Common Causes for Stepper Motor Failure

Problem: Stepper motor wires were disconnected while the driver was powered up.

 Solution: Avoid performing any service to the stepper motor, driver or controller while the power is on, especially in regard to the motor connections. This precaution is imperative for both the driver and the technician/installer.

Problem:The stepper motor has a shorted winding or a short to the motor case.

Solution: It is likely you have a defective stepper motor. Do not attempt to repair motors. Opening the stepper motor may cause the motor to lose its magnetism, causing poor performance. Opening of the stepper motor case will also void your warranty. The motor windings can be tested with an ohmmeter. As a rule of thumb, if the stepper motor is a frame size of NEMA 08, 11, 14, 15, 17, 23, or 34 and the warranty period has expired, it is not cost-effective to return these stepper motors for repair. Contact the factory if you suspect a defective stepper motor that is still under warranty, or if the stepper motor is a NEMA frame size 42 .

Problem: Environmental factors are less than ideal.

Solution: Environmental factors such as welding, chemical vapors, moisture, humidity, dust, metal debris, etc., can damage the electronic components and the stepper motor. Protect drivers, controllers and stepper motors from environments that are corrosive, contain voltage spikes, or prevent good ventilation. Anaheim Automation offers products in several line voltage ranges, as well as splash-proof, IP65 rated stepper motors. For wash-down or explosion-proof motors, contact the factory directly. For AC lines containing voltage spikes, a line regulator (filter) will likely be required.

 NOTE:If your application requires welding, or if welding is done in the same work environment, contact the factory for advice on how to protect the stepper motor driver and controller.

Problem:The stepper motor is back-driving the stepper driver.

Solution: A stepper motor being turned by a load creates a back EMF voltage on the driver. Higher speeds will produce higher voltage levels. If the rotational speed gets excessively high, this voltage may cause damage to the driver. This is especially dangerous when the motor is back-driven while the driver is still on. Place a mechanical stop or brake in applications which may be subject to these phenomena.

PLEASE NOTE:Technical assistance regarding its Stepper Motor product line, as well as all the products manufactured or distributed by Anaheim Automation, is available at no charge. This assistance is offered to help the customer in choosing Anaheim Automation products for a specific application. However, any selection, quotation, or application suggestion for a Stepper Motor, or any other product, offered from Anaheim Automation’s staff, its' representatives or distributors, are only to assist the customer. In all cases, determination of fitness of the custom Stepper Motor in a specific system design is solely the customers' responsibility. While every effort is made to offer solid advice regarding the Stepper Motor product line, as well as other motion control products, and to produce technical data and illustrations accurately, such advice and documents are for reference only, and subject to change without notice.