Technical Specifications

FAQ

1. What is the main function of the ABB NINT-68C?
The NINT-68C is a main circuit interface board used in applicable ABB drive and inverter systems. It provides an interface between the drive control electronics and the inverter power section, allowing control signals to be transferred toward the power modules while measurement and operating-status information is returned to the control system. This interface is important for coordinating inverter operation and monitoring the condition of the power section.

2. What type of communication is used by the NINT-68C?
The NINT-68C is associated with fiber-optic communication within ABB inverter architectures. Fiber-optic communication provides electrical isolation between the control electronics and power section and helps reduce the influence of electromagnetic interference generated by high-power switching. This makes it suitable for industrial variable-frequency drive environments where reliable signal transmission is required.

3. What signals does the NINT-68C handle?
The NINT-68C handles control, feedback and power-stage status signals. Depending on the specific drive configuration, these signals can include inverter control commands, measurement feedback and diagnostic information from the power section. Exact signal assignments depend on the associated ABB drive hardware, so the applicable electrical drawings and connection information should be used when troubleshooting individual signal paths.

4. Which ABB drive systems can use the NINT-68C?
The NINT-68C is used in applicable ABB industrial drive and frequency-converter systems, including certain ACS600 and ACS800 configurations. Compatibility should be verified against the complete drive configuration, hardware revision and replacement-part information. The model number and order number should be checked before installation to avoid using a board with an incompatible hardware configuration.

5. What symptoms may indicate a faulty NINT-68C?
A faulty NINT-68C or an associated connection problem may cause communication errors between the control electronics and power section, abnormal feedback signals, unexpected inverter alarms or failure of the drive to operate correctly. Intermittent faults can also occur when connectors or fiber-optic connections are contaminated, loose or damaged. These symptoms do not prove that the NINT-68C itself has failed, since control boards, power modules, optical connections and related circuitry can produce similar behavior.

6. How should an NINT-68C fault be diagnosed?
Begin by recording the active fault code and reviewing the drive fault history. Inspect the NINT-68C connectors and associated fiber-optic connections for contamination, damage, poor seating or mechanical stress. Check whether the control system is receiving valid feedback from the inverter power section. If communication-related faults remain, inspect the associated control electronics, optical links and power modules. The NINT-68C should normally be replaced only after the surrounding connections and related components have been checked.

7. What precautions are required when replacing the NINT-68C?
The drive must be completely isolated from its power supply before the board is removed. Appropriate shutdown, discharge and electrical safety procedures must be completed before accessing the internal electronics. All electrical and optical connections should be identified before removal so that they can be restored correctly. ESD protection should be used when handling the PCB. Fiber-optic connectors should be kept clean and protected from scratches, contamination and excessive bending. The replacement board should also be verified against the required model and order number.

8. What should be checked after installing a replacement NINT-68C?
After installation, verify that the board is correctly secured and that all electrical and fiber-optic connections are properly seated. Restore power according to the approved commissioning procedure and check the drive diagnostic system for communication or power-stage faults. Confirm that control commands and feedback signals are exchanged correctly between the control electronics and inverter section. A controlled functional test can then be performed where permitted by the equipment commissioning procedure. If the original fault remains, the control board, fiber-optic links, power modules and associated wiring should be investigated instead of immediately assuming that the replacement NINT-68C is defective.