Anticipated operating hours.
  5. Whether it will operate continuously, intermittently or with variable cycles.
  6. Level of process demand.
This point is key because the manufacture of custom electric motors must respond to a specific need, not a generic customisation.
In EMPE's article on custom industrial electric motors, it is already explained that parameters such as the shaft, insulation, protection or duty rating directly condition the real-world performance of the equipment. This new approach goes one step earlier: what data must the client provide in order to define those parameters properly.

2. Electrical and Operating Data

The electrical aspects and the dynamic behaviour of the motor must be clearly established from the outset. This covers data such as voltage, frequency, power, speed, type of supply, possible connection requirements… and the required motor torque, which is one of the most critical parameters and, at the same time, one of the most frequently omitted in an initial enquiry.

Why Motor Torque Is So Important

The power of an electric motor follows a direct relationship: Power = Torque × Speed. This means that two motors with the same rated power can transmit very different torques depending on the speed at which they operate, and vice versa.
A motor for a fan and a motor for a conveyor belt may have the same rated power, but their torque requirements are completely different. The fan primarily needs speed with a relatively low torque; the conveyor belt requires high torque from start-up in order to move the load from the very first moment.
Overlooking this difference can lead to selecting a motor that, on paper, appears correct but in practice does not perform well in the application: it starts with difficulty, overheats, loses speed under load or simply cannot drive the system under real operating conditions.
For this reason, when specifying a custom motor, it is important to detail:
  1. Stand-by or rest torque: the minimum torque the motor must maintain when it is on stand-by or stationary but with load present. In some applications this is a critical figure to prevent the system from moving back or drifting.
  2. Nominal operating torque: the torque required during the normal duty cycle, at the intended speed.
  3. Starting torque: in applications with load from the outset (conveyors, hoists, drive systems), the motor must be capable of overcoming inertia and initial resistance before reaching running speed.
  4. Torque peaks: if the application generates intermittent overloads, these must be specified to ensure the motor can absorb them without damage.
Recommended information for this section:
  1. Required power.
  2. Supply voltage.
  3. Frequency.
  4. Rated speed.
  5. Required torque at rest and during operation.
  6. Starting torque and anticipated peaks.
  7. Type of current.
  8. Starting method.
  9. Whether the motor needs to operate with a variable frequency drive.
  10. Connection or terminal box requirements.
If the motor is to be integrated into an existing installation, it is also important to indicate the limitations of the current electrical system. The problem sometimes lies not only in the motor itself, but in how it must coexist with the rest of the installation.

3. Available Dimensions and Mechanical Integration

One of the most common reasons for manufacturing a custom electric motor is that the available space does not permit the use of a standard configuration.
For this reason, before manufacturing, it is important to know the maximum dimensions, the mounting position, the fixing points and any physical constraints of the machine or installation.
Useful data:
  1. Drawings of the available space.
  2. Maximum permitted dimensions.
  3. Mounting position.
  4. Type of fixing.
  5. Access restrictions.
  6. Maintenance requirements.
  7. Compatibility with existing components.
A motor may be perfectly calculated from an electrical standpoint and still fail in practice if it does not fit mechanically. And that is where workshop improvisation begins. Improvisation is best left to a science fair; on the plant floor, the less of it, the better.

4. Shaft, Coupling and Transmission

The shaft is one of the most sensitive elements in a custom motor. Its geometry, length, diameter, tolerances and coupling system directly influence torque transmission, alignment and the durability of the assembly.
To define it correctly, it is advisable to provide:
  1. Drawing of the required shaft, if available.
  2. Type of coupling.
  3. Required diameter and length.
  4. Keyways, threads or other specific geometries.
  5. Anticipated radial or axial loads.
  6. Mounting conditions.
  7. Special machining requirements.
EMPE has already addressed the importance of custom shafts and in-house machining as part of motor precision and reliability. This point is particularly important when the motor must be integrated into an existing machine or when the coupling conditions the performance of the system.

5. Environmental Conditions

The working environment directly affects the design of the motor. Operating in a dry, clean environment is very different from an application involving humidity, dust, water, dirt, high temperatures or aggressive agents.
For this reason, the enquiry should include information on:
  1. Ambient temperature.
  2. Presence of dust.
  3. Humidity or splashing.
  4. Possible exposure to water.
  5. Indoor or outdoor environment.
  6. Chemical or corrosive agents.
  7. Sealing requirements.
  8. Cleaning or washdown conditions.
The definition of the protection rating must reflect those real conditions. The IEC 60529 standard is used to classify the degree of protection of enclosures against the ingress of dust and liquids, by means of the well-known IP codes.
In industrial applications, selecting the correct level of protection is not a minor detail. Insufficient protection can compromise the reliability of the motor; over-specified protection can increase the cost of the project without providing any real technical benefit.

