Some important things to consider when a motor is operating in environments with higher-than-normal temperatures (>40 degrees C) such as kilns or ovens:
- Use high temperature grease (many synthetic greases have 30 degrees C higher rating than mineral greases);
- Use C4 bearings (greater internal clearance than the usual C3 bearings);
- Use only open bearings (no shield or seal);
- Be sure to specify “heat stabilized bearings” — different bearing manufacturers have their own unique designation. There are bearings capable of operating at considerably higher temperatures than normal;
- Consider running an air line from a compressor to “pipe in” dry compressed air to cool the motor. In kiln applications, it is effective to run a ¼” copper line through a solenoid and tap the end bracket to inject cool air into the motor enclosure when it is running. If practical, insulate the air line to provide the coolest air possible.