Specifications

Neutral grounding resistor components are made of stainless steel alloy that is composed of special composition and used special

Combined neutral grounding resisters device

Combined neutral grounding resistor devices are developed by ourselves, and we are the first company to manufacture in china. Both the resistor elements and transformer are in one enclosure. Resister elements are imported and the grounding transformer are manufactured in china, which has low loss, high withstand ability of short circuit surge. We can also supply zero sequence current transformer and disconnector according to customer′s requirement

Obvious advantages: Compacting in structure, saving site area, convenient to layout and installation, it′s specially suitable to reconstruct old substation and to build new power stations in the urban.

Neutral grounding resistor for generators

Limit grounding fault current, prevent from burn of iron core of generators;

Limit transient over-voltage within 2.5p.u.

Suppress resonance over-voltage;

Limit signal phase fault current within 10-15A;

Improve the sensitivity of generator grounding protection, making protection configuration more convenient.

Application

A. The generator is grounded through a signal phase transformer, a low resister element is connected to the secondary side of the transformer.

B. The generator is directly grounded through high resister device.

Inspection and Test

After the placing the equipment ok, open the front plonte that is with nameplate to check the status of internal equipment and connection, as well as give notice to the following items:

1.All packing material should be removed from the box before power on in case there is fire;

2.Inpect whether the insulator and bushing are in good condition or not ,if the damage is found, contact forwarder at once;

3.Check all the electric connection to guarantee the connection is secure;

4.Check whether all fastening screws are tighten;

5.Measure the resistance value and insulation resistance, test the power  frequency withstand voltage in accordance with the criterion. The testing voltage cannot exceed 85% of the factory tested voltage;

6.Close the front plate and get ready for operation.

Maintenance

1.Grounding resistor obtains high reliability and the special maintenance is not required. lt is sug-gested implement maintenance while the main transformer or bus on the power station is power off to overhaul. The maintenance should strictly comply with security operation regulation and security operation criterion;

2.Disconnect resistor from the system;

3.Remove the front plate to check status inside;

4.Clean;

5.Check whether there is damaged insulator or bushing, check the insulation performance of the porcelain bushing by megameter;

6.Check integrity of the resistor component, measure the resistor value and make sure that the deviation is controlled within 10%;

7.Check the internal connection reliability;

8.Check the fastening status of screw;

9.In case of thunder ,storm, earthquake, overload that may cause damage to the components of resistor, staff should do corresponding inspection on the equipment.

Packing, Transportation, Storage

1.The package should be placed on sleeper by normal position and fastened by bolt;

2.The cabinet should be covered with foam to be protected against dust and vapor during the transportation;

3.Keep the equipment in its original package when deliver to installation field, so as to prevent it from possible damage during the transportation;

4.Fix it with fastener to prevent it from resistor looseness during the transportation;

5.Seal the box with lath;

6.Indicate delivery place, equipment name, weight etc on the packing box clearly;

7.All the boxes can be lifted to the common container by forklift;

8.Unload the goods with forklift or crane after its arrival;

9.Inspect the goods after unloading to make sure that the goods is in good condition.