1.       Brief introduction

MRD-FD type neutral grounding resistor cabinet is complete equipment specially used by generators in power plant which adopts high-resistance grounding for neutral. The voltage grade for generator mainly ranges from 6KV to 20KV. When one point of the stator grounds, the device is able to limit the grounding current at a reasonable value, and effectively restraint arc flash transient overvoltage associated with single-phase grounding.

2.       Operation Environment

Apply to indoors

Ambient temperature: between -40 and +40 centigrade

Altitude shall not exceed 3000m

Relative humidity lower than 95% (25 centigrade)

Power grid frequency: 58-62Hz (60Hz system), 48-52Hz (50Hz system)

The installation site shall be free from chemical corrosion, vapor or explosive dust

3. Parameters of Grounding Transformer

Insulation class: H

Temperaturerise: ≤100K

Cooling: AN

Protection Level: for paper-insulated dry type grounding transformer, the PI is divided into IP00 (no enclosure), IP20, and IP23 (with enclosure) .

Insulation level, impedance voltage on-load loss and no-load loss are according to relevant national standards.

Insulation resistance testing: high voltage-low voltage and to earth≥300MΩ, and low voltage-earth≥100MΩ.