Connecting the neutral point of a transformer to the earth (grounding) is done for numerous fundamental reasons:
1). Safety
2). Voltage Stabilization
3). Lightning Protection
4). Noise Reduction
5). Fault identification
6). Reference Point
1). Safety
Grounding helps to keep the voltage in the system at a safe level & provides a conduit that fault currents to securely dissipate into the ground. Grounding helps prevent harmful voltage levels from accumulating on exposed metal portions of equipment and structures in the case of a fault, such as a short circuit.
2). Voltage Stabilization
Grounding contributes in the voltage stability of the system. The voltage at the neutral point frequently remains close to 0 volts by connecting it to the earth. This helps to keep the entire electrical system on track and eliminates excessive voltage imbalances.
3). Lightning Protection
Grounding allows lightning strikes to effectively dissipate into the ground, lowering the chance of damage to transformer & other electrical components.
4). Noise Reduction
Grounding can aid in the reduction of electromagnetic interference (EMI) & radio-frequency interference (RFI) in electrical system. Unwanted electrical noise can be diverted to the ground through connecting the neutral to the earth.
5). Fault identification
Grounding enables the identification of system defects. As a fault occurs, it can generate a ground fault current, which protective relays can detect and use to initiate preventive measures that include circuit breaker tripping.
6). Reference Point
The earth connection serves as a steady reference point for electrical system, that is necessary for correct voltage and current measurements as well as the proper operation of protection devices.
In general, grounding the neutral terminal in a transformer is an important safety and operational step that contributes to the safe and dependable operation of the electrical systems. It facilitates in the prevention of electrical defects, the stabilization of voltages, and the reduction of the risk of the electrical hazards.