What information must motor controllers be marked with?

Motor controllers must be marked with both the maximum rated voltage and the maximum horsepower or current rating for several important reasons.

Firstly, the maximum rated voltage is crucial for ensuring that the motor controller operates safely within its designed electrical limits. Exceeding this voltage can lead to equipment failure, insulation breakdown, or even hazardous conditions. Proper marking helps users to quickly identify the appropriate voltage level needed for safe operation.

Secondly, the maximum horsepower and current rating is essential for understanding the load that the controller can handle. This rating indicates the maximum power output the controller is designed to manage without overheating or failing. If a motor exceeding this rating were connected, it could result in damage to the motor controller or the connected motor, posing both a safety risk and potential disruption to operations.

By providing both of these specifications on the labeling, users can ensure that they select the appropriate controller for their application, preventing incorrect installations that could compromise safety and equipment integrity. This dual designation is a requirement upheld by electrical codes and standards to support both safety and performance in electrical installations.