Perform Forward and Reverse Biased IGBT/Diode Tests for Frames 8...15

Follow these steps to perform forward and reverse biased IGBT/diode tests on the frames 8…15 power modules.
  1. Review the product advisories in Before You Begin.
  2. Remove power from the system.
  3. Remove the power module from the enclosure.
  4. IMPORTANT: The actual voltage readings can vary depending upon your equipment. If your readings are not near the values that are indicated in these tables, verify that the actual voltage that is measured is consistent for each phase of the power module.
    IMPORTANT: Residual voltage on the DC bus capacitors can affect a ".OL" (open circuit) reading. If the capacitors are discharged (less than 1 volt), the meter initially shows a low voltage. This voltage reading is the residual bus voltage plus the drop through the low side diodes. The meter gradually charges the bus, and the voltage slowly increases, until eventually the meter switches to “.OL”. The voltage increase and eventual display of “.OL” can take several minutes to occur.
  5. On the digital multi-meter, select the “Diode Test” mode and complete the forward-biased diode tests on the power module by using the test points in this table.
  6. Forward-biased Diode Test Points and Meter Readings
    + Meter Lead to Test Point
    – Meter Lead to Test Point
    Nominal Meter Reading
    –DC
    U/T1
    The value typically rises to between 0.20V and 0.75V. If the value is outside this range, contact Technical Support.
    –DC
    V/T2
    The value typically rises to between 0.20V and 0.75V. If the value is outside this range, contact Technical Support.
    –DC
    W/T3
    The value typically rises to between 0.20V and 0.75V. If the value is outside this range, contact Technical Support.
    U/T1
    +DC
    The value typically rises to between 0.20V and 0.75V. If the value is outside this range, contact Technical Support.
    V/T2
    +DC
    The value should gradually rise to between 0.20V and 0.75V. If the value is outside this range, contact Technical Support.
    W/T3
    +DC
    The value typically rises to between 0.20V and 0.75V. If the value is outside this range, contact Technical Support.
  7. On the digital multi-meter, select the “Diode Test” mode and complete the reverse-biased diode tests on the power module by using the test points in this table.
  8. Reverse-biased Diode Test Points and Meter Readings
    + Meter Lead to Test Point
    – Meter Lead to Test Point
    Nominal Meter Reading
    U/T1
    –DC
    ".OL" (open circuit)
    V/T2
    –DC
    ".OL" (open circuit)
    W/T3
    –DC
    ".OL" (open circuit)
    +DC
    U/T1
    ".OL" (open circuit)
    +DC
    V/T2
    ".OL" (open circuit)
    +DC
    W/T2
    ".OL" (open circuit)
    Frames 8...15 Power Module Power Terminal Locations
    A frame 8…15 power module showing the power terminal locations
    Item
    Name
    Item
    Name
    A
    +DC
    D
    S/L2, V/T2
    B
    –DC
    E
    T/L3, W/T3
    C
    R/L1, U/T1
    —
    —
  9. If the product fails the meter readings, replace the power module.
  10. Before you place the drive or bus supply back into service, complete the Start Up After Repairs procedure.
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