Description

stainless steel  resistor in door neutral  earthing Resistor (NER)

Application:



      Neutral Grounding Resistor iscurrent limiting electrical equipment which connects between neutral point of the generator, transformer and the earth. When the grid line fails, the voltage of power supply neutral point will be shifted, especially in the cable power grid system, capacitive current to ground is relatively large. When the current is greater than the regulated value, it will produce arc grounding overvoltage, so that the non-fault phase-to-ground voltage increase dramatically, which damage the insulation of the equipment, form a two-point or multi-point ground short circuit and cause blackouts accident.

The purpose of using neutral grounding resistor is to inject the resistive current into the point of failure, which will make the grounding fault current become the nature of resistance-capacitance, and decrease the phase difference with the voltage. Over-voltage is limited at certain level in order to improve the sensitivity of relay protection equipment and to achieve the trip, quickly find fault line and standby switch, so that it can effectively protect the normal operation of the system.



Neutral grounding device is applied to the neutral grounding system of voltage level from 0.4kV to **0kV distribution network. It has been widely used in the substation or power plant in the electricity system. The application in enterprise power system such as mining, petrochemical and others have become increasing widespread. It has significantly improved system reliability and safe operation.



Characteristics:



•  Big power, highcurrent withstanding: 1~***0A



•  Wide range for voltage: 0.*8kV~**0Kv



•  Allowable rated time: 5S,*0S,*0S,*0S,*0MIN,continuously



•  Wide range for resistance value: 0.*1~***0Ω



•  Little maintenance, ease of dismantlement and replacement



•  Compact framework, ease of installation



•  Protection degree for enclosure: IP*0~IP*5,Available for indoor and outdoor



• Switches, breakers, CT, PT and etc can be subsidiarily installed



 



Optional Accessories



•  Intelligent monitoring device: monitor current, temperature and number of failures



•  Isolated switch



•  Current transformer, voltage transformer



•  Temperature and humidity controller and heater



•  Lighting in the cabinet

ApplicableStandards

The design of the product complies with the flowing standards:

 DL/*******1                   Neutral Grounding Resistor in Power Distribution

 IEC**6                             Dry-Type Power Transformer

 DL/T*******7                 Overvoltage Protection and Insulation Co-ordination of AC

                                            Electrical Equipments

IEC***1                             Experimental Technique of High Voltage

GB********7                 Current Transformer

IEC****9:***1                Enclosure Protection Degree (IP code)

IEEE******2                    Technique Terms and Experiment of Neutral Grounding Device

IEC****1                        Insulation Co-ordination of Transmission and Distribution

                                          Device of High Voltage.

DL/T*******6                 Common Specifications for Purchasing High Voltage

                                         Switch Equipment.

GB*********1               Electrical Equipments Hand-over and Test Standard of

                                           Electrical Device Installation Project.