What is the purpose of a neutral grounding resistor (NGR) in distribution networks?

[Manon_Chaboud]

A Neutral Grounding Resistor (NGR) is used in electrical distribution networks to enhance safety and stability. It limits the current that flows through the neutral line during a ground fault, preventing excessive fault currents that could damage equipment and pose safety risks.

By controlling the fault current, the NGR helps maintain system voltage stability during ground faults, preventing voltage sags and other voltage-related issues.

This also reduces the risk of electrical shocks and minimizes potential damage to electrical equipment, ensuring a safer working environment.

Additionally, the controlled fault current allows protective relay systems to detect and isolate the faulty section of the system more effectively, aiding in quicker fault localization and system restoration.

Ground-Fault Protection (G or ANSI 50N-TD/51N)

[RHH]

This is perhaps an usefull links for Ground-fault protection on MTZ circuit breakers, officially from Schneider Electric; Ground-Fault Protection MTZ's 

Thanks for the explanation about the neutral grounding resistor as well!