How To Judge The 20 Slots Heating Motor Armature

With four aspects

1. Bar to Bar resistance,0.01mΩ~10mΩ (Out of range display OVER)

Four-terminal measurement to ensure accuracy

2. Welding resistance,0.001mΩ-10mΩ (Out of range display OVER)

Six-terminal measurement to ensure accuracy

3. Cross resistance 0.01mΩ-10mΩ

Four-terminal measurement to ensure accuracy

4. Surge 100-1000V (100V/time)

Pulse crest:0.5u sec, Frequency 1~40MHz

Standard waveform is Write, OK waveform is Green, NG waveform is Red

5. Isolation resistance DC 500V

Testing time:1~10s (0.1s/time)

Range:1~500MΩ

Accuracy: ≤±5%

6. Hipot AC 100-1000V

Testing time:1~10s (0.1s/time)

Armature commutator bars ≤ 36 bars

Testing panel cycle time: 8~9s (according to 33 bars)

 

Motor Manufacturer Question and Wind Automation Answer

Motor Manufacturer K from Turkey

During welding resistance measurements on a 20-bar commutator, I generally obtain values between 0.02 mΩ and 0.04 mΩ. However, occasionally, I encounter values around 0.3 mΩ on some commutator bars.

Could you please advise what the maximum acceptable welding resistance should be in such cases? For instance, would setting a maximum limit of 0.1 mΩ be appropriate?

How can we calculate or define a proper threshold for this parameter?