What is a servo press?

A servo press uses servo motors for precise force and position control during forming operations.

How do I calculate servo press tonnage?

Use our free tonnage calculator at servopress.club/tonnage-calculator.html

Servo Motor Overheating: Diagnosis and Solutions

admin

Servo motor overheating is one of the most common causes of unplanned downtime. Here's how to diagnose and fix it.

## Temperature Limits

Most servo motors are rated for continuous operation at 40°C ambient with winding temperature rise of 80°C (Class B) or 105°C (Class F). Sustained operation above rated temperature **reduces insulation life by 50% for every 10°C excess**.

## Common Causes

**1. Duty Cycle Exceeds Rating**
Calculate actual duty cycle: (on-time / cycle-time) × 100%. Compare to motor's rated duty cycle.

**2. Cooling Fan Failure**
Check fan rotation direction — reverse rotation gives only ~30% of rated airflow. Clean fan blades regularly.

**3. Ambient Temperature Too High**
Derate motor by 3% per °C above 40°C. Consider adding forced air cooling for hot environments.

**4. Servo Gain Tuning Issues**
Poorly tuned gains cause the motor to hunt (oscillate), generating heat without useful work. Check for oscillation with a servo analyzer.

**5. Mechanical Binding**
Increased mechanical resistance forces the motor to work harder. A 10% increase in mechanical load can cause 20% increase in motor heating.

## Solutions

- Install motor temperature monitoring with alarm at 100°C and shutdown at 120°C
- Add thermal imaging to monthly maintenance routine
- Consider motor with higher thermal class (Class H) for demanding applications
- Optimize speed profile to reduce RMS current — slower approach, faster return

anna_controls

Temperature monitoring is key but most shops only look at the drive's estimated temperature, not actual. I always recommend adding a PT100 RTD directly on the motor winding if the motor doesn't have one built in. The drive's thermal model can be off by 15-20?C, especially on intermittent duty cycles.

raj_maintenance

We had chronic overheating on a 200T press that turned out to be a partially blocked cooling fan filter. Motor was hitting 140?C every afternoon when the shop got hot. Cleaned the filter, problem gone. Now it's on our daily checklist. Sometimes the fix is embarrassingly simple.