Neutral Grounding Resistors

Short circuit between phase and ground can result in irreversible damage to networks and equipment; it is therefore of the utmost importance to be able to control and reduce their effects: Grounding resistors limit the fault current that arises due to phase neutral short circuit. Grounding through resistor offers several advantages with respect to alternative methods (such as insulated grounding, direct grounding or grounding through a reactance). The main advantages are: easier detection of fault location, limitation of fault current, no transient overvoltage.

Relevant parameters in the design of a Neutral Grounding Resistor may vary greatly: MINGRUI has developed a line of standard products (for the most common requirements) along with tailored products, each developed and customized according to the required project characteristics.

The essential parameters needed to design a Grounding resistor are:

Nominal voltage

Fault current

Fault duration (10s is customary)

Other relevant parameters are:

Protection degree of enclosure: from IP00-i.e. no enclosure to IP55, standard solution IP23

Enclosure finish: our standard is mild galvanized, but different stainless steel grades are available; Painting in the desired RAL color is also an option

Continuous current rating: it may affect significantly the performance of the resistor, especially when high IP degrees are required.

Environment and elevation: we design resistors for the harshest industrial or natural settings

Auxiliary components: during our many years of operation we have selected a number of trusted suppliers for a wide choice of components, such as Current Transformers, Switches, Disconnectors, etc.