Inter-Turn-vs-Inter-Coil-Fault
Inter-turn Fault Inter-coil Fault, Inter-phase Fault
- Inter-turn faults occur within a single coil, inter-coil faults occur between coils of the same phase, and inter-phase faults occur between coils of different phases.
- Inter-turn faults tend to have less impact on motor performance compared to inter-coil or inter-phase faults.
- Inter-coil faults cause circulating currents between coils in the same phase. Inter-phase faults cause circulating currents between phases, resulting in more damage.
- Inter-turn and inter-coil faults may be harder to detect than inter-phase faults which significantly unbalance the motor phases.
An inter-coil fault is not simply an extreme version of an inter-turn fault. While they are related, they are distinct types of faults:
- Inter-turn fault - Occurs within a single coil, involving turns of the same winding shorting to each other.
- Inter-coil fault - Occurs between two separate coils or windings, shorting between those coils.
An inter-turn fault is confined to one coil and essentially shorted turns within that one coil. It may involve a small number of turns or many turns shorted, but the fault stays within that coil.
An inter-coil fault jumps from one coil to another, resulting in circulating currents between two coils or windings. It is not just an extension of the inter-turn fault to additional turns, but a fault bridging two physically separate coils.
So while inter-turn faults can vary in severity based on the number of shorted turns, the inter-coil fault is a distinctly different phenomenon involving a short bridging across two coils. The inter-coil fault can be thought of as more severe in that it bridges distinct windings rather than occurring within a single winding. But it is not simply an escalated inter-turn fault, but rather a separate type of fault altogether.
The distinctions lie in the physics of what is shorting to what - shorted turns within a coil vs. a short bridging across coils. This results in differing failure modes and effects on motor performance. So in summary, an inter-coil fault may be more damaging, but is not just an extreme version of an inter-turn fault.