LTi Synchronous Motor LST/LSH Replacement Selection Guide

Check the brake: If the original motor is equipped with a brake, the new motor must also be equipped with a brake, and the release voltage and holding torque must meet the requirements.

Verify DC bus voltage: 320V and 560V cannot be mixed unless the driver supports a wide voltage range and is reset.

Check the mechanical interface: the flange joint, bolt hole spacing, shaft diameter, shaft length, and keyway size must match. If a perfect match is not possible, consider customizing the design (option X).

After replacement, recalibrate the driver parameters, including motor data, encoder data, current loop, speed loop, and position loop. Suggest using LT's DRIVE MANAGER software to load the corresponding motor database.

Test run: Run at low speed first to check the encoder direction, brake release, motor temperature, vibration, and noise. Then gradually increase the speed and load, and observe whether the current and torque are normal.

Common faults and troubleshooting

Motor overheating: Check if the load exceeds the continuous torque, if the cooling conditions are good, and if the ambient temperature is too high. If the surface temperature of the motor exceeds the allowable value, the load should be reduced or ventilation should be improved. Check if the motor PTC or KTY is correctly connected to the driver and if the temperature protection parameters are set correctly.

Encoder alarm: Check if the encoder cable is securely connected, if the shielding layer is grounded, and if the cable is damaged. If using a Parser, check if the rotation signal is normal; If using an absolute value encoder, check the battery voltage (multiple cycles) and protocol configuration. When the encoder direction is incorrect, A and B can be exchanged or the driver parameters can be adjusted.

Brake not released: Check if the 24V power supply is normal and if the release current has reached the rated value. Check if the rectifier is working and if the DC side switch is functioning properly. If there is noise from the brake, it may be due to worn friction plates or improper air clearance.

Motor vibration or noise: Check the alignment of the coupling, whether the bearings are damaged, and whether the encoder is loose. Check if the current loop parameters of the driver are appropriate and if the carrier frequency is too high.

Excessive axial force causing bearing damage: Check the installation form and whether the axial force exceeds the allowable value when installed vertically. If using pulleys or gears, ensure that the radial force application point does not exceed the allowable value.