What are the faults that are likely to occur in a power transformer?

The principle faults which occurs inside a power transformer are categorized as,

• Insulation breakdown between winding and earth.
• Insulation breakdown in between different phases.
• Insulation breakdown in between adjacent turns i.e. inter – turn fault.
• Transformer core fault.

What are the types of fault in transformer?

Transformer fault conditions

• Earth faults.
• Core faults.
• Interturn faults.
• Phase-to-phase faults.
• Tank faults.
• External factors.

What is transformer fault current?

Short circuit fault current I(fault) in kilo amps is equal to 100 times of transformer’s rating S(kVA) in kVA divided by the multiplication of root 3, transformer’s secondary voltage V(V) in Volts and percentage impedance in percentage. I(fault) = S(kVA) x 100 / (1.732 x V(V) x \%Z). The \%Z will lie between 4 to 10\%.

What are the different types of faults in electrical power systems?

There are mainly three types namely line to ground (L-G), line to line (L-L) and double line to ground (LL-G) faults. Line to ground fault (L-G) is most common fault and 65-70 percent of faults are of this type. It causes the conductor to make contact with earth or ground.

What is the function of a current transformer when used on three phase services?

The principal function of a current transformer is to produce a manageable level of voltage and current, proportional to the current flowing through its primary winding, for the operation of measuring or protective devices.

What do you understand by transformer testing?

The transformer testing can be done to determine the specifications, and performance of an electrical transformer. To meet the specific design and specifications, transformer testing should be done during the manufacturing process.

What are faults types?

Different types of faults include: normal (extensional) faults; reverse or thrust (compressional) faults; and strike-slip (shearing) faults.