Application guide
Balancing electric motor rotors
A motor shakes for two quite different reasons, electromagnetic or mechanical. You can tell them apart before any balancing: cut the power and watch how the vibration disappears.
Specifications checked: September 2026
Direct answer
Is the vibration electrical or imbalance?
Cut the power: if vibration disappears instantly, the cause is electromagnetic; if it decays gradually with speed, imbalance is likely. Rigid motor rotors are then balanced in two planes in their own bearings or on a stand.
Before the first run
Mechanical checks come first
- Separate electrical and mechanical causes: cut the power and watch whether vibration disappears instantly or decays with speed.
- Check bearings, soft foot, coupling alignment and the condition of the rotor cooling fan.
- Confirm a stable speed and a dominant 1× component before adding any mass.
Order of work
A controlled balancing sequence
- 01
Balance the rotor in its own bearings at operating speed, or on a stand after removal.
- 02
Attach sensors to both end shields close to the bearings and aim the tachometer at the shaft mark.
- 03
Use the cooling fan, key area or dedicated grooves as accessible correction planes.
- 04
Measure Run 0, then the trial runs, and install the calculated correction in one or two planes.
- 05
Verify with a trim run and, when possible, a run-down check: imbalance falls with speed squared.
Selection support
Not sure which system fits your machine?
Just write what machine you have — a fan, a crusher, a pump, anything that rotates. Our engineers will take it from there and confirm the right setup before you order.