Why Do Hall Sensors in Brushless Motors Have 60-Degree and 120-Degree Angles? Will the Motor Run If They Are Installed Incorrectly?

Have you ever encountered this frustrating situation during equipment maintenance or upgrades: after a brushless motor fails and is replaced with a new one that appears identical in model, size, voltage, and power rating, the equipment still fails to operate correctly? The new motor might exhibit severe jerking during startup, weak rotation, abnormal noise, or simply refuse to move at all.

After ruling out common issues like wiring errors or drive parameter mismatches, a frequently overlooked "hidden culprit" is the Hall sensor phase angle – which could be either 60 degrees or 120 degrees. This subtle angular difference is enough to throw the entire drive system into disarray.

The difference between "60-degree" and "120-degree" essentially refers to the angular difference between the rising edges of the output signals from any two of the three Hall sensors.

When you receive a new brushless motor, you can determine whether the Hall angle is 60 or 120 electrical degrees by measuring the three Hall signals and analyzing their phase relationships.

• In a 60-degree configuration: The waveform of the three Hall sensor outputs shows a 60-degree difference between the rising edges of any two signals.
• In a 120-degree configuration: The waveform of the three Hall sensor (H1, H2, H3) outputs shows a 120-degree difference between the rising edges of any two signals. This is the most common and mainstream configuration.

The diagram below provides a simplified reference waveform.

As shown in the left waveform, the rising edge of H1 lags that of H2 by 120 electrical degrees, H2 lags H3 by 120 degrees, and H3 lags H1 by 120 degrees. Therefore, based on the left waveform, it can be deduced that the three Hall sensors are installed at 120-degree intervals.

As shown in the right waveform, the rising edge of H3 lags that of H1 by 60 electrical degrees, and H1 lags H2 by 60 degrees. Therefore, based on the right waveform, it can be deduced that the three Hall sensors are installed at 60-degree intervals.

Solution:

Our commercially available brushless drives only support 120-degree Hall sensors. If you require a drive compatible with 60-degree sensors, please contact our technical support team to assess whether a custom solution is possible.

Technical Warning:

While there are online methods suggesting physical repositioning of Hall sensors or using jumper wires to "convert" the angle, these require extremely high precision and professional equipment. For the vast majority of industrial applications, it is strongly advised against attempting such modifications yourself, as they are highly prone to failure and can introduce unreliable factors.

Updated on: 29/12/2025