6. Duty Rating and Operating Cycle

A motor operating continuously does not have the same requirements as one subjected to frequent starts, stops, variable loads or intensive cycles.
For this reason, before manufacturing a custom electric motor, it is important to define how it will operate.
Recommended information:
  1. Continuous or intermittent operation.
  2. Approximate number of starts per hour.
  3. Duration of cycles.
  4. Operating time and rest time.
  5. Variable or constant loads.
  6. Possible overloads.
  7. Need for braking or reversing.
The IEC 60034-1 standard is an international reference for rotating electrical machines and sets out duty types to describe how a motor operates according to its load and operating cycle.
This information is fundamental because the duty rating affects thermal sizing, service life and material selection.

7. Temperature, Insulation and Thermal Margin

Temperature is one of the factors that most significantly influences the service life of an electric motor. For this reason, a technical enquiry should not focus solely on power, but also on how the thermal behaviour of the motor will be managed.
It is advisable to indicate:
  1. Maximum ambient temperature.
  2. Ventilation conditions.
  3. Anticipated load.
  4. Operating time.
  5. Possible operating peaks.
  6. Insulation requirements.
  7. Need for additional thermal margin.
The insulation class indicates the capacity of the insulation system to withstand temperature over the service life of the motor. Technical documentation for motors uses classes such as B, F or H, each associated with different maximum thermal levels of the insulation system.
In practice, this directly affects reliability. A motor operating too close to its thermal limit may function initially, but will be at greater risk of degradation, loss of performance or premature failure.

8. Efficiency and Performance Requirements

When a custom motor is requested, it is also important to establish whether there are specific objectives regarding efficiency, energy consumption or performance.
Not all projects seek the same outcome. Some prioritise mechanical integration. Others need to reduce energy consumption. Others seek reliability in continuous service. And others require a combination of all of the above.
Useful data:
  1. Performance target.
  2. Expected energy consumption.
  3. Real load conditions.
  4. Need to operate with a variable frequency drive.
  5. Priority between initial cost, efficiency and durability.
  6. Validation or testing requirements.
EMPE has already addressed in its blog the importance of energy-efficient electric motors and validation through its test facility, particularly for verifying performance, efficiency and temperature under different load conditions.

9. Testing or Validation Requirements

In demanding applications, manufacturing the motor is not sufficient on its own. It may be necessary to validate its behaviour prior to delivery.
In such cases, it is advisable to specify from the outset what must be verified:
  1. Performance.
  2. Temperature.
  3. Energy consumption.
  4. Behaviour under load.
  5. Starting.
  6. Vibration.
  7. Compatibility with the application.
  8. Documentation requirements.
Validation helps to reduce uncertainty and allows confirmation that the motor responds to its intended use before entering real-world operation.

10. Documentary Information That Helps to Accelerate the Project

In order for EMPE to study a custom electric motor request more thoroughly, it is useful to provide all available technical documentation.
For example:
  1. Drawings of the machine or installation.
  2. Shaft or coupling drawing.
  3. Data sheet of the existing motor, if applicable.
  4. Photographs of the mounting arrangement.
  5. Operating conditions.
  6. Problems identified with previous solutions.
  7. Electrical requirements.
  8. Dimensional restrictions.
  9. Required standards or certifications.
  10. Estimated production volume.
It is not always possible to have all the information available from the outset. However, the clearer the starting point, the more precise the technical proposal will be.

What Happens When This Information Is Not Properly Defined

When an enquiry arrives incomplete, the risk is not simply that a piece of data is missing. The risk is designing on the basis of assumptions.
And in industrial electric motors, assumptions are costly.
Poor definition can lead to:
  1. Integration problems.
  2. Additional costs due to subsequent modifications.
  3. Vibrations or misalignment.
  4. Overheating.
  5. Insufficient protection against the environment.
  6. Loss of performance.
  7. Increased maintenance.
  8. Reduced service life.
Manufacturing to order does not mean complicating the project. It means defining it properly from the outset.

A Good Technical Enquiry Improves the Final Result

The manufacture of a custom electric motor begins with a sound technical conversation. It is not simply a matter of requesting a different motor, but of explaining what the application needs and what conditions the equipment must withstand.
When EMPE has clear information on application, environment, shaft, dimensions, duty rating, temperature, efficiency and validation, it can study a solution that is more precise, reliable and coherent with the project.
In short: the better the need is defined, the better the motor is manufactured.
If your company requires an electric motor tailored to a specific application, EMPE can study the technical requirements of the project and help you define a bespoke solution from the very beginning.

Related EMPE Articles for Further Information

  1. Custom industrial electric motor, to explore in depth the parameters that can be tailored according to each application.
  2. Custom shafts: precision and reliability through in-house machining, particularly useful if the project requires a specific shaft geometry.
  3. Energy-efficient electric motors for sustainable industry, recommended if the project objective is linked to efficiency, performance and validation.
  4. Industrial agility in electric motor manufacturing, for further information on customisation, electrical configuration, mechanical design and integration with control systems.

Technical References

  1. IEC 60529, reference standard for IP protection ratings against the ingress of dust and liquids.
  2. IEC 60034-1, international standard for rotating electrical machines, rating and performance.
  3. NEMA, technical documentation on AC motors and insulation class.