DeltaV Series 2 Redundant I/O > Example switchover situations

Excessive withdrawal of current causes hardware error

Providing a constant 24 VDC without current limit protection to the inputs of a redundant AI card for long periods of time during normal operation of the DeltaV system can cause a hardware error on the card. The excessive current damages the card's internal components. To correct this issue:

  1. Replace the card with the blinking red LED as it is probably damaged.
  2. Use a multimeter or other measurement device to determine if any of the channels are drawing 24 VDC without current limit protection and fix this problem.
  3. Reset the cards by removing each card from the carrier and then re-inserting it into its slot.
  4. Open DeltaV Diagnostics (click Start → DeltaV Operator → Diagnostics).
  5. For each card, right-click the card, and then select Clear Saved Fault Information.