NEUTRAL GROUNDING RESISTOR(NGR)

NEUTRAL GROUNDING RESISTOR

A neutral grounding resistor is a component used in electrical power systems to limit the fault current that can flow through the neutral point of a three-phase power transformer. It is a resistor that is connected between the neutral point and ground in a power system, with the purpose of limiting the current that flows in the event of a fault.

The neutral grounding resistor is designed to limit the current to a safe level that will not cause damage to equipment or harm to people. In addition, it helps to reduce the risk of electrical fires that can occur due to the flow of excessive fault currents.

Overall, neutral grounding resistors are an important safety feature in electrical power systems that help to protect people and equipment from the harmful effects of fault currents.

How neutral grounding resistor limit fault current??
A neutral grounding resistor limits fault current by increasing the impedance between the neutral point of a three-phase power system and ground. This impedance restricts the amount of current that can flow in the event of a fault, reducing the magnitude of the fault current to a safe level.

When a fault occurs in a power system, such as a short circuit between a phase conductor and ground, a high current will flow through the fault. In a solidly grounded system (where there is no neutral grounding resistor), this fault current will be limited only by the impedance of the power system, which can be very low. This can result in a high magnitude of fault current, which can cause equipment damage or pose a safety hazard to people.

By using a neutral grounding resistor, the fault current is limited because the resistor introduces additional impedance into the power system. This increased impedance reduces the magnitude of the fault current, limiting its potential to cause damage or harm.

NGR Calculation