Skip to main content
blog | Motor Derating Due To High Ambient Temperatures |
|
2 minute read

Question:

How do I calculate a motor’s continuous torque when it is operating in an environment above its rated temperature? Our selected motor’s continuous torque (Tc) is rated in a 40°C ambient, how can I estimate the motor’s continuous torque during my worst-case ambient temperature of 55°C?

Answer:

Motor Specification SheetFirst you will need to know the maximum winding temperature of the motor based on the published ratings data (e.g. 40°C ambient).

If not directly given within the motor’s catalog data, it can be determined by adding the 40°C to the published delta (Δ) Temperature of the winding (assuming it is given; if not, you will need to contact the motor’s manufacturer. Assuming it is given to be 100°C, the maximum winding temperature = 140°C).

Temperature derating equation

where ΔTemp Rated = Temp(maximum winding) – Temp(rated ambient)

 

So the new continuous torque Tc(new) would be:
Example Equation for Temperature Derating

Performance CurveTorque required, Tr(new) at a specific RPM, can also be estimated by graphically finding the maximum continuous capability with the specified ambient temperature at the desired RPM, from the motor’s performance curve (PC), if not available from the motor’s data sheet.

This is most often done by graphically determining Tr(40°C) at the desired RPM from the motor’s PC and using it in place of Tc(40°C), in the above formula.

Consult an Expert

AKMA Servo Motors

The lightweight AKMA servo motor is designed for harsh environments like food and beverage processing, and delivers performance and reliability.
Learn More

Engineer the Exceptional

Learn how to engineer exceptional machines, robots and vehicles with the highest-performing, most reliable motors, drives, automation solutions and more.

Learn More

Related Resources

Accelerating the Development of Next-Generation Prostheses and Exoskeletons >

Learn how Kollmorgen servo technology is helping OEMs accelerate the design of next-generation prostheses and exoskeletons.

Stop, hold and go safely: Motion tuning for vertical loads >

When designing motion for applications such as vertical gantries and hoists, you need to take special care to ensure operator safety and operational efficiency. Let’s discuss best practices for meeting the particular challenges involved.

What are the Five Major Components of a Brushless Servo Motor >

Servo motors are used in numerous markets to power machines, instruments, robots, and other factory automation applications. This blog addresses five major elements of a conventional brushless DC servo motor: the rotor, stator, bearings, feedback and…
What is considered a low voltage motor?

What is Considered a Low Voltage Motor? >

The Low Voltage Directive defines low voltage from 50 – 1000 Vac, or 120 – 1500 Vdc, which is based on the mains voltage used to power the electrical system and ties in with specific IEC regulations on safety and risk of shock and arcing. When low…

Why Does My Stepper Motor Get Hot? >

All electric motors heat up during operation, which is simply a product of passing current through a coil of wire. Electric motors use copper wire to form coils that are part of the electromagnetic circuit required to produce rotation. While copper…
Servo Motor Design Considerations for Hazardous Environments

Servo Motor Design Considerations for Hazardous Environments >

While servo motors and drives are prevalent in a wide variety of industrial applications, what should be considered when they operate in extreme or hazardous environments? In many cases, the motor itself operates in the extreme environment, while the…

What are the basic elements of a servo system? >

Working with motion control experts like Kollmorgen makes selecting a servo system easier and faster, resulting in an optimal system for the application.

How to Customize a Servo Motor - Standard vs Custom >

When and how to customize a standard servo motor depends on the predicted benefits derived from the customization that should include a solution tied to form, fit, and function. Learn more.

The Big Debate – Stepper vs Servo >

What is the best motor technology to use in a motion control application? There are numerous technologies to create motion, from hydraulic to pneumatic or electromechanical. In the world of precision motion control, many machine designers face a…