How to check the input and output of 900 series VFD by multimeter
Rectifier check (R, S & T)
Using a multimeter set to read diode
complete the following tests:
1) Black lead on the - DC Bus and measure with the red lead on R, S and T input phases, value should read open circuit.
2) Black lead to +DC point and measure to R, S and T. Values= 0.523V +/-10%
3) Red lead on DC and measure with the black lead to R, S and T. Values = 0.623V +/ 10%
4) Red lead on +DC and measure with the black lead to R, S and T. values = open circuit.
Output check (U, V & W)
Using a multimeter set to read diode,
complete the following tests:
1) Black lead on the - DC Bus and measure with the red lead on U, V & W input phases, value should read open circuit.
2) Black lead on the +DC point and measure to U, V & W, values = 0.462V +/-10%
3) Red lead on -DC and measure with the black lead to U, V & W values= 0.461V +/-10%
4) Red lead on +DC and measure with the black lead to U, V & W value should read open circuit.