Placement angle mistake in ST Manual

[SRedd.5]

I am referring to the above diagram and the placement angle delay is mentioned as 270. How is it? According to me it shall be 90Degrees. 

[Gael A]

Hello SRedd.5,

It depends on the reference used to calculate the delay. Here, we are taking Phase A (where the BemfA is at maximum value) as reference. The diagram shows H1 is 90° behind Phase A, which would be an angle of -90°. However, H1 is also 270° before Phase A, and as we prefer positive value, we will set +270° instead of -90°.

If our reference was H1, we would indeed have a delay of +90°.

Hope this will help,
Gaël A.

[SRedd.5]

I really need help on the below issue, i have captured the 3 hall signals and the Bemf and the Hall 1 signals as shown. I have run the motor in clockwise direction, as per the waveform the i could identify the H1, H2, H3 waveforms. I took the A+, B- BEMF waveform and the hall H1 waveform and the phase difference is -90. Since i took line voltage Bemf and is leading the phase voltage i calculated the delay as -60. When i give -60 the motor does not run, but only if i give 60Degrees it runs but with noise seem to be unstable. Please help to resolve the issue.