Why Capacitor Bank should be left Ungrounded?

Capacitor banks play an important role in electrical systems, regulating voltage and power factor.

However, leaving these capacitor banks ungrounded is a typical industrial practice.

Here are the main reasons why this technique is used:

  • Prevent Fault Propagation
  • Minimize Ground Fault Currents
  • Improved Detection of Ground Faults
  • Avoid Resonance Issues
  • Conformity to Standards and Practices
  • Improved System Reliability

Prevent Fault Propagation

Leaving capacitor banks ungrounded assists to prevent fault propagation. In the case of a ground fault, an ungrounded capacitor bank isolates the problem and prevents it from spreading to other areas of the electrical system. This confinement lowers the potential of extensive electrical damage while improving overall system stability.

Minimize Ground Fault Currents

Ungrounded capacitor banks reduce the magnitude of ground fault currents. If a capacitor bank is grounded, a defect might cause a direct path to the ground, resulting in large fault currents.

These large currents can cause significant damage to equipment and pose a safety risk. An ungrounded configuration restricts these currents, safeguarding both the equipment & the personnel.

Improved Detection of Ground Faults

An ungrounded capacitor bank enables it easier to identify ground issues. Ground faults in a grounded system can sometimes go undetected or are difficult to find. With an ungrounded system, monitoring equipment can detect the presence of a fault more easily, allowing for faster reaction and repairs.

Avoid Resonance Issues

Grounded capacitor banks can cause resonance circumstances with the power system’s inductance. This resonance can increase specific harmonic frequencies, potentially causing overvoltage and damage to other components. By leaving capacitor banks ungrounded, the likelihood of resonance and its negative consequences is reduced.

Conformity to Standards and Practices

Many industrial standards and electrical codes suggest or require that capacitor banks be kept ungrounded. Adhering to these standards assures compliance while also promoting best practices in the electrical system design & safety.

Improved System Reliability

Leaving capacitor banks ungrounded improves overall system reliability. By minimizing the hassles and risks connected with grounding, the electrical system runs more smoothly, with fewer disruptions and maintenance problems.