Troubleshooting A Servo Motor Problem02/25/2021Troubleshooting a servo motor problem can be a formidable task, especially due to it being part of a closed loop system with the servo controller. Servo motor problems can occasionally be diagnosed with a simple visual inspection of the servo motor installation and its cabling, but when it’s not so obvious, isolating the issue between the motor and the servo controller can be more problematic. Some common servo motor problems are listed below, along with possible causes and solutions. *Many servo motor problems cause the servo motor controller to give a fault code, which is shown on its display or LED indicators. Check for this first before proceeding with the troubleshooting list below. Refer to the servo controller’s manual for a description of the fault code or indicators for possible solutions. *CAUTION – HIGH VOLTAGE* High voltage can be present when the servo system in powered up – only experienced technicians should attempt to troubleshoot these systems with the power on. It is recommended power be removed before troubleshooting. Common Servo Motor Problems & Possible Solutions: Overheating Overloaded Reduce load or peak loads Reduce number of load starts / cycles Motor undersized – increase motor size Blocked ventilation Blow out internal ventilation passages If fan cooled, clean ventilation system & check cooling fan(s) Wiring or tuning problem Check that connectors / connections are tight and no frayed wiring Autotune motor with controller Bearings worn or possibly replaced with incorrect type Have motor serviced High ambient temperature Reduce ambient temperature around motor Motor will not turn Controller not receiving run or speed command signal Check controller signals Loose motor coupling Check all couplings Bad connection Check all motor connectors, connections, and cables Motor has overheated (motor thermal) Check motor thermals Check controller for any faults related to motor Will not come up to speed or shuts off Motor may be overloaded Check load – reduce if possible Check for correct settings on servo controller Possible tuning issue with controller Autotune motor with servo controller Motor overheating *See Overheating (above) Voltage drop due to bad connection or wiring Inspect all wiring and connections Motor runs away Possible loss of feedback Check feedback device and connections Incorrect setup with servo controller Check controller setup/settings Controller or motor wiring issue Check controller and motor wiring Unusual noise coming from motor Worn bearings Have motor serviced Bad or loose coupling to motor Check motor coupling Noise on feedback or controller speed reference signals Check for proper grounding and inspect all cables / connections Excessive vibration Misalignment of motor with driven load Check alignment, couplings, and for possible shim movement Unbalanced motor or load Check both for balance issues *If belt coupled, remove belt, and see if motor still out of balance Motor mounting Inspect for loose or worn mounts Worn motor bearings Have motor serviced Smoking or bad odor Motor overheating *See Overheating (above) Bad motor wiring or connection Check all motor wiring, connectors, and connections Bad motor winding Have motor serviced If while troubleshooting a servo motor problem you determine your servo motor is defective, or are just not sure, give us a call at 800-732-4695. Our servo motor repair service is a great cost-saving alternative to purchasing a new, expensive replacement servo motor. PES also offers repair solutions for servo controllers. Back To Blog
Troubleshooting A Servo Motor Problem02/25/2021Troubleshooting a servo motor problem can be a formidable task, especially due to it being part of a closed loop system with the servo controller. Servo motor problems can occasionally be diagnosed with a simple visual inspection of the servo motor installation and its cabling, but when it’s not so obvious, isolating the issue between the motor and the servo controller can be more problematic. Some common servo motor problems are listed below, along with possible causes and solutions. *Many servo motor problems cause the servo motor controller to give a fault code, which is shown on its display or LED indicators. Check for this first before proceeding with the troubleshooting list below. Refer to the servo controller’s manual for a description of the fault code or indicators for possible solutions. *CAUTION – HIGH VOLTAGE* High voltage can be present when the servo system in powered up – only experienced technicians should attempt to troubleshoot these systems with the power on. It is recommended power be removed before troubleshooting. Common Servo Motor Problems & Possible Solutions: Overheating Overloaded Reduce load or peak loads Reduce number of load starts / cycles Motor undersized – increase motor size Blocked ventilation Blow out internal ventilation passages If fan cooled, clean ventilation system & check cooling fan(s) Wiring or tuning problem Check that connectors / connections are tight and no frayed wiring Autotune motor with controller Bearings worn or possibly replaced with incorrect type Have motor serviced High ambient temperature Reduce ambient temperature around motor Motor will not turn Controller not receiving run or speed command signal Check controller signals Loose motor coupling Check all couplings Bad connection Check all motor connectors, connections, and cables Motor has overheated (motor thermal) Check motor thermals Check controller for any faults related to motor Will not come up to speed or shuts off Motor may be overloaded Check load – reduce if possible Check for correct settings on servo controller Possible tuning issue with controller Autotune motor with servo controller Motor overheating *See Overheating (above) Voltage drop due to bad connection or wiring Inspect all wiring and connections Motor runs away Possible loss of feedback Check feedback device and connections Incorrect setup with servo controller Check controller setup/settings Controller or motor wiring issue Check controller and motor wiring Unusual noise coming from motor Worn bearings Have motor serviced Bad or loose coupling to motor Check motor coupling Noise on feedback or controller speed reference signals Check for proper grounding and inspect all cables / connections Excessive vibration Misalignment of motor with driven load Check alignment, couplings, and for possible shim movement Unbalanced motor or load Check both for balance issues *If belt coupled, remove belt, and see if motor still out of balance Motor mounting Inspect for loose or worn mounts Worn motor bearings Have motor serviced Smoking or bad odor Motor overheating *See Overheating (above) Bad motor wiring or connection Check all motor wiring, connectors, and connections Bad motor winding Have motor serviced If while troubleshooting a servo motor problem you determine your servo motor is defective, or are just not sure, give us a call at 800-732-4695. Our servo motor repair service is a great cost-saving alternative to purchasing a new, expensive replacement servo motor. PES also offers repair solutions for servo controllers.